@c -*-texinfo-*-
@c This is part of the GNU Guile Reference Manual.
-@c Copyright (C) 1996, 1997, 2000, 2001, 2002, 2003, 2004
+@c Copyright (C) 1996, 1997, 2000, 2001, 2002, 2003, 2004, 2005, 2006
@c Free Software Foundation, Inc.
@c See the file guile.texi for copying conditions.
* Pairs:: Scheme's basic building block.
* Lists:: Special list functions supported by Guile.
* Vectors:: One-dimensional arrays of Scheme objects.
+* Uniform Numeric Vectors:: Vectors with elements of a single numeric type.
+* Bit Vectors:: Vectors of bits.
+* Generalized Vectors:: Treating all vector-like things uniformly.
+* Arrays:: Matrices, etc.
* Records::
* Structures::
-* Arrays:: Arrays of values.
* Dictionary Types:: About dictionary types in general.
* Association Lists:: List-based dictionaries.
* Hash Tables:: Table-based dictionaries.
But beware, if you want to try out these examples, you have to
@dfn{quote} the expressions. More information about quotation is
-available in the section (REFFIXME). The correct way to try these
-examples is as follows.
+available in the section @ref{Expression Syntax}. The correct way
+to try these examples is as follows.
@lisp
'(1 . 2)
@code{#f}.
@end deffn
+@deftypefn {C Function} int scm_is_pair (SCM x)
+Return 1 when @var{x} is a pair; otherwise return 0.
+@end deftypefn
+
The two parts of a pair are traditionally called @dfn{car} and
@dfn{cdr}. They can be retrieved with procedures of the same name
(@code{car} and @code{cdr}), and can be modified with the procedures
@code{set-car!} and @code{set-cdr!}. Since a very common operation in
-Scheme programs is to access the car of a pair, or the car of the cdr of
-a pair, etc., the procedures called @code{caar}, @code{cadr} and so on
-are also predefined.
+Scheme programs is to access the car of a car of a pair, or the car of
+the cdr of a pair, etc., the procedures called @code{caar},
+@code{cadr} and so on are also predefined.
@rnindex car
@rnindex cdr
@deffn {Scheme Procedure} car pair
@deffnx {Scheme Procedure} cdr pair
+@deffnx {C Function} scm_car (pair)
+@deffnx {C Function} scm_cdr (pair)
Return the car or the cdr of @var{pair}, respectively.
@end deffn
-@deffn {Scheme Procedure} caar pair
-@deffnx {Scheme Procedure} cadr pair @dots{}
-@deffnx {Scheme Procedure} cdddar pair
+@deftypefn {C Macro} SCM SCM_CAR (SCM pair)
+@deftypefnx {C Macro} SCM SCM_CDR (SCM pair)
+These two macros are the fastest way to access the car or cdr of a
+pair; they can be thought of as compiling into a single memory
+reference.
+
+These macros do no checking at all. The argument @var{pair} must be a
+valid pair.
+@end deftypefn
+
+@deffn {Scheme Procedure} cddr pair
+@deffnx {Scheme Procedure} cdar pair
+@deffnx {Scheme Procedure} cadr pair
+@deffnx {Scheme Procedure} caar pair
+@deffnx {Scheme Procedure} cdddr pair
+@deffnx {Scheme Procedure} cddar pair
+@deffnx {Scheme Procedure} cdadr pair
+@deffnx {Scheme Procedure} cdaar pair
+@deffnx {Scheme Procedure} caddr pair
+@deffnx {Scheme Procedure} cadar pair
+@deffnx {Scheme Procedure} caadr pair
+@deffnx {Scheme Procedure} caaar pair
@deffnx {Scheme Procedure} cddddr pair
+@deffnx {Scheme Procedure} cdddar pair
+@deffnx {Scheme Procedure} cddadr pair
+@deffnx {Scheme Procedure} cddaar pair
+@deffnx {Scheme Procedure} cdaddr pair
+@deffnx {Scheme Procedure} cdadar pair
+@deffnx {Scheme Procedure} cdaadr pair
+@deffnx {Scheme Procedure} cdaaar pair
+@deffnx {Scheme Procedure} cadddr pair
+@deffnx {Scheme Procedure} caddar pair
+@deffnx {Scheme Procedure} cadadr pair
+@deffnx {Scheme Procedure} cadaar pair
+@deffnx {Scheme Procedure} caaddr pair
+@deffnx {Scheme Procedure} caadar pair
+@deffnx {Scheme Procedure} caaadr pair
+@deffnx {Scheme Procedure} caaaar pair
+@deffnx {C Function} scm_cddr (pair)
+@deffnx {C Function} scm_cdar (pair)
+@deffnx {C Function} scm_cadr (pair)
+@deffnx {C Function} scm_caar (pair)
+@deffnx {C Function} scm_cdddr (pair)
+@deffnx {C Function} scm_cddar (pair)
+@deffnx {C Function} scm_cdadr (pair)
+@deffnx {C Function} scm_cdaar (pair)
+@deffnx {C Function} scm_caddr (pair)
+@deffnx {C Function} scm_cadar (pair)
+@deffnx {C Function} scm_caadr (pair)
+@deffnx {C Function} scm_caaar (pair)
+@deffnx {C Function} scm_cddddr (pair)
+@deffnx {C Function} scm_cdddar (pair)
+@deffnx {C Function} scm_cddadr (pair)
+@deffnx {C Function} scm_cddaar (pair)
+@deffnx {C Function} scm_cdaddr (pair)
+@deffnx {C Function} scm_cdadar (pair)
+@deffnx {C Function} scm_cdaadr (pair)
+@deffnx {C Function} scm_cdaaar (pair)
+@deffnx {C Function} scm_cadddr (pair)
+@deffnx {C Function} scm_caddar (pair)
+@deffnx {C Function} scm_cadadr (pair)
+@deffnx {C Function} scm_cadaar (pair)
+@deffnx {C Function} scm_caaddr (pair)
+@deffnx {C Function} scm_caadar (pair)
+@deffnx {C Function} scm_caaadr (pair)
+@deffnx {C Function} scm_caaaar (pair)
These procedures are compositions of @code{car} and @code{cdr}, where
for example @code{caddr} could be defined by
()
@end lisp
-This example also shows that lists have to be quoted (REFFIXME) when
-written, because they would otherwise be mistakingly taken as procedure
-applications (@pxref{Simple Invocation}).
+This example also shows that lists have to be quoted when written
+(@pxref{Expression Syntax}), because they would otherwise be
+mistakingly taken as procedure applications (@pxref{Simple
+Invocation}).
@node List Predicates
Return @code{#t} iff @var{x} is the empty list, else @code{#f}.
@end deffn
+@deftypefn {C Function} int scm_is_null (SCM x)
+Return 1 when @var{x} is the empty list; otherwise return 0.
+@end deftypefn
+
+
@node List Constructors
@subsubsection List Constructors
@deffn {Scheme Procedure} last-pair lst
@deffnx {C Function} scm_last_pair (lst)
-Return a pointer to the last pair in @var{lst}, signalling an error if
+Return the last pair in @var{lst}, signalling an error if
@var{lst} is circular.
@end deffn
order as in @var{lst}. The order in which @var{pred} is applied to
the list elements is not specified.
-@code{filter!} is allowed, but not required to modify the structure of
+@code{filter} does not change @var{lst}, but the result may share a
+tail with it. @code{filter!} may modify @var{lst} to construct its
+return.
@end deffn
@node List Searching
is constant, whereas lists have an access time linear to the position of the
accessed element in the list.
-Vectors can contain any kind of Scheme object; it is even possible to have
-different types of objects in the same vector. For vectors containing
-vectors, you may wish to use arrays, instead. Note, too, that some array
-procedures operate happily on vectors (@pxref{Arrays}).
+Vectors can contain any kind of Scheme object; it is even possible to
+have different types of objects in the same vector. For vectors
+containing vectors, you may wish to use arrays, instead. Note, too,
+that vectors are the special case of one dimensional non-uniform arrays
+and that most array procedures operate happily on vectors
+(@pxref{Arrays}).
@menu
* Vector Syntax:: Read syntax for vectors.
* Vector Creation:: Dynamic vector creation and validation.
* Vector Accessors:: Accessing and modifying vector contents.
+* Vector Accessing from C:: Ways to work with vectors from C.
@end menu
#("Hello" foo #xdeadbeef)
@end lisp
-Like lists, vectors have to be quoted (REFFIXME):
+Like lists, vectors have to be quoted:
@lisp
'#(a b c) @result{} #(a b c)
@end lisp
@end deffn
-(As an aside, an interesting implementation detail is that the Guile
-reader reads the @code{#(@dots{})} syntax by reading everything but the
-initial @code{#} as a @emph{list}, and then passing the list that
-results to @code{list->vector}. Notice how neatly this fits with the
-similarity between the read (and print) syntaxes for lists and vectors.)
-
The inverse operation is @code{vector->list}:
@rnindex vector->list
is):
@rnindex make-vector
-@deffn {Scheme Procedure} make-vector k [fill]
-@deffnx {C Function} scm_make_vector (k, fill)
-Return a newly allocated vector of @var{k} elements. If a
+@deffn {Scheme Procedure} make-vector len [fill]
+@deffnx {C Function} scm_make_vector (len, fill)
+Return a newly allocated vector of @var{len} elements. If a
second argument is given, then each position is initialized to
@var{fill}. Otherwise the initial contents of each position is
unspecified.
@end deffn
+@deftypefn {C Function} SCM scm_c_make_vector (size_t k, SCM fill)
+Like @code{scm_make_vector}, but the length is given as a @code{size_t}.
+@end deftypefn
+
To check whether an arbitrary Scheme value @emph{is} a vector, use the
@code{vector?} primitive:
@code{#f}.
@end deffn
+@deftypefn {C Function} int scm_is_vector (SCM obj)
+Return non-zero when @var{obj} is a vector, otherwise return
+@code{zero}.
+@end deftypefn
@node Vector Accessors
@subsubsection Accessing and Modifying Vector Contents
Return the number of elements in @var{vector} as an exact integer.
@end deffn
+@deftypefn {C Function} size_t scm_c_vector_length (SCM v)
+Return the number of elements in @var{vector} as a @code{size_t}.
+@end deftypefn
+
@rnindex vector-ref
@deffn {Scheme Procedure} vector-ref vector k
@deffnx {C Function} scm_vector_ref vector k
@end lisp
@end deffn
+@deftypefn {C Function} SCM scm_c_vector_ref (SCM v, size_t k)
+Return the contents of position @var{k} (a @code{size_t}) of
+@var{vector}.
+@end deftypefn
+
A vector created by one of the dynamic vector constructor procedures
(@pxref{Vector Creation}) can be modified using the following
procedures.
@end lisp
@end deffn
+@deftypefn {C Function} void scm_c_vector_set_x (SCM v, size_t k, SCM obj)
+Store @var{obj} in position @var{k} (a @code{size_t}) of @var{v}.
+@end deftypefn
+
@rnindex vector-fill!
@deffn {Scheme Procedure} vector-fill! v fill
@deffnx {C Function} scm_vector_fill_x (v, fill)
returned by @code{vector-fill!} is unspecified.
@end deffn
+@deffn {Scheme Procedure} vector-copy vec
+@deffnx {C Function} scm_vector_copy (vec)
+Return a copy of @var{vec}.
+@end deffn
+
@deffn {Scheme Procedure} vector-move-left! vec1 start1 end1 vec2 start2
@deffnx {C Function} scm_vector_move_left_x (vec1, start1, end1, vec2, start2)
Copy elements from @var{vec1}, positions @var{start1} to @var{end1},
@var{start1} is less than @var{start2}.
@end deffn
+@node Vector Accessing from C
+@subsubsection Vector Accessing from C
+
+A vector can be read and modified from C with the functions
+@code{scm_c_vector_ref} and @code{scm_c_vector_set_x}, for example. In
+addition to these functions, there are two more ways to access vectors
+from C that might be more efficient in certain situations: you can
+restrict yourself to @dfn{simple vectors} and then use the very fast
+@emph{simple vector macros}; or you can use the very general framework
+for accessing all kinds of arrays (@pxref{Accessing Arrays from C}),
+which is more verbose, but can deal efficiently with all kinds of
+vectors (and arrays). For vectors, you can use the
+@code{scm_vector_elements} and @code{scm_vector_writable_elements}
+functions as shortcuts.
+
+@deftypefn {C Function} int scm_is_simple_vector (SCM obj)
+Return non-zero if @var{obj} is a simple vector, else return zero. A
+simple vector is a vector that can be used with the @code{SCM_SIMPLE_*}
+macros below.
+
+The following functions are guaranteed to return simple vectors:
+@code{scm_make_vector}, @code{scm_c_make_vector}, @code{scm_vector},
+@code{scm_list_to_vector}.
+@end deftypefn
+
+@deftypefn {C Macro} size_t SCM_SIMPLE_VECTOR_LENGTH (SCM vec)
+Evaluates to the length of the simple vector @var{vec}. No type
+checking is done.
+@end deftypefn
+
+@deftypefn {C Macro} SCM SCM_SIMPLE_VECTOR_REF (SCM vec, size_t idx)
+Evaluates to the element at position @var{idx} in the simple vector
+@var{vec}. No type or range checking is done.
+@end deftypefn
+
+@deftypefn {C Macro} void SCM_SIMPLE_VECTOR_SET (SCM vec, size_t idx, SCM val)
+Sets the element at position @var{idx} in the simple vector
+@var{vec} to @var{val}. No type or range checking is done.
+@end deftypefn
+
+@deftypefn {C Function} {const SCM *} scm_vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+Acquire a handle for the vector @var{vec} and return a pointer to the
+elements of it. This pointer can only be used to read the elements of
+@var{vec}. When @var{vec} is not a vector, an error is signaled. The
+handle mustr eventually be released with
+@code{scm_array_handle_release}.
+
+The variables pointed to by @var{lenp} and @var{incp} are filled with
+the number of elements of the vector and the increment (number of
+elements) between successive elements, respectively. Successive
+elements of @var{vec} need not be contiguous in their underlying
+``root vector'' returned here; hence the increment is not necessarily
+equal to 1 and may well be negative too (@pxref{Shared Arrays}).
+
+The following example shows the typical way to use this function. It
+creates a list of all elements of @var{vec} (in reverse order).
-@node Records
-@subsection Records
-
-A @dfn{record type} is a first class object representing a user-defined
-data type. A @dfn{record} is an instance of a record type.
-
-@deffn {Scheme Procedure} record? obj
-Return @code{#t} if @var{obj} is a record of any type and @code{#f}
-otherwise.
+@example
+scm_t_array_handle handle;
+size_t i, len;
+ssize_t inc;
+const SCM *elt;
+SCM list;
+
+elt = scm_vector_elements (vec, &handle, &len, &inc);
+list = SCM_EOL;
+for (i = 0; i < len; i++, elt += inc)
+ list = scm_cons (*elt, list);
+scm_array_handle_release (&handle);
+@end example
-Note that @code{record?} may be true of any Scheme value; there is no
-promise that records are disjoint with other Scheme types.
-@end deffn
+@end deftypefn
-@deffn {Scheme Procedure} make-record-type type-name field-names
-Return a @dfn{record-type descriptor}, a value representing a new data
-type disjoint from all others. The @var{type-name} argument must be a
-string, but is only used for debugging purposes (such as the printed
-representation of a record of the new type). The @var{field-names}
-argument is a list of symbols naming the @dfn{fields} of a record of the
-new type. It is an error if the list contains any duplicates. It is
-unspecified how record-type descriptors are represented.
-@end deffn
+@deftypefn {C Function} {SCM *} scm_vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+Like @code{scm_vector_elements} but the pointer can be used to modify
+the vector.
-@deffn {Scheme Procedure} record-constructor rtd [field-names]
-Return a procedure for constructing new members of the type represented
-by @var{rtd}. The returned procedure accepts exactly as many arguments
-as there are symbols in the given list, @var{field-names}; these are
-used, in order, as the initial values of those fields in a new record,
-which is returned by the constructor procedure. The values of any
-fields not named in that list are unspecified. The @var{field-names}
-argument defaults to the list of field names in the call to
-@code{make-record-type} that created the type represented by @var{rtd};
-if the @var{field-names} argument is provided, it is an error if it
-contains any duplicates or any symbols not in the default list.
-@end deffn
+The following example shows the typical way to use this function. It
+fills a vector with @code{#t}.
-@deffn {Scheme Procedure} record-predicate rtd
-Return a procedure for testing membership in the type represented by
-@var{rtd}. The returned procedure accepts exactly one argument and
-returns a true value if the argument is a member of the indicated record
-type; it returns a false value otherwise.
-@end deffn
+@example
+scm_t_array_handle handle;
+size_t i, len;
+ssize_t inc;
+SCM *elt;
+
+elt = scm_vector_writable_elements (vec, &handle, &len, &inc);
+for (i = 0; i < len; i++, elt += inc)
+ *elt = SCM_BOOL_T;
+scm_array_handle_release (&handle);
+@end example
-@deffn {Scheme Procedure} record-accessor rtd field-name
-Return a procedure for reading the value of a particular field of a
-member of the type represented by @var{rtd}. The returned procedure
-accepts exactly one argument which must be a record of the appropriate
-type; it returns the current value of the field named by the symbol
-@var{field-name} in that record. The symbol @var{field-name} must be a
-member of the list of field-names in the call to @code{make-record-type}
-that created the type represented by @var{rtd}.
-@end deffn
+@end deftypefn
+
+@node Uniform Numeric Vectors
+@subsection Uniform Numeric Vectors
+
+A uniform numeric vector is a vector whose elements are all of a single
+numeric type. Guile offers uniform numeric vectors for signed and
+unsigned 8-bit, 16-bit, 32-bit, and 64-bit integers, two sizes of
+floating point values, and complex floating-point numbers of these two
+sizes.
+
+Strings could be regarded as uniform vectors of characters,
+@xref{Strings}. Likewise, bit vectors could be regarded as uniform
+vectors of bits, @xref{Bit Vectors}. Both are sufficiently different
+from uniform numeric vectors that the procedures described here do not
+apply to these two data types. However, both strings and bit vectors
+are generalized vectors, @xref{Generalized Vectors}, and arrays,
+@xref{Arrays}.
+
+Uniform numeric vectors are the special case of one dimensional uniform
+numeric arrays.
+
+Uniform numeric vectors can be useful since they consume less memory
+than the non-uniform, general vectors. Also, since the types they can
+store correspond directly to C types, it is easier to work with them
+efficiently on a low level. Consider image processing as an example,
+where you want to apply a filter to some image. While you could store
+the pixels of an image in a general vector and write a general
+convolution function, things are much more efficient with uniform
+vectors: the convolution function knows that all pixels are unsigned
+8-bit values (say), and can use a very tight inner loop.
+
+That is, when it is written in C. Functions for efficiently working
+with uniform numeric vectors from C are listed at the end of this
+section.
+
+Procedures similar to the vector procedures (@pxref{Vectors}) are
+provided for handling these uniform vectors, but they are distinct
+datatypes and the two cannot be inter-mixed. If you want to work
+primarily with uniform numeric vectors, but want to offer support for
+general vectors as a convenience, you can use one of the
+@code{scm_any_to_*} functions. They will coerce lists and vectors to
+the given type of uniform vector. Alternatively, you can write two
+versions of your code: one that is fast and works only with uniform
+numeric vectors, and one that works with any kind of vector but is
+slower.
+
+One set of the procedures listed below is a generic one: it works with
+all types of uniform numeric vectors. In addition to that, there is a
+set of procedures for each type that only works with that type. Unless
+you really need to the generality of the first set, it is best to use
+the more specific functions. They might not be that much faster, but
+their use can serve as a kind of declaration and makes it easier to
+optimize later on.
+
+The generic set of procedures uses @code{uniform} in its names, the
+specific ones use the tag from the following table.
+
+@table @nicode
+@item u8
+unsigned 8-bit integers
+
+@item s8
+signed 8-bit integers
+
+@item u16
+unsigned 16-bit integers
+
+@item s16
+signed 16-bit integers
+
+@item u32
+unsigned 32-bit integers
+
+@item s32
+signed 32-bit integers
+
+@item u64
+unsigned 64-bit integers
+
+@item s64
+signed 64-bit integers
+
+@item f32
+the C type @code{float}
+
+@item f64
+the C type @code{double}
+
+@item c32
+complex numbers in rectangular form with the real and imaginary part
+being a @code{float}
+
+@item c64
+complex numbers in rectangular form with the real and imaginary part
+being a @code{double}
+
+@end table
+
+The external representation (ie.@: read syntax) for these vectors is
+similar to normal Scheme vectors, but with an additional tag from the
+tabel above indiciating the vector's type. For example,
-@deffn {Scheme Procedure} record-modifier rtd field-name
-Return a procedure for writing the value of a particular field of a
-member of the type represented by @var{rtd}. The returned procedure
-accepts exactly two arguments: first, a record of the appropriate type,
-and second, an arbitrary Scheme value; it modifies the field named by
-the symbol @var{field-name} in that record to contain the given value.
-The returned value of the modifier procedure is unspecified. The symbol
-@var{field-name} must be a member of the list of field-names in the call
-to @code{make-record-type} that created the type represented by
-@var{rtd}.
-@end deffn
+@lisp
+#u16(1 2 3)
+#f64(3.1415 2.71)
+@end lisp
-@deffn {Scheme Procedure} record-type-descriptor record
-Return a record-type descriptor representing the type of the given
-record. That is, for example, if the returned descriptor were passed to
-@code{record-predicate}, the resulting predicate would return a true
-value when passed the given record. Note that it is not necessarily the
-case that the returned descriptor is the one that was passed to
-@code{record-constructor} in the call that created the constructor
-procedure that created the given record.
+Note that the read syntax for floating-point here conflicts with
+@code{#f} for false. In Standard Scheme one can write @code{(1 #f3)}
+for a three element list @code{(1 #f 3)}, but for Guile @code{(1 #f3)}
+is invalid. @code{(1 #f 3)} is almost certainly what one should write
+anyway to make the intention clear, so this is rarely a problem.
+
+@deffn {Scheme Procedure} uniform-vector? obj
+@deffnx {Scheme Procedure} u8vector? obj
+@deffnx {Scheme Procedure} s8vector? obj
+@deffnx {Scheme Procedure} u16vector? obj
+@deffnx {Scheme Procedure} s16vector? obj
+@deffnx {Scheme Procedure} u32vector? obj
+@deffnx {Scheme Procedure} s32vector? obj
+@deffnx {Scheme Procedure} u64vector? obj
+@deffnx {Scheme Procedure} s64vector? obj
+@deffnx {Scheme Procedure} f32vector? obj
+@deffnx {Scheme Procedure} f64vector? obj
+@deffnx {Scheme Procedure} c32vector? obj
+@deffnx {Scheme Procedure} c64vector? obj
+@deffnx {C Function} scm_uniform_vector_p (obj)
+@deffnx {C Function} scm_u8vector_p (obj)
+@deffnx {C Function} scm_s8vector_p (obj)
+@deffnx {C Function} scm_u16vector_p (obj)
+@deffnx {C Function} scm_s16vector_p (obj)
+@deffnx {C Function} scm_u32vector_p (obj)
+@deffnx {C Function} scm_s32vector_p (obj)
+@deffnx {C Function} scm_u64vector_p (obj)
+@deffnx {C Function} scm_s64vector_p (obj)
+@deffnx {C Function} scm_f32vector_p (obj)
+@deffnx {C Function} scm_f64vector_p (obj)
+@deffnx {C Function} scm_c32vector_p (obj)
+@deffnx {C Function} scm_c64vector_p (obj)
+Return @code{#t} if @var{obj} is a homogeneous numeric vector of the
+indicated type.
+@end deffn
+
+@deffn {Scheme Procedure} make-u8vector n [value]
+@deffnx {Scheme Procedure} make-s8vector n [value]
+@deffnx {Scheme Procedure} make-u16vector n [value]
+@deffnx {Scheme Procedure} make-s16vector n [value]
+@deffnx {Scheme Procedure} make-u32vector n [value]
+@deffnx {Scheme Procedure} make-s32vector n [value]
+@deffnx {Scheme Procedure} make-u64vector n [value]
+@deffnx {Scheme Procedure} make-s64vector n [value]
+@deffnx {Scheme Procedure} make-f32vector n [value]
+@deffnx {Scheme Procedure} make-f64vector n [value]
+@deffnx {Scheme Procedure} make-c32vector n [value]
+@deffnx {Scheme Procedure} make-c64vector n [value]
+@deffnx {C Function} scm_make_u8vector n [value]
+@deffnx {C Function} scm_make_s8vector n [value]
+@deffnx {C Function} scm_make_u16vector n [value]
+@deffnx {C Function} scm_make_s16vector n [value]
+@deffnx {C Function} scm_make_u32vector n [value]
+@deffnx {C Function} scm_make_s32vector n [value]
+@deffnx {C Function} scm_make_u64vector n [value]
+@deffnx {C Function} scm_make_s64vector n [value]
+@deffnx {C Function} scm_make_f32vector n [value]
+@deffnx {C Function} scm_make_f64vector n [value]
+@deffnx {C Function} scm_make_c32vector n [value]
+@deffnx {C Function} scm_make_c64vector n [value]
+Return a newly allocated homogeneous numeric vector holding @var{n}
+elements of the indicated type. If @var{value} is given, the vector
+is initialized with that value, otherwise the contents are
+unspecified.
@end deffn
-@deffn {Scheme Procedure} record-type-name rtd
-Return the type-name associated with the type represented by rtd. The
-returned value is @code{eqv?} to the @var{type-name} argument given in
-the call to @code{make-record-type} that created the type represented by
-@var{rtd}.
+@deffn {Scheme Procedure} u8vector value @dots{}
+@deffnx {Scheme Procedure} s8vector value @dots{}
+@deffnx {Scheme Procedure} u16vector value @dots{}
+@deffnx {Scheme Procedure} s16vector value @dots{}
+@deffnx {Scheme Procedure} u32vector value @dots{}
+@deffnx {Scheme Procedure} s32vector value @dots{}
+@deffnx {Scheme Procedure} u64vector value @dots{}
+@deffnx {Scheme Procedure} s64vector value @dots{}
+@deffnx {Scheme Procedure} f32vector value @dots{}
+@deffnx {Scheme Procedure} f64vector value @dots{}
+@deffnx {Scheme Procedure} c32vector value @dots{}
+@deffnx {Scheme Procedure} c64vector value @dots{}
+@deffnx {C Function} scm_u8vector (values)
+@deffnx {C Function} scm_s8vector (values)
+@deffnx {C Function} scm_u16vector (values)
+@deffnx {C Function} scm_s16vector (values)
+@deffnx {C Function} scm_u32vector (values)
+@deffnx {C Function} scm_s32vector (values)
+@deffnx {C Function} scm_u64vector (values)
+@deffnx {C Function} scm_s64vector (values)
+@deffnx {C Function} scm_f32vector (values)
+@deffnx {C Function} scm_f64vector (values)
+@deffnx {C Function} scm_c32vector (values)
+@deffnx {C Function} scm_c64vector (values)
+Return a newly allocated homogeneous numeric vector of the indicated
+type, holding the given parameter @var{value}s. The vector length is
+the number of parameters given.
+@end deffn
+
+@deffn {Scheme Procedure} uniform-vector-length vec
+@deffnx {Scheme Procedure} u8vector-length vec
+@deffnx {Scheme Procedure} s8vector-length vec
+@deffnx {Scheme Procedure} u16vector-length vec
+@deffnx {Scheme Procedure} s16vector-length vec
+@deffnx {Scheme Procedure} u32vector-length vec
+@deffnx {Scheme Procedure} s32vector-length vec
+@deffnx {Scheme Procedure} u64vector-length vec
+@deffnx {Scheme Procedure} s64vector-length vec
+@deffnx {Scheme Procedure} f32vector-length vec
+@deffnx {Scheme Procedure} f64vector-length vec
+@deffnx {Scheme Procedure} c32vector-length vec
+@deffnx {Scheme Procedure} c64vector-length vec
+@deffnx {C Function} scm_uniform_vector_length (vec)
+@deffnx {C Function} scm_u8vector_length (vec)
+@deffnx {C Function} scm_s8vector_length (vec)
+@deffnx {C Function} scm_u16vector_length (vec)
+@deffnx {C Function} scm_s16vector_length (vec)
+@deffnx {C Function} scm_u32vector_length (vec)
+@deffnx {C Function} scm_s32vector_length (vec)
+@deffnx {C Function} scm_u64vector_length (vec)
+@deffnx {C Function} scm_s64vector_length (vec)
+@deffnx {C Function} scm_f32vector_length (vec)
+@deffnx {C Function} scm_f64vector_length (vec)
+@deffnx {C Function} scm_c32vector_length (vec)
+@deffnx {C Function} scm_c64vector_length (vec)
+Return the number of elements in @var{vec}.
+@end deffn
+
+@deffn {Scheme Procedure} uniform-vector-ref vec i
+@deffnx {Scheme Procedure} u8vector-ref vec i
+@deffnx {Scheme Procedure} s8vector-ref vec i
+@deffnx {Scheme Procedure} u16vector-ref vec i
+@deffnx {Scheme Procedure} s16vector-ref vec i
+@deffnx {Scheme Procedure} u32vector-ref vec i
+@deffnx {Scheme Procedure} s32vector-ref vec i
+@deffnx {Scheme Procedure} u64vector-ref vec i
+@deffnx {Scheme Procedure} s64vector-ref vec i
+@deffnx {Scheme Procedure} f32vector-ref vec i
+@deffnx {Scheme Procedure} f64vector-ref vec i
+@deffnx {Scheme Procedure} c32vector-ref vec i
+@deffnx {Scheme Procedure} c64vector-ref vec i
+@deffnx {C Function} scm_uniform_vector_ref (vec i)
+@deffnx {C Function} scm_u8vector_ref (vec i)
+@deffnx {C Function} scm_s8vector_ref (vec i)
+@deffnx {C Function} scm_u16vector_ref (vec i)
+@deffnx {C Function} scm_s16vector_ref (vec i)
+@deffnx {C Function} scm_u32vector_ref (vec i)
+@deffnx {C Function} scm_s32vector_ref (vec i)
+@deffnx {C Function} scm_u64vector_ref (vec i)
+@deffnx {C Function} scm_s64vector_ref (vec i)
+@deffnx {C Function} scm_f32vector_ref (vec i)
+@deffnx {C Function} scm_f64vector_ref (vec i)
+@deffnx {C Function} scm_c32vector_ref (vec i)
+@deffnx {C Function} scm_c64vector_ref (vec i)
+Return the element at index @var{i} in @var{vec}. The first element
+in @var{vec} is index 0.
+@end deffn
+
+@deffn {Scheme Procedure} uniform-vector-set! vec i value
+@deffnx {Scheme Procedure} u8vector-set! vec i value
+@deffnx {Scheme Procedure} s8vector-set! vec i value
+@deffnx {Scheme Procedure} u16vector-set! vec i value
+@deffnx {Scheme Procedure} s16vector-set! vec i value
+@deffnx {Scheme Procedure} u32vector-set! vec i value
+@deffnx {Scheme Procedure} s32vector-set! vec i value
+@deffnx {Scheme Procedure} u64vector-set! vec i value
+@deffnx {Scheme Procedure} s64vector-set! vec i value
+@deffnx {Scheme Procedure} f32vector-set! vec i value
+@deffnx {Scheme Procedure} f64vector-set! vec i value
+@deffnx {Scheme Procedure} c32vector-set! vec i value
+@deffnx {Scheme Procedure} c64vector-set! vec i value
+@deffnx {C Function} scm_uniform_vector_set_x (vec i value)
+@deffnx {C Function} scm_u8vector_set_x (vec i value)
+@deffnx {C Function} scm_s8vector_set_x (vec i value)
+@deffnx {C Function} scm_u16vector_set_x (vec i value)
+@deffnx {C Function} scm_s16vector_set_x (vec i value)
+@deffnx {C Function} scm_u32vector_set_x (vec i value)
+@deffnx {C Function} scm_s32vector_set_x (vec i value)
+@deffnx {C Function} scm_u64vector_set_x (vec i value)
+@deffnx {C Function} scm_s64vector_set_x (vec i value)
+@deffnx {C Function} scm_f32vector_set_x (vec i value)
+@deffnx {C Function} scm_f64vector_set_x (vec i value)
+@deffnx {C Function} scm_c32vector_set_x (vec i value)
+@deffnx {C Function} scm_c64vector_set_x (vec i value)
+Set the element at index @var{i} in @var{vec} to @var{value}. The
+first element in @var{vec} is index 0. The return value is
+unspecified.
@end deffn
-@deffn {Scheme Procedure} record-type-fields rtd
-Return a list of the symbols naming the fields in members of the type
-represented by @var{rtd}. The returned value is @code{equal?} to the
-field-names argument given in the call to @code{make-record-type} that
-created the type represented by @var{rtd}.
-@end deffn
+@deffn {Scheme Procedure} uniform-vector->list vec
+@deffnx {Scheme Procedure} u8vector->list vec
+@deffnx {Scheme Procedure} s8vector->list vec
+@deffnx {Scheme Procedure} u16vector->list vec
+@deffnx {Scheme Procedure} s16vector->list vec
+@deffnx {Scheme Procedure} u32vector->list vec
+@deffnx {Scheme Procedure} s32vector->list vec
+@deffnx {Scheme Procedure} u64vector->list vec
+@deffnx {Scheme Procedure} s64vector->list vec
+@deffnx {Scheme Procedure} f32vector->list vec
+@deffnx {Scheme Procedure} f64vector->list vec
+@deffnx {Scheme Procedure} c32vector->list vec
+@deffnx {Scheme Procedure} c64vector->list vec
+@deffnx {C Function} scm_uniform_vector_to_list (vec)
+@deffnx {C Function} scm_u8vector_to_list (vec)
+@deffnx {C Function} scm_s8vector_to_list (vec)
+@deffnx {C Function} scm_u16vector_to_list (vec)
+@deffnx {C Function} scm_s16vector_to_list (vec)
+@deffnx {C Function} scm_u32vector_to_list (vec)
+@deffnx {C Function} scm_s32vector_to_list (vec)
+@deffnx {C Function} scm_u64vector_to_list (vec)
+@deffnx {C Function} scm_s64vector_to_list (vec)
+@deffnx {C Function} scm_f32vector_to_list (vec)
+@deffnx {C Function} scm_f64vector_to_list (vec)
+@deffnx {C Function} scm_c32vector_to_list (vec)
+@deffnx {C Function} scm_c64vector_to_list (vec)
+Return a newly allocated list holding all elements of @var{vec}.
+@end deffn
+
+@deffn {Scheme Procedure} list->u8vector lst
+@deffnx {Scheme Procedure} list->s8vector lst
+@deffnx {Scheme Procedure} list->u16vector lst
+@deffnx {Scheme Procedure} list->s16vector lst
+@deffnx {Scheme Procedure} list->u32vector lst
+@deffnx {Scheme Procedure} list->s32vector lst
+@deffnx {Scheme Procedure} list->u64vector lst
+@deffnx {Scheme Procedure} list->s64vector lst
+@deffnx {Scheme Procedure} list->f32vector lst
+@deffnx {Scheme Procedure} list->f64vector lst
+@deffnx {Scheme Procedure} list->c32vector lst
+@deffnx {Scheme Procedure} list->c64vector lst
+@deffnx {C Function} scm_list_to_u8vector (lst)
+@deffnx {C Function} scm_list_to_s8vector (lst)
+@deffnx {C Function} scm_list_to_u16vector (lst)
+@deffnx {C Function} scm_list_to_s16vector (lst)
+@deffnx {C Function} scm_list_to_u32vector (lst)
+@deffnx {C Function} scm_list_to_s32vector (lst)
+@deffnx {C Function} scm_list_to_u64vector (lst)
+@deffnx {C Function} scm_list_to_s64vector (lst)
+@deffnx {C Function} scm_list_to_f32vector (lst)
+@deffnx {C Function} scm_list_to_f64vector (lst)
+@deffnx {C Function} scm_list_to_c32vector (lst)
+@deffnx {C Function} scm_list_to_c64vector (lst)
+Return a newly allocated homogeneous numeric vector of the indicated type,
+initialized with the elements of the list @var{lst}.
+@end deffn
+
+@deffn {Scheme Procedure} any->u8vector obj
+@deffnx {Scheme Procedure} any->s8vector obj
+@deffnx {Scheme Procedure} any->u16vector obj
+@deffnx {Scheme Procedure} any->s16vector obj
+@deffnx {Scheme Procedure} any->u32vector obj
+@deffnx {Scheme Procedure} any->s32vector obj
+@deffnx {Scheme Procedure} any->u64vector obj
+@deffnx {Scheme Procedure} any->s64vector obj
+@deffnx {Scheme Procedure} any->f32vector obj
+@deffnx {Scheme Procedure} any->f64vector obj
+@deffnx {Scheme Procedure} any->c32vector obj
+@deffnx {Scheme Procedure} any->c64vector obj
+@deffnx {C Function} scm_any_to_u8vector (obj)
+@deffnx {C Function} scm_any_to_s8vector (obj)
+@deffnx {C Function} scm_any_to_u16vector (obj)
+@deffnx {C Function} scm_any_to_s16vector (obj)
+@deffnx {C Function} scm_any_to_u32vector (obj)
+@deffnx {C Function} scm_any_to_s32vector (obj)
+@deffnx {C Function} scm_any_to_u64vector (obj)
+@deffnx {C Function} scm_any_to_s64vector (obj)
+@deffnx {C Function} scm_any_to_f32vector (obj)
+@deffnx {C Function} scm_any_to_f64vector (obj)
+@deffnx {C Function} scm_any_to_c32vector (obj)
+@deffnx {C Function} scm_any_to_c64vector (obj)
+Return a (maybe newly allocated) uniform numeric vector of the indicated
+type, initialized with the elements of @var{obj}, which must be a list,
+a vector, or a uniform vector. When @var{obj} is already a suitable
+uniform numeric vector, it is returned unchanged.
+@end deffn
+
+@deftypefn {C Function} int scm_is_uniform_vector (SCM uvec)
+Return non-zero when @var{uvec} is a uniform numeric vector, zero
+otherwise.
+@end deftypefn
+
+@deftypefn {C Function} SCM scm_take_u8vector (const scm_t_uint8 *data, size_t len)
+@deftypefnx {C Function} SCM scm_take_s8vector (const scm_t_int8 *data, size_t len)
+@deftypefnx {C Function} SCM scm_take_u16vector (const scm_t_uint16 *data, size_t len)
+@deftypefnx {C Function} SCM scm_take_s168vector (const scm_t_int16 *data, size_t len)
+@deftypefnx {C Function} SCM scm_take_u32vector (const scm_t_uint32 *data, size_t len)
+@deftypefnx {C Function} SCM scm_take_s328vector (const scm_t_int32 *data, size_t len)
+@deftypefnx {C Function} SCM scm_take_u64vector (const scm_t_uint64 *data, size_t len)
+@deftypefnx {C Function} SCM scm_take_s64vector (const scm_t_int64 *data, size_t len)
+@deftypefnx {C Function} SCM scm_take_f32vector (const float *data, size_t len)
+@deftypefnx {C Function} SCM scm_take_f64vector (const double *data, size_t len)
+@deftypefnx {C Function} SCM scm_take_c32vector (const float *data, size_t len)
+@deftypefnx {C Function} SCM scm_take_c64vector (const double *data, size_t len)
+Return a new uniform numeric vector of the indicated type and length
+that uses the memory pointed to by @var{data} to store its elements.
+This memory will eventually be freed with @code{free}. The argument
+@var{len} specifies the number of elements in @var{data}, not its size
+in bytes.
+
+The @code{c32} and @code{c64} variants take a pointer to a C array of
+@code{float}s or @code{double}s. The real parts of the complex numbers
+are at even indices in that array, the corresponding imaginary parts are
+at the following odd index.
+@end deftypefn
+
+@deftypefn {C Function} size_t scm_c_uniform_vector_length (SCM uvec)
+Return the number of elements of @var{uvec} as a @code{size_t}.
+@end deftypefn
+
+@deftypefn {C Function} {const void *} scm_uniform_vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {const scm_t_uint8 *} scm_u8vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {const scm_t_int8 *} scm_s8vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {const scm_t_uint16 *} scm_u16vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {const scm_t_int16 *} scm_s16vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {const scm_t_uint32 *} scm_u32vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {const scm_t_int32 *} scm_s32vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {const scm_t_uint64 *} scm_u64vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {const scm_t_int64 *} scm_s64vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {const float *} scm_f23vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {const double *} scm_f64vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {const float *} scm_c32vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {const double *} scm_c64vector_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+Like @code{scm_vector_elements} (@pxref{Vector Accessing from C}), but
+returns a pointer to the elements of a uniform numeric vector of the
+indicated kind.
+@end deftypefn
+
+@deftypefn {C Function} {void *} scm_uniform_vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {scm_t_uint8 *} scm_u8vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {scm_t_int8 *} scm_s8vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {scm_t_uint16 *} scm_u16vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {scm_t_int16 *} scm_s16vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {scm_t_uint32 *} scm_u32vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {scm_t_int32 *} scm_s32vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {scm_t_uint64 *} scm_u64vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {scm_t_int64 *} scm_s64vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {float *} scm_f23vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {double *} scm_f64vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {float *} scm_c32vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+@deftypefnx {C Function} {double *} scm_c64vector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *lenp, ssize_t *incp)
+Like @code{scm_vector_writable_elements} (@pxref{Vector Accessing from
+C}), but returns a pointer to the elements of a uniform numeric vector
+of the indicated kind.
+@end deftypefn
+
+@deffn {Scheme Procedure} uniform-vector-read! uvec [port_or_fd [start [end]]]
+@deffnx {C Function} scm_uniform_vector_read_x (uvec, port_or_fd, start, end)
+Fill the elements of @var{uvec} by reading
+raw bytes from @var{port-or-fdes}, using host byte order.
+
+The optional arguments @var{start} (inclusive) and @var{end}
+(exclusive) allow a specified region to be read,
+leaving the remainder of the vector unchanged.
+When @var{port-or-fdes} is a port, all specified elements
+of @var{uvec} are attempted to be read, potentially blocking
+while waiting formore input or end-of-file.
+When @var{port-or-fd} is an integer, a single call to
+read(2) is made.
-@node Structures
-@subsection Structures
-@tpindex Structures
+An error is signalled when the last element has only
+been partially filled before reaching end-of-file or in
+the single call to read(2).
-[FIXME: this is pasted in from Tom Lord's original guile.texi and should
-be reviewed]
+@code{uniform-vector-read!} returns the number of elements
+read.
-A @dfn{structure type} is a first class user-defined data type. A
-@dfn{structure} is an instance of a structure type. A structure type is
-itself a structure.
+@var{port-or-fdes} may be omitted, in which case it defaults
+to the value returned by @code{(current-input-port)}.
+@end deffn
-Structures are less abstract and more general than traditional records.
-In fact, in Guile Scheme, records are implemented using structures.
+@deffn {Scheme Procedure} uniform-vector-write uvec [port_or_fd [start [end]]]
+@deffnx {C Function} scm_uniform_vector_write (uvec, port_or_fd, start, end)
+Write the elements of @var{uvec} as raw bytes to
+@var{port-or-fdes}, in the host byte order.
-@menu
-* Structure Concepts:: The structure of Structures
-* Structure Layout:: Defining the layout of structure types
-* Structure Basics:: make-, -ref and -set! procedures for structs
-* Vtables:: Accessing type-specific data
-@end menu
+The optional arguments @var{start} (inclusive)
+and @var{end} (exclusive) allow
+a specified region to be written.
-@node Structure Concepts
-@subsubsection Structure Concepts
+When @var{port-or-fdes} is a port, all specified elements
+of @var{uvec} are attempted to be written, potentially blocking
+while waiting for more room.
+When @var{port-or-fd} is an integer, a single call to
+write(2) is made.
-A structure object consists of a handle, structure data, and a vtable.
-The handle is a Scheme value which points to both the vtable and the
-structure's data. Structure data is a dynamically allocated region of
-memory, private to the structure, divided up into typed fields. A
-vtable is another structure used to hold type-specific data. Multiple
-structures can share a common vtable.
+An error is signalled when the last element has only
+been partially written in the single call to write(2).
-Three concepts are key to understanding structures.
+The number of objects actually written is returned.
+@var{port-or-fdes} may be
+omitted, in which case it defaults to the value returned by
+@code{(current-output-port)}.
+@end deffn
-@itemize @bullet{}
-@item @dfn{layout specifications}
-Layout specifications determine how memory allocated to structures is
-divided up into fields. Programmers must write a layout specification
-whenever a new type of structure is defined.
+@node Bit Vectors
+@subsection Bit Vectors
-@item @dfn{structural accessors}
+@noindent
+Bit vectors are zero-origin, one-dimensional arrays of booleans. They
+are displayed as a sequence of @code{0}s and @code{1}s prefixed by
+@code{#*}, e.g.,
-Structure access is by field number. There is only one set of
-accessors common to all structure objects.
+@example
+(make-bitvector 8 #f) @result{}
+#*00000000
+@end example
-@item @dfn{vtables}
+Bit vectors are are also generalized vectors, @xref{Generalized
+Vectors}, and can thus be used with the array procedures, @xref{Arrays}.
+Bit vectors are the special case of one dimensional bit arrays.
-Vtables, themselves structures, are first class representations of
-disjoint sub-types of structures in general. In most cases, when a
-new structure is created, programmers must specify a vtable for the
-new structure. Each vtable has a field describing the layout of its
-instances. Vtables can have additional, user-defined fields as well.
-@end itemize
+@deffn {Scheme Procedure} bitvector? obj
+@deffnx {C Function} scm_bitvector_p (obj)
+Return @code{#t} when @var{obj} is a bitvector, else
+return @code{#f}.
+@end deffn
+@deftypefn {C Function} int scm_is_bitvector (SCM obj)
+Return @code{1} when @var{obj} is a bitvector, else return @code{0}.
+@end deftypefn
+@deffn {Scheme Procedure} make-bitvector len [fill]
+@deffnx {C Function} scm_make_bitvector (len, fill)
+Create a new bitvector of length @var{len} and
+optionally initialize all elements to @var{fill}.
+@end deffn
-@node Structure Layout
-@subsubsection Structure Layout
+@deftypefn {C Function} SCM scm_c_make_bitvector (size_t len, SCM fill)
+Like @code{scm_make_bitvector}, but the length is given as a
+@code{size_t}.
+@end deftypefn
-When a structure is created, a region of memory is allocated to hold its
-state. The @dfn{layout} of the structure's type determines how that
-memory is divided into fields.
+@deffn {Scheme Procedure} bitvector . bits
+@deffnx {C Function} scm_bitvector (bits)
+Create a new bitvector with the arguments as elements.
+@end deffn
-Each field has a specified type. There are only three types allowed, each
-corresponding to a one letter code. The allowed types are:
+@deffn {Scheme Procedure} bitvector-length vec
+@deffnx {C Function} scm_bitvector_length (vec)
+Return the length of the bitvector @var{vec}.
+@end deffn
-@itemize @bullet{}
-@item 'u' -- unprotected
+@deftypefn {C Function} size_t scm_c_bitvector_length (SCM vec)
+Like @code{scm_bitvector_length}, but the length is returned as a
+@code{size_t}.
+@end deftypefn
-The field holds binary data that is not GC protected.
+@deffn {Scheme Procedure} bitvector-ref vec idx
+@deffnx {C Function} scm_bitvector_ref (vec, idx)
+Return the element at index @var{idx} of the bitvector
+@var{vec}.
+@end deffn
-@item 'p' -- protected
+@deftypefn {C Function} SCM scm_c_bitvector_ref (SCM obj, size_t idx)
+Return the element at index @var{idx} of the bitvector
+@var{vec}.
+@end deftypefn
-The field holds a Scheme value and is GC protected.
+@deffn {Scheme Procedure} bitvector-set! vec idx val
+@deffnx {C Function} scm_bitvector_set_x (vec, idx, val)
+Set the element at index @var{idx} of the bitvector
+@var{vec} when @var{val} is true, else clear it.
+@end deffn
-@item 's' -- self
+@deftypefn {C Function} SCM scm_c_bitvector_set_x (SCM obj, size_t idx, SCM val)
+Set the element at index @var{idx} of the bitvector
+@var{vec} when @var{val} is true, else clear it.
+@end deftypefn
-The field holds a Scheme value and is GC protected. When a structure is
-created with this type of field, the field is initialized to refer to
-the structure's own handle. This kind of field is mainly useful when
-mixing Scheme and C code in which the C code may need to compute a
-structure's handle given only the address of its malloc'd data.
-@end itemize
+@deffn {Scheme Procedure} bitvector-fill! vec val
+@deffnx {C Function} scm_bitvector_fill_x (vec, val)
+Set all elements of the bitvector
+@var{vec} when @var{val} is true, else clear them.
+@end deffn
+@deffn {Scheme Procedure} list->bitvector list
+@deffnx {C Function} scm_list_to_bitvector (list)
+Return a new bitvector initialized with the elements
+of @var{list}.
+@end deffn
-Each field also has an associated access protection. There are only
-three kinds of protection, each corresponding to a one letter code.
-The allowed protections are:
+@deffn {Scheme Procedure} bitvector->list vec
+@deffnx {C Function} scm_bitvector_to_list (vec)
+Return a new list initialized with the elements
+of the bitvector @var{vec}.
+@end deffn
-@itemize @bullet{}
-@item 'w' -- writable
+@deffn {Scheme Procedure} bit-count bool bitvector
+@deffnx {C Function} scm_bit_count (bool, bitvector)
+Return a count of how many entries in @var{bitvector} are equal to
+@var{bool}. For example,
-The field can be read and written.
+@example
+(bit-count #f #*000111000) @result{} 6
+@end example
+@end deffn
-@item 'r' -- readable
+@deffn {Scheme Procedure} bit-position bool bitvector start
+@deffnx {C Function} scm_bit_position (bool, bitvector, start)
+Return the index of the first occurrance of @var{bool} in
+@var{bitvector}, starting from @var{start}. If there is no @var{bool}
+entry between @var{start} and the end of @var{bitvector}, then return
+@code{#f}. For example,
-The field can be read, but not written.
+@example
+(bit-position #t #*000101 0) @result{} 3
+(bit-position #f #*0001111 3) @result{} #f
+@end example
+@end deffn
-@item 'o' -- opaque
+@deffn {Scheme Procedure} bit-invert! bitvector
+@deffnx {C Function} scm_bit_invert_x (bitvector)
+Modify @var{bitvector} by replacing each element with its negation.
+@end deffn
-The field can be neither read nor written. This kind
-of protection is for fields useful only to built-in routines.
-@end itemize
+@deffn {Scheme Procedure} bit-set*! bitvector uvec bool
+@deffnx {C Function} scm_bit_set_star_x (bitvector, uvec, bool)
+Set entries of @var{bitvector} to @var{bool}, with @var{uvec}
+selecting the entries to change. The return value is unspecified.
-A layout specification is described by stringing together pairs
-of letters: one to specify a field type and one to specify a field
-protection. For example, a traditional cons pair type object could
-be described as:
+If @var{uvec} is a bit vector, then those entries where it has
+@code{#t} are the ones in @var{bitvector} which are set to @var{bool}.
+@var{uvec} and @var{bitvector} must be the same length. When
+@var{bool} is @code{#t} it's like @var{uvec} is OR'ed into
+@var{bitvector}. Or when @var{bool} is @code{#f} it can be seen as an
+ANDNOT.
@example
-; cons pairs have two writable fields of Scheme data
-"pwpw"
+(define bv #*01000010)
+(bit-set*! bv #*10010001 #t)
+bv
+@result{} #*11010011
@end example
-A pair object in which the first field is held constant could be:
+If @var{uvec} is a uniform vector of unsigned long integers, then
+they're indexes into @var{bitvector} which are set to @var{bool}.
@example
-"prpw"
+(define bv #*01000010)
+(bit-set*! bv #u(5 2 7) #t)
+bv
+@result{} #*01100111
@end example
+@end deffn
-Binary fields, (fields of type "u"), hold one @dfn{word} each. The
-size of a word is a machine dependent value defined to be equal to the
-value of the C expression: @code{sizeof (long)}.
+@deffn {Scheme Procedure} bit-count* bitvector uvec bool
+@deffnx {C Function} scm_bit_count_star (bitvector, uvec, bool)
+Return a count of how many entries in @var{bitvector} are equal to
+@var{bool}, with @var{uvec} selecting the entries to consider.
-The last field of a structure layout may specify a tail array.
-A tail array is indicated by capitalizing the field's protection
-code ('W', 'R' or 'O'). A tail-array field is replaced by
-a read-only binary data field containing an array size. The array
-size is determined at the time the structure is created. It is followed
-by a corresponding number of fields of the type specified for the
-tail array. For example, a conventional Scheme vector can be
-described as:
-
-@example
-; A vector is an arbitrary number of writable fields holding Scheme
-; values:
-"pW"
-@end example
-
-In the above example, field 0 contains the size of the vector and
-fields beginning at 1 contain the vector elements.
+@var{uvec} is interpreted in the same way as for @code{bit-set*!}
+above. Namely, if @var{uvec} is a bit vector then entries which have
+@code{#t} there are considered in @var{bitvector}. Or if @var{uvec}
+is a uniform vector of unsigned long integers then it's the indexes in
+@var{bitvector} to consider.
-A kind of tagged vector (a constant tag followed by conventional
-vector elements) might be:
+For example,
@example
-"prpW"
+(bit-count* #*01110111 #*11001101 #t) @result{} 3
+(bit-count* #*01110111 #u(7 0 4) #f) @result{} 2
@end example
-
-
-Structure layouts are represented by specially interned symbols whose
-name is a string of type and protection codes. To create a new
-structure layout, use this procedure:
-
-@deffn {Scheme Procedure} make-struct-layout fields
-@deffnx {C Function} scm_make_struct_layout (fields)
-Return a new structure layout object.
-
-@var{fields} must be a string made up of pairs of characters
-strung together. The first character of each pair describes a field
-type, the second a field protection. Allowed types are 'p' for
-GC-protected Scheme data, 'u' for unprotected binary data, and 's' for
-a field that points to the structure itself. Allowed protections
-are 'w' for mutable fields, 'r' for read-only fields, and 'o' for opaque
-fields. The last field protection specification may be capitalized to
-indicate that the field is a tail-array.
@end deffn
+@deftypefn {C Function} {const scm_t_uint32 *} scm_bitvector_elements (SCM vec, scm_t_array_handle *handle, size_t *offp, size_t *lenp, ssize_t *incp)
+Like @code{scm_vector_elements} (@pxref{Vector Accessing from C}), but
+for bitvectors. The variable pointed to by @var{offp} is set to the
+value returned by @code{scm_array_handle_bit_elements_offset}. See
+@code{scm_array_handle_bit_elements} for how to use the returned
+pointer and the offset.
+@end deftypefn
+@deftypefn {C Function} {scm_t_uint32 *} scm_bitvector_writable_elements (SCM vec, scm_t_array_handle *handle, size_t *offp, size_t *lenp, ssize_t *incp)
+Like @code{scm_bitvector_elements}, but the pointer is good for reading
+and writing.
+@end deftypefn
-@node Structure Basics
-@subsubsection Structure Basics
-
-This section describes the basic procedures for creating and accessing
-structures.
-
-@deffn {Scheme Procedure} make-struct vtable tail_array_size . init
-@deffnx {C Function} scm_make_struct (vtable, tail_array_size, init)
-Create a new structure.
-
-@var{type} must be a vtable structure (@pxref{Vtables}).
-
-@var{tail-elts} must be a non-negative integer. If the layout
-specification indicated by @var{type} includes a tail-array,
-this is the number of elements allocated to that array.
-
-The @var{init1}, @dots{} are optional arguments describing how
-successive fields of the structure should be initialized. Only fields
-with protection 'r' or 'w' can be initialized, except for fields of
-type 's', which are automatically initialized to point to the new
-structure itself; fields with protection 'o' can not be initialized by
-Scheme programs.
+@node Generalized Vectors
+@subsection Generalized Vectors
-If fewer optional arguments than initializable fields are supplied,
-fields of type 'p' get default value #f while fields of type 'u' are
-initialized to 0.
+Guile has a number of data types that are generally vector-like:
+strings, uniform numeric vectors, bitvectors, and of course ordinary
+vectors of arbitrary Scheme values. These types are disjoint: a
+Scheme value belongs to at most one of the four types listed above.
-Structs are currently the basic representation for record-like data
-structures in Guile. The plan is to eventually replace them with a
-new representation which will at the same time be easier to use and
-more powerful.
+If you want to gloss over this distinction and want to treat all four
+types with common code, you can use the procedures in this section.
+They work with the @emph{generalized vector} type, which is the union
+of the four vector-like types.
-For more information, see the documentation for @code{make-vtable-vtable}.
+@deffn {Scheme Procedure} generalized-vector? obj
+@deffnx {C Function} scm_generalized_vector_p (obj)
+Return @code{#t} if @var{obj} is a vector, string,
+bitvector, or uniform numeric vector.
@end deffn
-@deffn {Scheme Procedure} struct? x
-@deffnx {C Function} scm_struct_p (x)
-Return @code{#t} iff @var{x} is a structure object, else
-@code{#f}.
+@deffn {Scheme Procedure} generalized-vector-length v
+@deffnx {C Function} scm_generalized_vector_length (v)
+Return the length of the generalized vector @var{v}.
@end deffn
-
-@deffn {Scheme Procedure} struct-ref handle pos
-@deffnx {Scheme Procedure} struct-set! struct n value
-@deffnx {C Function} scm_struct_ref (handle, pos)
-@deffnx {C Function} scm_struct_set_x (struct, n, value)
-Access (or modify) the @var{n}th field of @var{struct}.
-
-If the field is of type 'p', then it can be set to an arbitrary value.
-
-If the field is of type 'u', then it can only be set to a non-negative
-integer value small enough to fit in one machine word.
+@deffn {Scheme Procedure} generalized-vector-ref v idx
+@deffnx {C Function} scm_generalized_vector_ref (v, idx)
+Return the element at index @var{idx} of the
+generalized vector @var{v}.
@end deffn
+@deffn {Scheme Procedure} generalized-vector-set! v idx val
+@deffnx {C Function} scm_generalized_vector_set_x (v, idx, val)
+Set the element at index @var{idx} of the
+generalized vector @var{v} to @var{val}.
+@end deffn
+@deffn {Scheme Procedure} generalized-vector->list v
+@deffnx {C Function} scm_generalized_vector_to_list (v)
+Return a new list whose elements are the elements of the
+generalized vector @var{v}.
+@end deffn
-@node Vtables
-@subsubsection Vtables
+@deftypefn {C Function} int scm_is_generalized_vector (SCM obj)
+Return @code{1} if @var{obj} is a vector, string,
+bitvector, or uniform numeric vector; else return @code{0}.
+@end deftypefn
-Vtables are structures that are used to represent structure types. Each
-vtable contains a layout specification in field
-@code{vtable-index-layout} -- instances of the type are laid out
-according to that specification. Vtables contain additional fields
-which are used only internally to libguile. The variable
-@code{vtable-offset-user} is bound to a field number. Vtable fields
-at that position or greater are user definable.
+@deftypefn {C Function} size_t scm_c_generalized_vector_length (SCM v)
+Return the length of the generalized vector @var{v}.
+@end deftypefn
-@deffn {Scheme Procedure} struct-vtable handle
-@deffnx {C Function} scm_struct_vtable (handle)
-Return the vtable structure that describes the type of @var{struct}.
-@end deffn
+@deftypefn {C Function} SCM scm_c_generalized_vector_ref (SCM v, size_t idx)
+Return the element at index @var{idx} of the generalized vector @var{v}.
+@end deftypefn
-@deffn {Scheme Procedure} struct-vtable? x
-@deffnx {C Function} scm_struct_vtable_p (x)
-Return @code{#t} iff @var{x} is a vtable structure.
-@end deffn
+@deftypefn {C Function} void scm_c_generalized_vector_set_x (SCM v, size_t idx, SCM val)
+Set the element at index @var{idx} of the generalized vector @var{v}
+to @var{val}.
+@end deftypefn
-If you have a vtable structure, @code{V}, you can create an instance of
-the type it describes by using @code{(make-struct V ...)}. But where
-does @code{V} itself come from? One possibility is that @code{V} is an
-instance of a user-defined vtable type, @code{V'}, so that @code{V} is
-created by using @code{(make-struct V' ...)}. Another possibility is
-that @code{V} is an instance of the type it itself describes. Vtable
-structures of the second sort are created by this procedure:
+@deftypefn {C Function} void scm_generalized_vector_get_handle (SCM v, scm_t_array_handle *handle)
+Like @code{scm_array_get_handle} but an error is signalled when @var{v}
+is not of rank one. You can use @code{scm_array_handle_ref} and
+@code{scm_array_handle_set} to read and write the elements of @var{v},
+or you can use functions like @code{scm_array_handle_<foo>_elements} to
+deal with specific types of vectors.
+@end deftypefn
-@deffn {Scheme Procedure} make-vtable-vtable user_fields tail_array_size . init
-@deffnx {C Function} scm_make_vtable_vtable (user_fields, tail_array_size, init)
-Return a new, self-describing vtable structure.
+@node Arrays
+@subsection Arrays
+@tpindex Arrays
-@var{user-fields} is a string describing user defined fields of the
-vtable beginning at index @code{vtable-offset-user}
-(see @code{make-struct-layout}).
+@dfn{Arrays} are a collection of cells organized into an arbitrary
+number of dimensions. Each cell can be accessed in constant time by
+supplying an index for each dimension.
+
+In the current implementation, an array uses a generalized vector for
+the actual storage of its elements. Any kind of generalized vector
+will do, so you can have arrays of uniform numeric values, arrays of
+characters, arrays of bits, and of course, arrays of arbitrary Scheme
+values. For example, arrays with an underlying @code{c64vector} might
+be nice for digital signal processing, while arrays made from a
+@code{u8vector} might be used to hold gray-scale images.
+
+The number of dimensions of an array is called its @dfn{rank}. Thus,
+a matrix is an array of rank 2, while a vector has rank 1. When
+accessing an array element, you have to specify one exact integer for
+each dimension. These integers are called the @dfn{indices} of the
+element. An array specifies the allowed range of indices for each
+dimension via an inclusive lower and upper bound. These bounds can
+well be negative, but the upper bound must be greater than or equal to
+the lower bound minus one. When all lower bounds of an array are
+zero, it is called a @dfn{zero-origin} array.
+
+Arrays can be of rank 0, which could be interpreted as a scalar.
+Thus, a zero-rank array can store exactly one object and the list of
+indices of this element is the empty list.
+
+Arrays contain zero elements when one of their dimensions has a zero
+length. These empty arrays maintain information about their shape: a
+matrix with zero columns and 3 rows is different from a matrix with 3
+columns and zero rows, which again is different from a vector of
+length zero.
+
+Generalized vectors, such as strings, uniform numeric vectors, bit
+vectors and ordinary vectors, are the special case of one dimensional
+arrays.
-@var{tail-size} specifies the size of the tail-array (if any) of
-this vtable.
+@menu
+* Array Syntax::
+* Array Procedures::
+* Shared Arrays::
+* Accessing Arrays from C::
+@end menu
-@var{init1}, @dots{} are the optional initializers for the fields of
-the vtable.
+@node Array Syntax
+@subsubsection Array Syntax
-Vtables have one initializable system field---the struct printer.
-This field comes before the user fields in the initializers passed
-to @code{make-vtable-vtable} and @code{make-struct}, and thus works as
-a third optional argument to @code{make-vtable-vtable} and a fourth to
-@code{make-struct} when creating vtables:
+An array is displayed as @code{#} followed by its rank, followed by a
+tag that describes the underlying vector, optionally followed by
+information about its shape, and finally followed by the cells,
+organized into dimensions using parentheses.
-If the value is a procedure, it will be called instead of the standard
-printer whenever a struct described by this vtable is printed.
-The procedure will be called with arguments STRUCT and PORT.
+In more words, the array tag is of the form
-The structure of a struct is described by a vtable, so the vtable is
-in essence the type of the struct. The vtable is itself a struct with
-a vtable. This could go on forever if it weren't for the
-vtable-vtables which are self-describing vtables, and thus terminate
-the chain.
+@example
+ #<rank><vectag><@@lower><:len><@@lower><:len>...
+@end example
-There are several potential ways of using structs, but the standard
-one is to use three kinds of structs, together building up a type
-sub-system: one vtable-vtable working as the root and one or several
-"types", each with a set of "instances". (The vtable-vtable should be
-compared to the class <class> which is the class of itself.)
+where @code{<rank>} is a positive integer in decimal giving the rank of
+the array. It is omitted when the rank is 1 and the array is non-shared
+and has zero-origin (see below). For shared arrays and for a non-zero
+origin, the rank is always printed even when it is 1 to dinstinguish
+them from ordinary vectors.
-@lisp
-(define ball-root (make-vtable-vtable "pr" 0))
+The @code{<vectag>} part is the tag for a uniform numeric vector, like
+@code{u8}, @code{s16}, etc, @code{b} for bitvectors, or @code{a} for
+strings. It is empty for ordinary vectors.
-(define (make-ball-type ball-color)
- (make-struct ball-root 0
- (make-struct-layout "pw")
- (lambda (ball port)
- (format port "#<a ~A ball owned by ~A>"
- (color ball)
- (owner ball)))
- ball-color))
-(define (color ball) (struct-ref (struct-vtable ball) vtable-offset-user))
-(define (owner ball) (struct-ref ball 0))
+The @code{<@@lower>} part is a @samp{@@} character followed by a signed
+integer in decimal giving the lower bound of a dimension. There is one
+@code{<@@lower>} for each dimension. When all lower bounds are zero,
+all @code{<@@lower>} parts are omitted.
-(define red (make-ball-type 'red))
-(define green (make-ball-type 'green))
+The @code{<:len>} part is a @samp{:} character followed by an unsigned
+integer in decimal giving the length of a dimension. Like for the lower
+bounds, there is one @code{<:len>} for each dimension, and the
+@code{<:len>} part always follows the @code{<@@lower>} part for a
+dimension. Lengths are only then printed when they can't be deduced
+from the nested lists of elements of the array literal, which can happen
+when at least one length is zero.
-(define (make-ball type owner) (make-struct type 0 owner))
+As a special case, an array of rank 0 is printed as
+@code{#0<vectag>(<scalar>)}, where @code{<scalar>} is the result of
+printing the single element of the array.
-(define ball (make-ball green 'Nisse))
-ball @result{} #<a green ball owned by Nisse>
-@end lisp
-@end deffn
+Thus,
-@deffn {Scheme Procedure} struct-vtable-name vtable
-@deffnx {C Function} scm_struct_vtable_name (vtable)
-Return the name of the vtable @var{vtable}.
-@end deffn
+@table @code
+@item #(1 2 3)
+is an ordinary array of rank 1 with lower bound 0 in dimension 0.
+(I.e., a regular vector.)
-@deffn {Scheme Procedure} set-struct-vtable-name! vtable name
-@deffnx {C Function} scm_set_struct_vtable_name_x (vtable, name)
-Set the name of the vtable @var{vtable} to @var{name}.
-@end deffn
+@item #@@2(1 2 3)
+is an ordinary array of rank 1 with lower bound 2 in dimension 0.
-@deffn {Scheme Procedure} struct-vtable-tag handle
-@deffnx {C Function} scm_struct_vtable_tag (handle)
-Return the vtable tag of the structure @var{handle}.
-@end deffn
+@item #2((1 2 3) (4 5 6))
+is a non-uniform array of rank 2; a 3@cross{}3 matrix with index ranges 0..2
+and 0..2.
+@item #u32(0 1 2)
+is a uniform u8 array of rank 1.
-@node Arrays
-@subsection Arrays
-@tpindex Arrays
+@item #2u32@@2@@3((1 2) (2 3))
+is a uniform u8 array of rank 2 with index ranges 2..3 and 3..4.
-@menu
-* Conventional Arrays:: Arrays with arbitrary data.
-* Array Mapping:: Applying a procedure to the contents of an array.
-* Uniform Arrays:: Arrays with data of a single type.
-* Bit Vectors:: Vectors of bits.
-@end menu
+@item #2()
+is a two-dimensional array with index ranges 0..-1 and 0..-1, i.e. both
+dimensions have length zero.
-@node Conventional Arrays
-@subsubsection Conventional Arrays
+@item #2:0:2()
+is a two-dimensional array with index ranges 0..-1 and 0..1, i.e. the
+first dimension has length zero, but the second has length 2.
-@dfn{Conventional arrays} are a collection of cells organized into an
-arbitrary number of dimensions. Each cell can hold any kind of Scheme
-value and can be accessed in constant time by supplying an index for
-each dimension.
+@item #0(12)
+is a rank-zero array with contents 12.
-This contrasts with uniform arrays, which use memory more efficiently
-but can hold data of only a single type. It contrasts also with lists
-where inserting and deleting cells is more efficient, but more time is
-usually required to access a particular cell.
+@end table
-A conventional array is displayed as @code{#} followed by the @dfn{rank}
-(number of dimensions) followed by the cells, organized into dimensions
-using parentheses. The nesting depth of the parentheses is equal to
-the rank.
+@node Array Procedures
+@subsubsection Array Procedures
When an array is created, the range of each dimension must be
specified, e.g., to create a 2@cross{}3 array with a zero-based index:
(make-array 'ho '(0 1) '(0 2)) @result{} #2((ho ho ho) (ho ho ho))
@end example
-A conventional array with one dimension based at zero is identical to
-a vector:
-
-@example
-(make-array 'ho 3) @result{} #(ho ho ho)
-@end example
-
-The following procedures can be used with conventional arrays (or
-vectors). An argument shown as @var{idx}@dots{} means one parameter
-for each dimension in the array. Or a @var{idxlist} is a list of such
+The following procedures can be used with arrays (or vectors). An
+argument shown as @var{idx}@dots{} means one parameter for each
+dimension in the array. A @var{idxlist} argument means a list of such
values, one for each dimension.
-@deffn {Scheme Procedure} array? obj [prot]
-@deffnx {C Function} scm_array_p (obj, prot)
+
+@deffn {Scheme Procedure} array? obj
+@deffnx {C Function} scm_array_p (obj, unused)
Return @code{#t} if the @var{obj} is an array, and @code{#f} if
not.
-The @var{prot} argument is used with uniform arrays (@pxref{Uniform
-Arrays}). If given then the return is @code{#t} if @var{obj} is an
-array and of that prototype.
+The second argument to scm_array_p is there for historical reasons,
+but it is not used. You should always pass @code{SCM_UNDEFINED} as
+its value.
+@end deffn
+
+@deffn {Scheme Procedure} typed-array? obj type
+@deffnx {C Function} scm_typed_array_p (obj, type)
+Return @code{#t} if the @var{obj} is an array of type @var{type}, and
+@code{#f} if not.
+@end deffn
+
+@deftypefn {C Function} int scm_is_array (SCM obj)
+Return @code{1} if the @var{obj} is an array and @code{0} if not.
+@end deftypefn
+
+@deftypefn {C Function} int scm_is_typed_array (SCM obj, SCM type)
+Return @code{0} if the @var{obj} is an array of type @var{type}, and
+@code{1} if not.
+@end deftypefn
+
+@deffn {Scheme Procedure} make-array fill bound @dots{}
+@deffnx {C Function} scm_make_array (fill, bounds)
+Equivalent to @code{(make-typed-array #t @var{fill} @var{bound} ...)}.
@end deffn
-@deffn {Scheme Procedure} make-array initial-value bound @dots{}
+@deffn {Scheme Procedure} make-typed-array type fill bound @dots{}
+@deffnx {C Function} scm_make_typed_array (type, fill, bounds)
Create and return an array that has as many dimensions as there are
-@var{bound}s and fill it with @var{initial-value}.
+@var{bound}s and (maybe) fill it with @var{fill}.
+
+The underlaying storage vector is created according to @var{type},
+which must be a symbol whose name is the `vectag' of the array as
+explained above, or @code{#t} for ordinary, non-specialized arrays.
+
+For example, using the symbol @code{f64} for @var{type} will create an
+array that uses a @code{f64vector} for storing its elements, and
+@code{a} will use a string.
+
+When @var{fill} is not the special @emph{unspecified} value, the new
+array is filled with @var{fill}. Otherwise, the initial contents of
+the array is unspecified. The special @emph{unspecified} value is
+stored in the variable @code{*unspecified*} so that for example
+@code{(make-typed-array 'u32 *unspecified* 4)} creates a uninitialized
+@code{u32} vector of length 4.
+
+Each @var{bound} may be a positive non-zero integer @var{N}, in which
+case the index for that dimension can range from 0 through @var{N-1}; or
+an explicit index range specifier in the form @code{(LOWER UPPER)},
+where both @var{lower} and @var{upper} are integers, possibly less than
+zero, and possibly the same number (however, @var{lower} cannot be
+greater than @var{upper}).
+@end deffn
-Each @var{bound}
-may be a positive non-zero integer @var{N}, in which case the index for
-that dimension can range from 0 through @var{N-1}; or an explicit index
-range specifier in the form @code{(LOWER UPPER)}, where both @var{lower}
-and @var{upper} are integers, possibly less than zero, and possibly the
-same number (however, @var{lower} cannot be greater than @var{upper}).
-See examples above.
+@deffn {Scheme Procedure} list->array dimspec list
+Equivalent to @code{(list->typed-array #t @var{dimspec}
+@var{list})}.
@end deffn
-@c array-ref's type is `compiled-closure'. There's some weird stuff
-@c going on in array.c, too. Let's call it a primitive. -twp
+@deffn {Scheme Procedure} list->typed-array type dimspec list
+@deffnx {C Function} scm_list_to_typed_array (type, dimspec, list)
+Return an array of the type indicated by @var{type} with elements the
+same as those of @var{list}.
+
+The argument @var{dimspec} determines the number of dimensions of the
+array and their lower bounds. When @var{dimspec} is an exact integer,
+it gives the number of dimensions directly and all lower bounds are
+zero. When it is a list of exact integers, then each element is the
+lower index bound of a dimension, and there will be as many dimensions
+as elements in the list.
+@end deffn
+
+@deffn {Scheme Procedure} array-type array
+Return the type of @var{array}. This is the `vectag' used for
+printing @var{array} (or @code{#t} for ordinary arrays) and can be
+used with @code{make-typed-array} to create an array of the same kind
+as @var{array}.
+@end deffn
@deffn {Scheme Procedure} array-ref array idx @dots{}
-@deffnx {Scheme Procedure} uniform-vector-ref vec args
-@deffnx {C Function} scm_uniform_vector_ref (vec, args)
Return the element at @code{(idx @dots{})} in @var{array}.
@example
@example
(define a (make-array #f '(1 2) '(3 4)))
-(array-in-bounds? a 2 3) @result{} #f
+(array-in-bounds? a 2 3) @result{} #t
(array-in-bounds? a 0 0) @result{} #f
@end example
@end deffn
-@c fixme: why do these sigs differ? -ttn 2001/07/19 01:14:12
@deffn {Scheme Procedure} array-set! array obj idx @dots{}
-@deffnx {Scheme Procedure} uniform-array-set1! array obj idxlist
@deffnx {C Function} scm_array_set_x (array, obj, idxlist)
Set the element at @code{(idx @dots{})} in @var{array} to @var{obj}.
The return value is unspecified.
@end example
@end deffn
-@deffn {Scheme Procedure} make-shared-array oldarray mapfunc bound @dots{}
-@deffnx {C Function} scm_make_shared_array (oldarray, mapfunc, boundlist)
-@code{make-shared-array} can be used to create shared subarrays of other
-arrays. The @var{mapper} is a function that translates coordinates in
-the new array into coordinates in the old array. A @var{mapper} must be
-linear, and its range must stay within the bounds of the old array, but
-it can be otherwise arbitrary. A simple example:
-
-@lisp
-(define fred (make-array #f 8 8))
-(define freds-diagonal
- (make-shared-array fred (lambda (i) (list i i)) 8))
-(array-set! freds-diagonal 'foo 3)
-(array-ref fred 3 3) @result{} foo
-(define freds-center
- (make-shared-array fred (lambda (i j) (list (+ 3 i) (+ 3 j))) 2 2))
-(array-ref freds-center 0 0) @result{} foo
-@end lisp
-@end deffn
-
-@deffn {Scheme Procedure} shared-array-increments array
-@deffnx {C Function} scm_shared_array_increments (array)
-For each dimension, return the distance between elements in the root vector.
-@end deffn
-
-@deffn {Scheme Procedure} shared-array-offset array
-@deffnx {C Function} scm_shared_array_offset (array)
-Return the root vector index of the first element in the array.
-@end deffn
-
-@deffn {Scheme Procedure} shared-array-root array
-@deffnx {C Function} scm_shared_array_root (array)
-Return the root vector of a shared array.
-@end deffn
-
-@deffn {Scheme Procedure} transpose-array array dim1 @dots{}
-@deffnx {C Function} scm_transpose_array (array, dimlist)
-Return an array sharing contents with @var{array}, but with
-dimensions arranged in a different order. There must be one
-@var{dim} argument for each dimension of @var{array}.
-@var{dim1}, @var{dim2}, @dots{} should be integers between 0
-and the rank of the array to be returned. Each integer in that
-range must appear at least once in the argument list.
-
-The values of @var{dim1}, @var{dim2}, @dots{} correspond to
-dimensions in the array to be returned, and their positions in the
-argument list to dimensions of @var{array}. Several @var{dim}s
-may have the same value, in which case the returned array will
-have smaller rank than @var{array}.
-
-@lisp
-(transpose-array '#2((a b) (c d)) 1 0) @result{} #2((a c) (b d))
-(transpose-array '#2((a b) (c d)) 0 0) @result{} #1(a d)
-(transpose-array '#3(((a b c) (d e f)) ((1 2 3) (4 5 6))) 1 1 0) @result{}
- #2((a 4) (b 5) (c 6))
-@end lisp
-@end deffn
-
@deffn {Scheme Procedure} enclose-array array dim1 @dots{}
@deffnx {C Function} scm_enclose_array (array, dimlist)
@var{dim1}, @var{dim2} @dots{} should be nonnegative integers less than
@deffn {Scheme Procedure} array-rank obj
@deffnx {C Function} scm_array_rank (obj)
-Return the number of dimensions of an array @var{obj}, or if @var{obj}
-is not an array then return 0.
+Return the rank of @var{array}.
@end deffn
+@deftypefn {C Function} size_t scm_c_array_rank (SCM array)
+Return the rank of @var{array} as a @code{size_t}.
+@end deftypefn
+
@deffn {Scheme Procedure} array->list array
@deffnx {C Function} scm_array_to_list (array)
Return a list consisting of all the elements, in order, of
Return @code{#t} if all arguments are arrays with the same shape, the
same type, and have corresponding elements which are either
@code{equal?} or @code{array-equal?}. This function differs from
-@code{equal?} in that a one dimensional shared array may be
-@var{array-equal?} but not @var{equal?} to a vector or uniform vector.
+@code{equal?} (@pxref{Equality}) in that a one dimensional shared
+array may be @code{array-equal?} but not @code{equal?} to a vector or
+uniform vector.
@end deffn
-@deffn {Scheme Procedure} array-contents array [strict]
-@deffnx {C Function} scm_array_contents (array, strict)
-If @var{array} may be @dfn{unrolled} into a one dimensional shared array
-without changing their order (last subscript changing fastest), then
-@code{array-contents} returns that shared array, otherwise it returns
-@code{#f}. All arrays made by @code{make-array} and
-@code{make-uniform-array} may be unrolled, some arrays made by
-@code{make-shared-array} may not be.
-
-If the optional argument @var{strict} is provided, a shared array will
-be returned only if its elements are stored internally contiguous in
-memory.
-@end deffn
-
-@node Array Mapping
-@subsubsection Array Mapping
-
@c FIXME: array-map! accepts no source arrays at all, and in that
@c case makes calls "(proc)". Is that meant to be a documented
@c feature?
@end example
@end deffn
-@node Uniform Arrays
-@subsubsection Uniform Arrays
-@tpindex Uniform Arrays
+@deffn {Scheme Procedure} uniform-array-read! ra [port_or_fd [start [end]]]
+@deffnx {C Function} scm_uniform_array_read_x (ra, port_or_fd, start, end)
+Attempt to read all elements of @var{ura}, in lexicographic order, as
+binary objects from @var{port-or-fdes}.
+If an end of file is encountered,
+the objects up to that point are put into @var{ura}
+(starting at the beginning) and the remainder of the array is
+unchanged.
+
+The optional arguments @var{start} and @var{end} allow
+a specified region of a vector (or linearized array) to be read,
+leaving the remainder of the vector unchanged.
+
+@code{uniform-array-read!} returns the number of objects read.
+@var{port-or-fdes} may be omitted, in which case it defaults to the value
+returned by @code{(current-input-port)}.
+@end deffn
+
+@deffn {Scheme Procedure} uniform-array-write v [port_or_fd [start [end]]]
+@deffnx {C Function} scm_uniform_array_write (v, port_or_fd, start, end)
+Writes all elements of @var{ura} as binary objects to
+@var{port-or-fdes}.
+
+The optional arguments @var{start}
+and @var{end} allow
+a specified region of a vector (or linearized array) to be written.
+
+The number of objects actually written is returned.
+@var{port-or-fdes} may be
+omitted, in which case it defaults to the value returned by
+@code{(current-output-port)}.
+@end deffn
+
+@node Shared Arrays
+@subsubsection Shared Arrays
+
+@deffn {Scheme Procedure} make-shared-array oldarray mapfunc bound @dots{}
+@deffnx {C Function} scm_make_shared_array (oldarray, mapfunc, boundlist)
+Return a new array which shares the storage of @var{oldarray}.
+Changes made through either affect the same underlying storage. The
+@var{bound@dots{}} arguments are the shape of the new array, the same
+as @code{make-array} (@pxref{Array Procedures}).
+
+@var{mapfunc} translates coordinates from the new array to the
+@var{oldarray}. It's called as @code{(@var{mapfunc} newidx1 @dots{})}
+with one parameter for each dimension of the new array, and should
+return a list of indices for @var{oldarray}, one for each dimension of
+@var{oldarray}.
+
+@var{mapfunc} must be affine linear, meaning that each @var{oldarray}
+index must be formed by adding integer multiples (possibly negative)
+of some or all of @var{newidx1} etc, plus a possible integer offset.
+The multiples and offset must be the same in each call.
+
+@sp 1
+One good use for a shared array is to restrict the range of some
+dimensions, so as to apply say @code{array-for-each} or
+@code{array-fill!} to only part of an array. The plain @code{list}
+function can be used for @var{mapfunc} in this case, making no changes
+to the index values. For example,
+
+@example
+(make-shared-array #2((a b c) (d e f) (g h i)) list 3 2)
+@result{} #2((a b) (d e) (g h))
+@end example
+
+The new array can have fewer dimensions than @var{oldarray}, for
+example to take a column from an array.
+
+@example
+(make-shared-array #2((a b c) (d e f) (g h i))
+ (lambda (i) (list i 2))
+ '(0 2))
+@result{} #1(c f i)
+@end example
+
+A diagonal can be taken by using the single new array index for both
+row and column in the old array. For example,
+
+@example
+(make-shared-array #2((a b c) (d e f) (g h i))
+ (lambda (i) (list i i))
+ '(0 2))
+@result{} #1(a e i)
+@end example
+
+Dimensions can be increased by for instance considering portions of a
+one dimensional array as rows in a two dimensional array.
+(@code{array-contents} below can do the opposite, flattening an
+array.)
+
+@example
+(make-shared-array #1(a b c d e f g h i j k l)
+ (lambda (i j) (list (+ (* i 3) j)))
+ 4 3)
+@result{} #2((a b c) (d e f) (g h i) (j k l))
+@end example
+
+By negating an index the order that elements appear can be reversed.
+The following just reverses the column order,
+
+@example
+(make-shared-array #2((a b c) (d e f) (g h i))
+ (lambda (i j) (list i (- 2 j)))
+ 3 3)
+@result{} #2((c b a) (f e d) (i h g))
+@end example
+
+A fixed offset on indexes allows for instance a change from a 0 based
+to a 1 based array,
+
+@example
+(define x #2((a b c) (d e f) (g h i)))
+(define y (make-shared-array x
+ (lambda (i j) (list (1- i) (1- j)))
+ '(1 3) '(1 3)))
+(array-ref x 0 0) @result{} a
+(array-ref y 1 1) @result{} a
+@end example
+
+A multiple on an index allows every Nth element of an array to be
+taken. The following is every third element,
+
+@example
+(make-shared-array #1(a b c d e f g h i j k l)
+ (lambda (i) (list (* i 3)))
+ 4)
+@result{} #1(a d g j)
+@end example
+
+The above examples can be combined to make weird and wonderful
+selections from an array, but it's important to note that because
+@var{mapfunc} must be affine linear, arbitrary permutations are not
+possible.
+
+In the current implementation, @var{mapfunc} is not called for every
+access to the new array but only on some sample points to establish a
+base and stride for new array indices in @var{oldarray} data. A few
+sample points are enough because @var{mapfunc} is linear.
+@end deffn
+
+@deffn {Scheme Procedure} shared-array-increments array
+@deffnx {C Function} scm_shared_array_increments (array)
+For each dimension, return the distance between elements in the root vector.
+@end deffn
+
+@deffn {Scheme Procedure} shared-array-offset array
+@deffnx {C Function} scm_shared_array_offset (array)
+Return the root vector index of the first element in the array.
+@end deffn
+
+@deffn {Scheme Procedure} shared-array-root array
+@deffnx {C Function} scm_shared_array_root (array)
+Return the root vector of a shared array.
+@end deffn
+
+@deffn {Scheme Procedure} array-contents array [strict]
+@deffnx {C Function} scm_array_contents (array, strict)
+If @var{array} may be @dfn{unrolled} into a one dimensional shared array
+without changing their order (last subscript changing fastest), then
+@code{array-contents} returns that shared array, otherwise it returns
+@code{#f}. All arrays made by @code{make-array} and
+@code{make-typed-array} may be unrolled, some arrays made by
+@code{make-shared-array} may not be.
+
+If the optional argument @var{strict} is provided, a shared array will
+be returned only if its elements are stored internally contiguous in
+memory.
+@end deffn
+
+@deffn {Scheme Procedure} transpose-array array dim1 @dots{}
+@deffnx {C Function} scm_transpose_array (array, dimlist)
+Return an array sharing contents with @var{array}, but with
+dimensions arranged in a different order. There must be one
+@var{dim} argument for each dimension of @var{array}.
+@var{dim1}, @var{dim2}, @dots{} should be integers between 0
+and the rank of the array to be returned. Each integer in that
+range must appear at least once in the argument list.
+
+The values of @var{dim1}, @var{dim2}, @dots{} correspond to
+dimensions in the array to be returned, and their positions in the
+argument list to dimensions of @var{array}. Several @var{dim}s
+may have the same value, in which case the returned array will
+have smaller rank than @var{array}.
+
+@lisp
+(transpose-array '#2((a b) (c d)) 1 0) @result{} #2((a c) (b d))
+(transpose-array '#2((a b) (c d)) 0 0) @result{} #1(a d)
+(transpose-array '#3(((a b c) (d e f)) ((1 2 3) (4 5 6))) 1 1 0) @result{}
+ #2((a 4) (b 5) (c 6))
+@end lisp
+@end deffn
+
+@node Accessing Arrays from C
+@subsubsection Accessing Arrays from C
+
+Arrays, especially uniform numeric arrays, are useful to efficiently
+represent large amounts of rectangularily organized information, such as
+matrices, images, or generally blobs of binary data. It is desirable to
+access these blobs in a C like manner so that they can be handed to
+external C code such as linear algebra libraries or image processing
+routines.
+
+While pointers to the elements of an array are in use, the array itself
+must be protected so that the pointer remains valid. Such a protected
+array is said to be @dfn{reserved}. A reserved array can be read but
+modifications to it that would cause the pointer to its elements to
+become invalid are prevented. When you attempt such a modification, an
+error is signalled.
+
+(This is similar to locking the array while it is in use, but without
+the danger of a deadlock. In a multi-threaded program, you will need
+additional synchronization to avoid modifying reserved arrays.)
+
+You must take care to always unreserve an array after reserving it,
+also in the presence of non-local exits. To simplify this, reserving
+and unreserving work like a dynwind context (@pxref{Dynamic Wind}): a
+call to @code{scm_array_get_handle} can be thought of as beginning a
+dynwind context and @code{scm_array_handle_release} as ending it.
+When a non-local exit happens between these two calls, the array is
+implicitely unreserved.
+
+That is, you need to properly pair reserving and unreserving in your
+code, but you don't need to worry about non-local exits.
+
+These calls and other pairs of calls that establish dynwind contexts
+need to be properly nested. If you begin a context prior to reserving
+an array, you need to unreserve the array before ending the context.
+Likewise, when reserving two or more arrays in a certain order, you
+need to unreserve them in the opposite order.
+
+Once you have reserved an array and have retrieved the pointer to its
+elements, you must figure out the layout of the elements in memory.
+Guile allows slices to be taken out of arrays without actually making a
+copy, such as making an alias for the diagonal of a matrix that can be
+treated as a vector. Arrays that result from such an operation are not
+stored contiguously in memory and when working with their elements
+directly, you need to take this into account.
+
+The layout of array elements in memory can be defined via a
+@emph{mapping function} that computes a scalar position from a vector of
+indices. The scalar position then is the offset of the element with the
+given indices from the start of the storage block of the array.
+
+In Guile, this mapping function is restricted to be @dfn{affine}: all
+mapping functions of Guile arrays can be written as @code{p = b +
+c[0]*i[0] + c[1]*i[1] + ... + c[n-1]*i[n-1]} where @code{i[k]} is the
+@nicode{k}th index and @code{n} is the rank of the array. For
+example, a matrix of size 3x3 would have @code{b == 0}, @code{c[0] ==
+3} and @code{c[1] == 1}. When you transpose this matrix (with
+@code{transpose-array}, say), you will get an array whose mapping
+function has @code{b == 0}, @code{c[0] == 1} and @code{c[1] == 3}.
+
+The function @code{scm_array_handle_dims} gives you (indirect) access to
+the coefficients @code{c[k]}.
+
+@c XXX
+Note that there are no functions for accessing the elements of a
+character array yet. Once the string implementation of Guile has been
+changed to use Unicode, we will provide them.
+
+@deftp {C Type} scm_t_array_handle
+This is a structure type that holds all information necessary to manage
+the reservation of arrays as explained above. Structures of this type
+must be allocated on the stack and must only be accessed by the
+functions listed below.
+@end deftp
+
+@deftypefn {C Function} void scm_array_get_handle (SCM array, scm_t_array_handle *handle)
+Reserve @var{array}, which must be an array, and prepare @var{handle} to
+be used with the functions below. You must eventually call
+@code{scm_array_handle_release} on @var{handle}, and do this in a
+properly nested fashion, as explained above. The structure pointed to
+by @var{handle} does not need to be initialized before calling this
+function.
+@end deftypefn
+
+@deftypefn {C Function} void scm_array_handle_release (scm_t_array_handle *handle)
+End the array reservation represented by @var{handle}. After a call to
+this function, @var{handle} might be used for another reservation.
+@end deftypefn
+
+@deftypefn {C Function} size_t scm_array_handle_rank (scm_t_array_handle *handle)
+Return the rank of the array represented by @var{handle}.
+@end deftypefn
+
+@deftp {C Type} scm_t_array_dim
+This structure type holds information about the layout of one dimension
+of an array. It includes the following fields:
+
+@table @code
+@item ssize_t lbnd
+@itemx ssize_t ubnd
+The lower and upper bounds (both inclusive) of the permissible index
+range for the given dimension. Both values can be negative, but
+@var{lbnd} is always less than or equal to @var{ubnd}.
+
+@item ssize_t inc
+The distance from one element of this dimension to the next. Note, too,
+that this can be negative.
+@end table
+@end deftp
+
+@deftypefn {C Function} {const scm_t_array_dim *} scm_array_handle_dims (scm_t_array_handle *handle)
+Return a pointer to a C vector of information about the dimensions of
+the array represented by @var{handle}. This pointer is valid as long as
+the array remains reserved. As explained above, the
+@code{scm_t_array_dim} structures returned by this function can be used
+calculate the position of an element in the storage block of the array
+from its indices.
+
+This position can then be used as an index into the C array pointer
+returned by the various @code{scm_array_handle_<foo>_elements}
+functions, or with @code{scm_array_handle_ref} and
+@code{scm_array_handle_set}.
+
+Here is how one can compute the position @var{pos} of an element given
+its indices in the vector @var{indices}:
+
+@example
+ssize_t indices[RANK];
+scm_t_array_dim *dims;
+ssize_t pos;
+size_t i;
+
+pos = 0;
+for (i = 0; i < RANK; i++)
+ @{
+ if (indices[i] < dims[i].lbnd || indices[i] > dims[i].ubnd)
+ out_of_range ();
+ pos += (indices[i] - dims[i].lbnd) * dims[i].inc;
+ @}
+@end example
+@end deftypefn
+
+@deftypefn {C Function} ssize_t scm_array_handle_pos (scm_t_array_handle *handle, SCM indices)
+Compute the position corresponding to @var{indices}, a list of
+indices. The position is computed as described above for
+@code{scm_array_handle_dims}. The number of the indices and their
+range is checked and an approrpiate error is signalled for invalid
+indices.
+@end deftypefn
+
+@deftypefn {C Function} SCM scm_array_handle_ref (scm_t_array_handle *handle, ssize_t pos)
+Return the element at position @var{pos} in the storage block of the
+array represented by @var{handle}. Any kind of array is acceptable. No
+range checking is done on @var{pos}.
+@end deftypefn
+
+@deftypefn {C Function} void scm_array_handle_set (scm_t_array_handle *handle, ssize_t pos, SCM val)
+Set the element at position @var{pos} in the storage block of the array
+represented by @var{handle} to @var{val}. Any kind of array is
+acceptable. No range checking is done on @var{pos}. An error is
+signalled when the array can not store @var{val}.
+@end deftypefn
+
+@deftypefn {C Function} {const SCM *} scm_array_handle_elements (scm_t_array_handle *handle)
+Return a pointer to the elements of a ordinary array of general Scheme
+values (i.e., a non-uniform array) for reading. This pointer is valid
+as long as the array remains reserved.
+@end deftypefn
+
+@deftypefn {C Function} {SCM *} scm_array_handle_writable_elements (scm_t_array_handle *handle)
+Like @code{scm_array_handle_elements}, but the pointer is good for
+reading and writing.
+@end deftypefn
+
+@deftypefn {C Function} {const void *} scm_array_handle_uniform_elements (scm_t_array_handle *handle)
+Return a pointer to the elements of a uniform numeric array for reading.
+This pointer is valid as long as the array remains reserved. The size
+of each element is given by @code{scm_array_handle_uniform_element_size}.
+@end deftypefn
+
+@deftypefn {C Function} {void *} scm_array_handle_uniform_writable_elements (scm_t_array_handle *handle)
+Like @code{scm_array_handle_uniform_elements}, but the pointer is good
+reading and writing.
+@end deftypefn
+
+@deftypefn {C Function} size_t scm_array_handle_uniform_element_size (scm_t_array_handle *handle)
+Return the size of one element of the uniform numeric array represented
+by @var{handle}.
+@end deftypefn
+
+@deftypefn {C Function} {const scm_t_uint8 *} scm_array_handle_u8_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {const scm_t_int8 *} scm_array_handle_s8_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {const scm_t_uint16 *} scm_array_handle_u16_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {const scm_t_int16 *} scm_array_handle_s16_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {const scm_t_uint32 *} scm_array_handle_u32_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {const scm_t_int32 *} scm_array_handle_s32_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {const scm_t_uint64 *} scm_array_handle_u64_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {const scm_t_int64 *} scm_array_handle_s64_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {const float *} scm_array_handle_f32_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {const double *} scm_array_handle_f64_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {const float *} scm_array_handle_c32_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {const double *} scm_array_handle_c64_elements (scm_t_array_handle *handle)
+Return a pointer to the elements of a uniform numeric array of the
+indicated kind for reading. This pointer is valid as long as the array
+remains reserved.
+
+The pointers for @code{c32} and @code{c64} uniform numeric arrays point
+to pairs of floating point numbers. The even index holds the real part,
+the odd index the imaginary part of the complex number.
+@end deftypefn
+
+@deftypefn {C Function} {scm_t_uint8 *} scm_array_handle_u8_writable_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {scm_t_int8 *} scm_array_handle_s8_writable_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {scm_t_uint16 *} scm_array_handle_u16_writable_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {scm_t_int16 *} scm_array_handle_s16_writable_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {scm_t_uint32 *} scm_array_handle_u32_writable_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {scm_t_int32 *} scm_array_handle_s32_writable_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {scm_t_uint64 *} scm_array_handle_u64_writable_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {scm_t_int64 *} scm_array_handle_s64_writable_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {float *} scm_array_handle_f32_writable_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {double *} scm_array_handle_f64_writable_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {float *} scm_array_handle_c32_writable_elements (scm_t_array_handle *handle)
+@deftypefnx {C Function} {double *} scm_array_handle_c64_writable_elements (scm_t_array_handle *handle)
+Like @code{scm_array_handle_<kind>_elements}, but the pointer is good
+for reading and writing.
+@end deftypefn
+
+@deftypefn {C Function} {const scm_t_uint32 *} scm_array_handle_bit_elements (scm_t_array_handle *handle)
+Return a pointer to the words that store the bits of the represented
+array, which must be a bit array.
+
+Unlike other arrays, bit arrays have an additional offset that must be
+figured into index calculations. That offset is returned by
+@code{scm_array_handle_bit_elements_offset}.
+
+To find a certain bit you first need to calculate its position as
+explained above for @code{scm_array_handle_dims} and then add the
+offset. This gives the absolute position of the bit, which is always a
+non-negative integer.
+
+Each word of the bit array storage block contains exactly 32 bits, with
+the least significant bit in that word having the lowest absolute
+position number. The next word contains the next 32 bits.
+
+Thus, the following code can be used to access a bit whose position
+according to @code{scm_array_handle_dims} is given in @var{pos}:
+
+@example
+SCM bit_array;
+scm_t_array_handle handle;
+scm_t_uint32 *bits;
+ssize_t pos;
+size_t abs_pos;
+size_t word_pos, mask;
+
+scm_array_get_handle (&bit_array, &handle);
+bits = scm_array_handle_bit_elements (&handle);
+
+pos = ...
+abs_pos = pos + scm_array_handle_bit_elements_offset (&handle);
+word_pos = abs_pos / 32;
+mask = 1L << (abs_pos % 32);
+
+if (bits[word_pos] & mask)
+ /* bit is set. */
+
+scm_array_handle_release (&handle);
+@end example
+
+@end deftypefn
+
+@deftypefn {C Function} {scm_t_uint32 *} scm_array_handle_bit_writable_elements (scm_t_array_handle *handle)
+Like @code{scm_array_handle_bit_elements} but the pointer is good for
+reading and writing. You must take care not to modify bits outside of
+the allowed index range of the array, even for contiguous arrays.
+@end deftypefn
+
+@node Records
+@subsection Records
+
+A @dfn{record type} is a first class object representing a user-defined
+data type. A @dfn{record} is an instance of a record type.
+
+@deffn {Scheme Procedure} record? obj
+Return @code{#t} if @var{obj} is a record of any type and @code{#f}
+otherwise.
+
+Note that @code{record?} may be true of any Scheme value; there is no
+promise that records are disjoint with other Scheme types.
+@end deffn
+
+@deffn {Scheme Procedure} make-record-type type-name field-names
+Return a @dfn{record-type descriptor}, a value representing a new data
+type disjoint from all others. The @var{type-name} argument must be a
+string, but is only used for debugging purposes (such as the printed
+representation of a record of the new type). The @var{field-names}
+argument is a list of symbols naming the @dfn{fields} of a record of the
+new type. It is an error if the list contains any duplicates. It is
+unspecified how record-type descriptors are represented.
+@end deffn
+
+@deffn {Scheme Procedure} record-constructor rtd [field-names]
+Return a procedure for constructing new members of the type represented
+by @var{rtd}. The returned procedure accepts exactly as many arguments
+as there are symbols in the given list, @var{field-names}; these are
+used, in order, as the initial values of those fields in a new record,
+which is returned by the constructor procedure. The values of any
+fields not named in that list are unspecified. The @var{field-names}
+argument defaults to the list of field names in the call to
+@code{make-record-type} that created the type represented by @var{rtd};
+if the @var{field-names} argument is provided, it is an error if it
+contains any duplicates or any symbols not in the default list.
+@end deffn
+
+@deffn {Scheme Procedure} record-predicate rtd
+Return a procedure for testing membership in the type represented by
+@var{rtd}. The returned procedure accepts exactly one argument and
+returns a true value if the argument is a member of the indicated record
+type; it returns a false value otherwise.
+@end deffn
+
+@deffn {Scheme Procedure} record-accessor rtd field-name
+Return a procedure for reading the value of a particular field of a
+member of the type represented by @var{rtd}. The returned procedure
+accepts exactly one argument which must be a record of the appropriate
+type; it returns the current value of the field named by the symbol
+@var{field-name} in that record. The symbol @var{field-name} must be a
+member of the list of field-names in the call to @code{make-record-type}
+that created the type represented by @var{rtd}.
+@end deffn
+
+@deffn {Scheme Procedure} record-modifier rtd field-name
+Return a procedure for writing the value of a particular field of a
+member of the type represented by @var{rtd}. The returned procedure
+accepts exactly two arguments: first, a record of the appropriate type,
+and second, an arbitrary Scheme value; it modifies the field named by
+the symbol @var{field-name} in that record to contain the given value.
+The returned value of the modifier procedure is unspecified. The symbol
+@var{field-name} must be a member of the list of field-names in the call
+to @code{make-record-type} that created the type represented by
+@var{rtd}.
+@end deffn
+
+@deffn {Scheme Procedure} record-type-descriptor record
+Return a record-type descriptor representing the type of the given
+record. That is, for example, if the returned descriptor were passed to
+@code{record-predicate}, the resulting predicate would return a true
+value when passed the given record. Note that it is not necessarily the
+case that the returned descriptor is the one that was passed to
+@code{record-constructor} in the call that created the constructor
+procedure that created the given record.
+@end deffn
+
+@deffn {Scheme Procedure} record-type-name rtd
+Return the type-name associated with the type represented by rtd. The
+returned value is @code{eqv?} to the @var{type-name} argument given in
+the call to @code{make-record-type} that created the type represented by
+@var{rtd}.
+@end deffn
+
+@deffn {Scheme Procedure} record-type-fields rtd
+Return a list of the symbols naming the fields in members of the type
+represented by @var{rtd}. The returned value is @code{equal?} to the
+field-names argument given in the call to @code{make-record-type} that
+created the type represented by @var{rtd}.
+@end deffn
+
+
+@node Structures
+@subsection Structures
+@tpindex Structures
+
+[FIXME: this is pasted in from Tom Lord's original guile.texi and should
+be reviewed]
+
+A @dfn{structure type} is a first class user-defined data type. A
+@dfn{structure} is an instance of a structure type. A structure type is
+itself a structure.
+
+Structures are less abstract and more general than traditional records.
+In fact, in Guile Scheme, records are implemented using structures.
+
+@menu
+* Structure Concepts:: The structure of Structures
+* Structure Layout:: Defining the layout of structure types
+* Structure Basics:: make-, -ref and -set! procedures for structs
+* Vtables:: Accessing type-specific data
+@end menu
+
+@node Structure Concepts
+@subsubsection Structure Concepts
+
+A structure object consists of a handle, structure data, and a vtable.
+The handle is a Scheme value which points to both the vtable and the
+structure's data. Structure data is a dynamically allocated region of
+memory, private to the structure, divided up into typed fields. A
+vtable is another structure used to hold type-specific data. Multiple
+structures can share a common vtable.
+
+When applied to structures, the @code{equal?} predicate
+(@pxref{Equality}) returns @code{#t} if the two structures share a
+common vtable @emph{and} all their fields satisfy @code{equal?}.
+
+Three concepts are key to understanding structures.
+
+@itemize @bullet{}
+@item @dfn{layout specifications}
+
+Layout specifications determine how memory allocated to structures is
+divided up into fields. Programmers must write a layout specification
+whenever a new type of structure is defined.
+
+@item @dfn{structural accessors}
+
+Structure access is by field number. There is only one set of
+accessors common to all structure objects.
+
+@item @dfn{vtables}
+
+Vtables, themselves structures, are first class representations of
+disjoint sub-types of structures in general. In most cases, when a
+new structure is created, programmers must specify a vtable for the
+new structure. Each vtable has a field describing the layout of its
+instances. Vtables can have additional, user-defined fields as well.
+@end itemize
+
+
+
+@node Structure Layout
+@subsubsection Structure Layout
+
+When a structure is created, a region of memory is allocated to hold its
+state. The @dfn{layout} of the structure's type determines how that
+memory is divided into fields.
+
+Each field has a specified type. There are only three types allowed, each
+corresponding to a one letter code. The allowed types are:
+
+@itemize @bullet{}
+@item 'u' -- unprotected
+
+The field holds binary data that is not GC protected.
+
+@item 'p' -- protected
+
+The field holds a Scheme value and is GC protected.
+
+@item 's' -- self
+
+The field holds a Scheme value and is GC protected. When a structure is
+created with this type of field, the field is initialized to refer to
+the structure's own handle. This kind of field is mainly useful when
+mixing Scheme and C code in which the C code may need to compute a
+structure's handle given only the address of its malloc'd data.
+@end itemize
+
+
+Each field also has an associated access protection. There are only
+three kinds of protection, each corresponding to a one letter code.
+The allowed protections are:
+
+@itemize @bullet{}
+@item 'w' -- writable
+
+The field can be read and written.
+
+@item 'r' -- readable
+
+The field can be read, but not written.
+
+@item 'o' -- opaque
+
+The field can be neither read nor written. This kind
+of protection is for fields useful only to built-in routines.
+@end itemize
+
+A layout specification is described by stringing together pairs
+of letters: one to specify a field type and one to specify a field
+protection. For example, a traditional cons pair type object could
+be described as:
+
+@example
+; cons pairs have two writable fields of Scheme data
+"pwpw"
+@end example
+
+A pair object in which the first field is held constant could be:
+
+@example
+"prpw"
+@end example
+
+Binary fields, (fields of type "u"), hold one @dfn{word} each. The
+size of a word is a machine dependent value defined to be equal to the
+value of the C expression: @code{sizeof (long)}.
+
+The last field of a structure layout may specify a tail array.
+A tail array is indicated by capitalizing the field's protection
+code ('W', 'R' or 'O'). A tail-array field is replaced by
+a read-only binary data field containing an array size. The array
+size is determined at the time the structure is created. It is followed
+by a corresponding number of fields of the type specified for the
+tail array. For example, a conventional Scheme vector can be
+described as:
+
+@example
+; A vector is an arbitrary number of writable fields holding Scheme
+; values:
+"pW"
+@end example
+
+In the above example, field 0 contains the size of the vector and
+fields beginning at 1 contain the vector elements.
+
+A kind of tagged vector (a constant tag followed by conventional
+vector elements) might be:
+
+@example
+"prpW"
+@end example
+
+
+Structure layouts are represented by specially interned symbols whose
+name is a string of type and protection codes. To create a new
+structure layout, use this procedure:
+
+@deffn {Scheme Procedure} make-struct-layout fields
+@deffnx {C Function} scm_make_struct_layout (fields)
+Return a new structure layout object.
+
+@var{fields} must be a string made up of pairs of characters
+strung together. The first character of each pair describes a field
+type, the second a field protection. Allowed types are 'p' for
+GC-protected Scheme data, 'u' for unprotected binary data, and 's' for
+a field that points to the structure itself. Allowed protections
+are 'w' for mutable fields, 'r' for read-only fields, and 'o' for opaque
+fields. The last field protection specification may be capitalized to
+indicate that the field is a tail-array.
+@end deffn
+
-@noindent
-@dfn{Uniform arrays} have elements all of the
-same type and occupy less storage than conventional
-arrays. Uniform arrays with a single zero-based dimension
-are also known as @dfn{uniform vectors}. The procedures in
-this section can also be used on conventional arrays, vectors,
-bit-vectors and strings.
-@noindent
-When creating a uniform array, the type of data to be stored
-is indicated with a @var{prototype} argument. The following table
-lists the types available and example prototypes:
+@node Structure Basics
+@subsubsection Structure Basics
-@example
-prototype type printing character
-
-#t boolean (bit-vector) b
-#\a char (string) a
-#\nul byte (integer) y
-'s short (integer) h
-1 unsigned long (integer) u
--1 signed long (integer) e
-'l signed long long (integer) l
-1.0 float (single precision) s
-1/3 double (double precision float) i
-0+i complex (double precision) c
-() conventional vector
-@end example
+This section describes the basic procedures for creating and accessing
+structures.
-Note that with the introduction of exact fractions in Guile 1.8,
-@samp{1/3} here is now a fraction, where previously such an expression
-was a double @samp{0.333@dots{}}. For most normal usages this should
-be source code compatible.
+@deffn {Scheme Procedure} make-struct vtable tail_array_size . init
+@deffnx {C Function} scm_make_struct (vtable, tail_array_size, init)
+Create a new structure.
-Unshared uniform arrays of characters with a single zero-based dimension
-are identical to strings:
+@var{type} must be a vtable structure (@pxref{Vtables}).
-@example
-(make-uniform-array #\a 3) @result{}
-"aaa"
-@end example
+@var{tail-elts} must be a non-negative integer. If the layout
+specification indicated by @var{type} includes a tail-array,
+this is the number of elements allocated to that array.
-@noindent
-Unshared uniform arrays of booleans with a single zero-based dimension
-are identical to @ref{Bit Vectors, bit-vectors}.
+The @var{init1}, @dots{} are optional arguments describing how
+successive fields of the structure should be initialized. Only fields
+with protection 'r' or 'w' can be initialized, except for fields of
+type 's', which are automatically initialized to point to the new
+structure itself; fields with protection 'o' can not be initialized by
+Scheme programs.
-@example
-(make-uniform-array #t 3) @result{}
-#*111
-@end example
+If fewer optional arguments than initializable fields are supplied,
+fields of type 'p' get default value #f while fields of type 'u' are
+initialized to 0.
-@noindent
-Other uniform vectors are written in a form similar to that of vectors,
-except that a single character from the above table is put between
-@code{#} and @code{(}. For example, a uniform vector of signed
-long integers is displayed in the form @code{'#e(3 5 9)}.
+Structs are currently the basic representation for record-like data
+structures in Guile. The plan is to eventually replace them with a
+new representation which will at the same time be easier to use and
+more powerful.
-@deffn {Scheme Procedure} make-uniform-array prototype bound1 bound2 @dots{}
-Create and return a uniform array of type corresponding to
-@var{prototype} that has as many dimensions as there are @var{bound}s
-and fill it with @var{prototype}.
+For more information, see the documentation for @code{make-vtable-vtable}.
@end deffn
-@deffn {Scheme Procedure} array-prototype ra
-@deffnx {C Function} scm_array_prototype (ra)
-Return an object that would produce an array of the same type
-as @var{array}, if used as the @var{prototype} for
-@code{make-uniform-array}.
+@deffn {Scheme Procedure} struct? x
+@deffnx {C Function} scm_struct_p (x)
+Return @code{#t} iff @var{x} is a structure object, else
+@code{#f}.
@end deffn
-@deffn {Scheme Procedure} list->uniform-array ndim prot lst
-@deffnx {Scheme Procedure} list->uniform-vector prot lst
-@deffnx {C Function} scm_list_to_uniform_array (ndim, prot, lst)
-Return a uniform array of the type indicated by prototype
-@var{prot} with elements the same as those of @var{lst}.
-Elements must be of the appropriate type, no coercions are
-done.
-@end deffn
-@deffn {Scheme Procedure} uniform-vector-fill! uve fill
-Store @var{fill} in every element of @var{uve}. The value returned is
-unspecified.
-@end deffn
+@deffn {Scheme Procedure} struct-ref handle pos
+@deffnx {Scheme Procedure} struct-set! struct n value
+@deffnx {C Function} scm_struct_ref (handle, pos)
+@deffnx {C Function} scm_struct_set_x (struct, n, value)
+Access (or modify) the @var{n}th field of @var{struct}.
-@deffn {Scheme Procedure} uniform-vector-length v
-@deffnx {C Function} scm_uniform_vector_length (v)
-Return the number of elements in @var{uve}.
-@end deffn
+If the field is of type 'p', then it can be set to an arbitrary value.
-@deffn {Scheme Procedure} dimensions->uniform-array dims prot [fill]
-@deffnx {Scheme Procedure} make-uniform-vector length prototype [fill]
-@deffnx {C Function} scm_dimensions_to_uniform_array (dims, prot, fill)
-Create and return a uniform array or vector of type
-corresponding to @var{prototype} with dimensions @var{dims} or
-length @var{length}. If @var{fill} is supplied, it's used to
-fill the array, otherwise @var{prototype} is used.
+If the field is of type 'u', then it can only be set to a non-negative
+integer value small enough to fit in one machine word.
@end deffn
-@c Another compiled-closure. -twp
-
-@deffn {Scheme Procedure} uniform-array-read! ra [port_or_fd [start [end]]]
-@deffnx {Scheme Procedure} uniform-vector-read! uve [port-or-fdes] [start] [end]
-@deffnx {C Function} scm_uniform_array_read_x (ra, port_or_fd, start, end)
-Attempt to read all elements of @var{ura}, in lexicographic order, as
-binary objects from @var{port-or-fdes}.
-If an end of file is encountered,
-the objects up to that point are put into @var{ura}
-(starting at the beginning) and the remainder of the array is
-unchanged.
-The optional arguments @var{start} and @var{end} allow
-a specified region of a vector (or linearized array) to be read,
-leaving the remainder of the vector unchanged.
-@code{uniform-array-read!} returns the number of objects read.
-@var{port-or-fdes} may be omitted, in which case it defaults to the value
-returned by @code{(current-input-port)}.
-@end deffn
+@node Vtables
+@subsubsection Vtables
-@deffn {Scheme Procedure} uniform-array-write v [port_or_fd [start [end]]]
-@deffnx {Scheme Procedure} uniform-vector-write uve [port-or-fdes] [start] [end]
-@deffnx {C Function} scm_uniform_array_write (v, port_or_fd, start, end)
-Writes all elements of @var{ura} as binary objects to
-@var{port-or-fdes}.
+Vtables are structures that are used to represent structure types. Each
+vtable contains a layout specification in field
+@code{vtable-index-layout} -- instances of the type are laid out
+according to that specification. Vtables contain additional fields
+which are used only internally to libguile. The variable
+@code{vtable-offset-user} is bound to a field number. Vtable fields
+at that position or greater are user definable.
-The optional arguments @var{start}
-and @var{end} allow
-a specified region of a vector (or linearized array) to be written.
+@deffn {Scheme Procedure} struct-vtable handle
+@deffnx {C Function} scm_struct_vtable (handle)
+Return the vtable structure that describes the type of @var{struct}.
+@end deffn
-The number of objects actually written is returned.
-@var{port-or-fdes} may be
-omitted, in which case it defaults to the value returned by
-@code{(current-output-port)}.
+@deffn {Scheme Procedure} struct-vtable? x
+@deffnx {C Function} scm_struct_vtable_p (x)
+Return @code{#t} iff @var{x} is a vtable structure.
@end deffn
-@node Bit Vectors
-@subsubsection Bit Vectors
+If you have a vtable structure, @code{V}, you can create an instance of
+the type it describes by using @code{(make-struct V ...)}. But where
+does @code{V} itself come from? One possibility is that @code{V} is an
+instance of a user-defined vtable type, @code{V'}, so that @code{V} is
+created by using @code{(make-struct V' ...)}. Another possibility is
+that @code{V} is an instance of the type it itself describes. Vtable
+structures of the second sort are created by this procedure:
-@noindent
-Bit vectors are a specific type of uniform array: an array of booleans
-with a single zero-based index.
+@deffn {Scheme Procedure} make-vtable-vtable user_fields tail_array_size . init
+@deffnx {C Function} scm_make_vtable_vtable (user_fields, tail_array_size, init)
+Return a new, self-describing vtable structure.
-@noindent
-They are displayed as a sequence of @code{0}s and
-@code{1}s prefixed by @code{#*}, e.g.,
+@var{user-fields} is a string describing user defined fields of the
+vtable beginning at index @code{vtable-offset-user}
+(see @code{make-struct-layout}).
-@example
-(make-uniform-vector 8 #t #f) @result{}
-#*00000000
-@end example
+@var{tail-size} specifies the size of the tail-array (if any) of
+this vtable.
-@deffn {Scheme Procedure} bit-count bool bitvector
-@deffnx {C Function} scm_bit_count (bool, bitvector)
-Return a count of how many entries in @var{bitvector} are equal to
-@var{bool}. For example,
+@var{init1}, @dots{} are the optional initializers for the fields of
+the vtable.
-@example
-(bit-count #f #*000111000) @result{} 6
-@end example
-@end deffn
+Vtables have one initializable system field---the struct printer.
+This field comes before the user fields in the initializers passed
+to @code{make-vtable-vtable} and @code{make-struct}, and thus works as
+a third optional argument to @code{make-vtable-vtable} and a fourth to
+@code{make-struct} when creating vtables:
-@deffn {Scheme Procedure} bit-position bool bitvector start
-@deffnx {C Function} scm_bit_position (bool, bitvector, start)
-Return the index of the first occurrance of @var{bool} in
-@var{bitvector}, starting from @var{start}. If there is no @var{bool}
-entry between @var{start} and the end of @var{bitvector}, then return
-@code{#f}. For example,
+If the value is a procedure, it will be called instead of the standard
+printer whenever a struct described by this vtable is printed.
+The procedure will be called with arguments STRUCT and PORT.
-@example
-(bit-position #t #*000101 0) @result{} 3
-(bit-position #f #*0001111 3) @result{} #f
-@end example
-@end deffn
+The structure of a struct is described by a vtable, so the vtable is
+in essence the type of the struct. The vtable is itself a struct with
+a vtable. This could go on forever if it weren't for the
+vtable-vtables which are self-describing vtables, and thus terminate
+the chain.
-@deffn {Scheme Procedure} bit-invert! bitvector
-@deffnx {C Function} scm_bit_invert_x (bitvector)
-Modify @var{bitvector} by replacing each element with its negation.
-@end deffn
+There are several potential ways of using structs, but the standard
+one is to use three kinds of structs, together building up a type
+sub-system: one vtable-vtable working as the root and one or several
+"types", each with a set of "instances". (The vtable-vtable should be
+compared to the class <class> which is the class of itself.)
-@deffn {Scheme Procedure} bit-set*! bitvector uvec bool
-@deffnx {C Function} scm_bit_set_star_x (bitvector, uvec, bool)
-Set entries of @var{bitvector} to @var{bool}, with @var{uvec}
-selecting the entries to change. The return value is unspecified.
+@lisp
+(define ball-root (make-vtable-vtable "pr" 0))
-If @var{uvec} is a bit vector, then those entries where it has
-@code{#t} are the ones in @var{bitvector} which are set to @var{bool}.
-@var{uvec} and @var{bitvector} must be the same length. When
-@var{bool} is @code{#t} it's like @var{uvec} is OR'ed into
-@var{bitvector}. Or when @var{bool} is @code{#f} it can be seen as an
-ANDNOT.
+(define (make-ball-type ball-color)
+ (make-struct ball-root 0
+ (make-struct-layout "pw")
+ (lambda (ball port)
+ (format port "#<a ~A ball owned by ~A>"
+ (color ball)
+ (owner ball)))
+ ball-color))
+(define (color ball) (struct-ref (struct-vtable ball) vtable-offset-user))
+(define (owner ball) (struct-ref ball 0))
-@example
-(define bv #*01000010)
-(bit-set*! bv #*10010001 #t)
-bv
-@result{} #*11010011
-@end example
+(define red (make-ball-type 'red))
+(define green (make-ball-type 'green))
-If @var{uvec} is a uniform vector of unsigned long integers, then
-they're indexes into @var{bitvector} which are set to @var{bool}.
+(define (make-ball type owner) (make-struct type 0 owner))
-@example
-(define bv #*01000010)
-(bit-set*! bv #u(5 2 7) #t)
-bv
-@result{} #*01100111
-@end example
+(define ball (make-ball green 'Nisse))
+ball @result{} #<a green ball owned by Nisse>
+@end lisp
@end deffn
-@deffn {Scheme Procedure} bit-count* bitvector uvec bool
-@deffnx {C Function} scm_bit_count_star (bitvector, uvec, bool)
-Return a count of how many entries in @var{bitvector} are equal to
-@var{bool}, with @var{uvec} selecting the entries to consider.
-
-@var{uvec} is interpreted in the same way as for @code{bit-set*!}
-above. Namely, if @var{uvec} is a bit vector then entries which have
-@code{#t} there are considered in @var{bitvector}. Or if @var{uvec}
-is a uniform vector of unsigned long integers then it's the indexes in
-@var{bitvector} to consider.
+@deffn {Scheme Procedure} struct-vtable-name vtable
+@deffnx {C Function} scm_struct_vtable_name (vtable)
+Return the name of the vtable @var{vtable}.
+@end deffn
-For example,
+@deffn {Scheme Procedure} set-struct-vtable-name! vtable name
+@deffnx {C Function} scm_set_struct_vtable_name_x (vtable, name)
+Set the name of the vtable @var{vtable} to @var{name}.
+@end deffn
-@example
-(bit-count* #*01110111 #*11001101 #t) @result{} 3
-(bit-count* #*01110111 #u(7 0 4) #f) @result{} 2
-@end example
+@deffn {Scheme Procedure} struct-vtable-tag handle
+@deffnx {C Function} scm_struct_vtable_tag (handle)
+Return the vtable tag of the structure @var{handle}.
@end deffn
@subsection Association Lists
@tpindex Association Lists
@tpindex Alist
-
-@cindex Association List
-@cindex Alist
-@cindex Database
+@cindex association List
+@cindex alist
+@cindex aatabase
An association list is a conventional data structure that is often used
to implement simple key-value databases. It consists of a list of
@rnindex assv
@rnindex assoc
-@code{assq}, @code{assv} and @code{assoc} take an alist and a key as
-arguments and return the entry for that key if an entry exists, or
-@code{#f} if there is no entry for that key. Note that, in the cases
-where an entry exists, these procedures return the complete entry, that
-is @code{(KEY . VALUE)}, not just the value.
+@code{assq}, @code{assv} and @code{assoc} find the entry in an alist
+for a given key, and return the @code{(@var{key} . @var{value})} pair.
+@code{assq-ref}, @code{assv-ref} and @code{assoc-ref} do a similar
+lookup, but return just the @var{value}.
@deffn {Scheme Procedure} assq key alist
@deffnx {Scheme Procedure} assv key alist
@deffnx {C Function} scm_assq (key, alist)
@deffnx {C Function} scm_assv (key, alist)
@deffnx {C Function} scm_assoc (key, alist)
-Fetch the entry in @var{alist} that is associated with @var{key}. To
-decide whether the argument @var{key} matches a particular entry in
-@var{alist}, @code{assq} compares keys with @code{eq?}, @code{assv}
-uses @code{eqv?} and @code{assoc} uses @code{equal?}. If @var{key}
-cannot be found in @var{alist} (according to whichever equality
-predicate is in use), then return @code{#f}. These functions
-return the entire alist entry found (i.e. both the key and the value).
-@end deffn
-
-@code{assq-ref}, @code{assv-ref} and @code{assoc-ref}, on the other
-hand, take an alist and a key and return @emph{just the value} for that
-key, if an entry exists. If there is no entry for the specified key,
-these procedures return @code{#f}.
-
-This creates an ambiguity: if the return value is @code{#f}, it means
-either that there is no entry with the specified key, or that there
-@emph{is} an entry for the specified key, with value @code{#f}.
-Consequently, @code{assq-ref} and friends should only be used where it
-is known that an entry exists, or where the ambiguity doesn't matter
-for some other reason.
+Return the first entry in @var{alist} with the given @var{key}. The
+return is the pair @code{(KEY . VALUE)} from @var{alist}. If there's
+no matching entry the return is @code{#f}.
+
+@code{assq} compares keys with @code{eq?}, @code{assv} uses
+@code{eqv?} and @code{assoc} uses @code{equal?}.
+@end deffn
@deffn {Scheme Procedure} assq-ref alist key
@deffnx {Scheme Procedure} assv-ref alist key
@deffnx {C Function} scm_assq_ref (alist, key)
@deffnx {C Function} scm_assv_ref (alist, key)
@deffnx {C Function} scm_assoc_ref (alist, key)
-Like @code{assq}, @code{assv} and @code{assoc}, except that only the
-value associated with @var{key} in @var{alist} is returned. These
-functions are equivalent to
+Return the value from the first entry in @var{alist} with the given
+@var{key}, or @code{#f} if there's no such entry.
-@lisp
-(let ((ent (@var{associator} @var{key} @var{alist})))
- (and ent (cdr ent)))
-@end lisp
+@code{assq-ref} compares keys with @code{eq?}, @code{assv-ref} uses
+@code{eqv?} and @code{assoc-ref} uses @code{equal?}.
-where @var{associator} is one of @code{assq}, @code{assv} or @code{assoc}.
+Notice these functions have the @var{key} argument last, like other
+@code{-ref} functions, but this is opposite to what what @code{assq}
+etc above use.
+
+When the return is @code{#f} it can be either @var{key} not found, or
+an entry which happens to have value @code{#f} in the @code{cdr}. Use
+@code{assq} etc above if you need to differentiate these cases.
@end deffn
+
@node Removing Alist Entries
@subsubsection Removing Alist Entries
@subsection Hash Tables
@tpindex Hash Tables
-@c FIXME::martin: Review me!
-
Hash tables are dictionaries which offer similar functionality as
association lists: They provide a mapping from keys to values. The
difference is that association lists need time linear in the size of
little bit more memory, and that you can not use the normal list
procedures (@pxref{Lists}) for working with them.
+Guile provides two types of hashtables. One is an abstract data type
+that can only be manipulated with the functions in this section. The
+other type is concrete: it uses a normal vector with alists as
+elements. The advantage of the abstract hash tables is that they will
+be automatically resized when they become too full or too empty.
+
@menu
* Hash Table Examples:: Demonstration of hash table usage.
* Hash Table Reference:: Hash table procedure descriptions.
@node Hash Table Examples
@subsubsection Hash Table Examples
-@c FIXME::martin: Review me!
-
For demonstration purposes, this section gives a few usage examples of
some hash table procedures, together with some explanation what they do.
@lisp
(define h (make-hash-table 31))
-(hashq-create-handle! h 'foo "bar")
+;; This is an opaque object
+h
@result{}
-(foo . "bar")
+#<hash-table 0/31>
+
+;; We can also use a vector of alists.
+(define h (make-vector 7 '()))
+
+h
+@result{}
+#(() () () () () () ())
+
+;; Inserting into a hash table can be done with hashq-set!
+(hashq-set! h 'foo "bar")
+@result{}
+"bar"
-(hashq-create-handle! h 'braz "zonk")
+(hashq-set! h 'braz "zonk")
@result{}
-(braz . "zonk")
+"zonk"
+;; Or with hash-create-handle!
(hashq-create-handle! h 'frob #f)
@result{}
(frob . #f)
+
+;; The vector now contains three elements in the alists and the frob
+;; entry is at index (hashq 'frob).
+h
+@result{}
+#(() () () () ((frob . #f) (braz . "zonk")) () ((foo . "bar")))
+
+(hashq 'frob)
+@result{}
+4
+
@end lisp
You can get the value for a given key with the procedure
with any set of functions, but it's imperative that just one set is
then used consistently, or results will be unpredictable.
-@sp 1
Hash tables are implemented as a vector indexed by a hash value formed
from the key, with an association list of key/value pairs for each
bucket in case distinct keys hash together. Direct access to the
pairs in those lists is provided by the @code{-handle-} functions.
+The abstract kind of hash tables hide the vector in an opaque object
+that represents the hash table, while for the concrete kind the vector
+@emph{is} the hashtable.
-When the number of table entries goes above a threshold the vector is
-increased and the entries rehashed, to prevent the bucket lists
-becoming too long and slowing down accesses. When the number of
-entries goes below a threshold the vector is decreased to save space.
+When the number of table entries in an abstract hash table goes above
+a threshold, the vector is made larger and the entries are rehashed,
+to prevent the bucket lists from becoming too long and slowing down
+accesses. When the number of entries goes below a threshold, the
+vector is shrunk to save space.
+
+A abstract hash table is created with @code{make-hash-table}. To
+create a vector that is suitable as a hash table, use
+@code{(make-vector @var{size} '())}, for example.
-@sp 1
For the @code{hashx-} ``extended'' routines, an application supplies a
@var{hash} function producing an integer index like @code{hashq} etc
below, and an @var{assoc} alist search function like @code{assq} etc
@math{@var{size}-1}. Helpful functions for forming a hash value, in
addition to @code{hashq} etc below, include @code{symbol-hash}
(@pxref{Symbol Keys}), @code{string-hash} and @code{string-hash-ci}
-(@pxref{SRFI-13 Comparison}), and @code{char-set-hash} (@pxref{SRFI-14
-Predicates/Comparison}).
-
-Note that currently, unfortunately, there's no @code{hashx-remove!}
-function, which rather limits the usefulness of the @code{hashx-}
-routines.
+(@pxref{String Comparison}), and @code{char-set-hash}
+(@pxref{Character Set Predicates/Comparison}).
@sp 1
@deffn {Scheme Procedure} make-hash-table [size]
-Create a new hash table, with an optional minimum vector @var{size}.
+Create a new abstract hash table object, with an optional minimum
+vector @var{size}.
When @var{size} is given, the table vector will still grow and shrink
automatically, as described above, but with @var{size} as a minimum.
added.
@end deffn
+@deffn {Scheme Procedure} hash-table? obj
+@deffnx {C Function} scm_hash_table_p (obj)
+Return @code{#t} if @var{obj} is a abstract hash table object.
+@end deffn
+
+@deffn {Scheme Procedure} hash-clear! table
+@deffnx {C Function} scm_hash_clear_x (table)
+Remove all items from @var{table} (without triggering a resize).
+@end deffn
+
@deffn {Scheme Procedure} hash-ref table key [dflt]
@deffnx {Scheme Procedure} hashq-ref table key [dflt]
@deffnx {Scheme Procedure} hashv-ref table key [dflt]
@deffn {Scheme Procedure} hash-remove! table key
@deffnx {Scheme Procedure} hashq-remove! table key
@deffnx {Scheme Procedure} hashv-remove! table key
+@deffnx {Scheme Procedure} hashx-remove! hash assoc table key
@deffnx {C Function} scm_hash_remove_x (table, key)
@deffnx {C Function} scm_hashq_remove_x (table, key)
@deffnx {C Function} scm_hashv_remove_x (table, key)
+@deffnx {C Function} scm_hashx_remove_x (hash, assoc, table, key)
Remove any association for @var{key} in the given hash @var{table}.
If @var{key} is not in @var{table} then nothing is done.
@end deffn
HCoop / bpt / guile.git / blobdiff