@c -*-texinfo-*-
@c This is part of the GNU Guile Reference Manual.
-@c Copyright (C) 1996, 1997, 2000, 2001, 2002, 2003, 2004, 2006, 2007,
-@c 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
+@c Copyright (C) 1996, 1997, 2000-2004, 2006-2014
+@c Free Software Foundation, Inc.
@c See the file guile.texi for copying conditions.
@node Simple Data Types
@tpindex Booleans
The two boolean values are @code{#t} for true and @code{#f} for false.
+They can also be written as @code{#true} and @code{#false}, as per R7RS.
Boolean values are returned by predicate procedures, such as the general
equality predicates @code{eq?}, @code{eqv?} and @code{equal?}
written as @code{3.0} with an explicit decimal-point is inexact, but
it is also an integer. The functions @code{integer?} and
@code{scm_is_integer} report true for such a number, but the functions
-@code{scm_is_signed_integer} and @code{scm_is_unsigned_integer} only
+@code{exact-integer?}, @code{scm_is_exact_integer},
+@code{scm_is_signed_integer}, and @code{scm_is_unsigned_integer} only
allow exact integers and thus report false. Likewise, the conversion
functions like @code{scm_to_signed_integer} only accept exact
integers.
@deffn {Scheme Procedure} integer? x
@deffnx {C Function} scm_integer_p (x)
Return @code{#t} if @var{x} is an exact or inexact integer number, else
-@code{#f}.
+return @code{#f}.
@lisp
(integer? 487)
@result{} #f
(integer? +inf.0)
-@result{} #t
+@result{} #f
@end lisp
@end deffn
This is equivalent to @code{scm_is_true (scm_integer_p (x))}.
@end deftypefn
+@deffn {Scheme Procedure} exact-integer? x
+@deffnx {C Function} scm_exact_integer_p (x)
+Return @code{#t} if @var{x} is an exact integer number, else
+return @code{#f}.
+
+@lisp
+(exact-integer? 37)
+@result{} #t
+
+(exact-integer? 3.0)
+@result{} #f
+@end lisp
+@end deffn
+
+@deftypefn {C Function} int scm_is_exact_integer (SCM x)
+This is equivalent to @code{scm_is_true (scm_exact_integer_p (x))}.
+@end deftypefn
+
@defvr {C Type} scm_t_int8
@defvrx {C Type} scm_t_uint8
@defvrx {C Type} scm_t_int16
@deftypefnx {C Function} scm_t_uint64 scm_to_uint64 (SCM x)
@deftypefnx {C Function} scm_t_intmax scm_to_intmax (SCM x)
@deftypefnx {C Function} scm_t_uintmax scm_to_uintmax (SCM x)
+@deftypefnx {C Function} scm_t_intptr scm_to_intptr_t (SCM x)
+@deftypefnx {C Function} scm_t_uintptr scm_to_uintptr_t (SCM x)
When @var{x} represents an exact integer that fits into the indicated
C type, return that integer. Else signal an error, either a
`wrong-type' error when @var{x} is not an exact integer, or an
@deftypefnx {C Function} SCM scm_from_uint64 (scm_t_uint64 x)
@deftypefnx {C Function} SCM scm_from_intmax (scm_t_intmax x)
@deftypefnx {C Function} SCM scm_from_uintmax (scm_t_uintmax x)
+@deftypefnx {C Function} SCM scm_from_intptr_t (scm_t_intptr x)
+@deftypefnx {C Function} SCM scm_from_uintptr_t (scm_t_uintptr x)
Return the @code{SCM} value that represents the integer @var{x}.
These functions will always succeed and will always return an exact
number.
The short name for the ``delete'' character (code point U+007F) is
@code{#\del}.
+The R7RS name for the ``escape'' character (code point U+001B) is
+@code{#\escape}.
+
There are also a few alternative names left over for compatibility with
previous versions of Guile.
@code{scm_t_wchar} is a signed, 32-bit integer.
@end deftypefn
+Characters also have ``formal names'', which are defined by Unicode.
+These names can be accessed in Guile from the @code{(ice-9 unicode)}
+module:
+
+@example
+(use-modules (ice-9 unicode))
+@end example
+
+@deffn {Scheme Procedure} char->formal-name chr
+Return the formal all-upper-case Unicode name of @var{ch},
+as a string, or @code{#f} if the character has no name.
+@end deffn
+
+@deffn {Scheme Procedure} formal-name->char name
+Return the character whose formal all-upper-case Unicode name is
+@var{name}, or @code{#f} if no such character is known.
+@end deffn
+
@node Character Sets
@subsection Character Sets
characters enclosed in double quotes (@nicode{"}).
Backslash is an escape character and can be used to insert the following
-special characters. @nicode{\"} and @nicode{\\} are R5RS standard, the
-next seven are R6RS standard --- notice they follow C syntax --- and the
-remaining four are Guile extensions.
+special characters. @nicode{\"} and @nicode{\\} are R5RS standard,
+@nicode{\|} is R7RS standard, the next seven are R6RS standard ---
+notice they follow C syntax --- and the remaining four are Guile
+extensions.
@table @asis
@item @nicode{\\}
Double quote character (an unescaped @nicode{"} is otherwise the end
of the string).
+@item @nicode{\|}
+Vertical bar character.
+
@item @nicode{\a}
Bell character (ASCII 7).
@item @nicode{\0}
NUL character (ASCII 0).
+@item @nicode{\(}
+Open parenthesis. This is intended for use at the beginning of lines in
+multiline strings to avoid confusing Emacs lisp modes.
+
@item @nicode{\} followed by newline (ASCII 10)
Nothing. This way if @nicode{\} is the last character in a line, the
string will continue with the first character from the next line,
@node Symbol Read Syntax
@subsubsection Extended Read Syntax for Symbols
+@cindex r7rs-symbols
+
The read syntax for a symbol is a sequence of letters, digits, and
@dfn{extended alphabetic characters}, beginning with a character that
cannot begin a number. In addition, the special cases of @code{+},
widespread usage of it is discouraged because it is not portable and not
very readable.
+Alternatively, if you enable the @code{r7rs-symbols} read option (see
+@pxref{Scheme Read}), you can write arbitrary symbols using the same
+notation used for strings, except delimited by vertical bars instead of
+double quotes.
+
+@example
+|foo bar|
+|\x3BB; is a greek lambda|
+|\| is a vertical bar|
+@end example
+
+Note that there's also an @code{r7rs-symbols} print option
+(@pxref{Scheme Write}). To enable the use of this notation, evaluate
+one or both of the following expressions:
+
+@example
+(read-enable 'r7rs-symbols)
+(print-enable 'r7rs-symbols)
+@end example
+
@node Symbol Uninterned
@subsubsection Uninterned Symbols
HCoop / bpt / guile.git / blobdiff