doc/scheme-procedures.texi

   1 @page
   2 @node Procedures and Macros
   3 @chapter Procedures and Macros
   4
   5 @menu
   6 * Lambda::                      Basic procedure creation using lambda.
   7 * Optional Arguments::          Handling keyword, optional and rest arguments.
   8 * Procedure Properties::        Procedure properties and metainformation.
   9 * Procedures with Setters::     Procedures with setters.
  10 * Macros::                      Macros.
  11 @end menu
  12
  13
  14 @node Lambda
  15 @section Lambda: Basic Procedure Creation
  16
  17
  18 @node Optional Arguments
  19 @section Optional Arguments
  20
  21
  22 @node Procedure Properties
  23 @section Procedure Properties and Metainformation
  24
  25 @c docstring begin (texi-doc-string "guile" "procedure-properties")
  26 @deffn primitive procedure-properties proc
  27 Return @var{obj}'s property list.
  28 @end deffn
  29
  30 @c docstring begin (texi-doc-string "guile" "procedure-property")
  31 @deffn primitive procedure-property p k
  32 Return the property of @var{obj} with name @var{key}.
  33 @end deffn
  34
  35 @c docstring begin (texi-doc-string "guile" "set-procedure-properties!")
  36 @deffn primitive set-procedure-properties! proc new_val
  37 Set @var{obj}'s property list to @var{alist}.
  38 @end deffn
  39
  40 @c docstring begin (texi-doc-string "guile" "set-procedure-property!")
  41 @deffn primitive set-procedure-property! p k v
  42 In @var{obj}'s property list, set the property named @var{key} to
  43 @var{value}.
  44 @end deffn
  45
  46 @c docstring begin (texi-doc-string "guile" "procedure-documentation")
  47 @deffn primitive procedure-documentation proc
  48 Return the documentation string associated with @code{proc}.  By
  49 convention, if a procedure contains more than one expression and the
  50 first expression is a string constant, that string is assumed to contain
  51 documentation for that procedure.
  52 @end deffn
  53
  54 @c docstring begin (texi-doc-string "guile" "closure?")
  55 @deffn primitive closure? obj
  56 Return @code{#t} if @var{obj} is a closure.
  57 @end deffn
  58
  59 @c docstring begin (texi-doc-string "guile" "procedure?")
  60 @deffn primitive procedure? obj
  61 Return @code{#t} if @var{obj} is a procedure.
  62 @end deffn
  63
  64 @c docstring begin (texi-doc-string "guile" "thunk?")
  65 @deffn primitive thunk? obj
  66 Return @code{#t} if @var{obj} is a thunk.
  67 @end deffn
  68
  69 @c docstring begin (texi-doc-string "guile" "set-source-properties!")
  70 @deffn primitive set-source-properties! obj plist
  71 Install the association list @var{plist} as the source property
  72 list for @var{obj}.
  73 @end deffn
  74
  75 @c docstring begin (texi-doc-string "guile" "set-source-property!")
  76 @deffn primitive set-source-property! obj key datum
  77 Set the source property of object @var{obj}, which is specified by
  78 @var{key} to @var{datum}.  Normally, the key will be a symbol.
  79 @end deffn
  80
  81 @c docstring begin (texi-doc-string "guile" "source-properties")
  82 @deffn primitive source-properties obj
  83 Return the source property association list of @var{obj}.
  84 @end deffn
  85
  86 @c docstring begin (texi-doc-string "guile" "source-property")
  87
  88 @deffn primitive source-property obj key
  89 Return the source property specified by @var{key} from
  90 @var{obj}'s source property list.
  91 @end deffn
  92
  93
  94 @node Procedures with Setters
  95 @section Procedures with Setters
  96
  97 @c docstring begin (texi-doc-string "guile" "make-procedure-with-setter")
  98 @deffn primitive make-procedure-with-setter procedure setter
  99 Create a new procedure which behaves like @var{procedure}, but
 100 with the associated setter @var{setter}.
 101 @end deffn
 102
 103 @c docstring begin (texi-doc-string "guile" "procedure-with-setter?")
 104 @deffn primitive procedure-with-setter? obj
 105 Return @code{#t} if @var{obj} is a procedure with an
 106 associated setter procedure.
 107 @end deffn
 108
 109 @c docstring begin (texi-doc-string "guile" "procedure")
 110 @deffn primitive procedure proc
 111 Return the procedure of @var{proc}, which must be either a
 112 procedure with setter, or an operator struct.
 113 @end deffn
 114
 115 @c docstring begin (texi-doc-string "guile" "setter")
 116 @deffn primitive setter proc
 117 @end deffn
 118
 119
 120 @node Macros
 121 @section Macros
 122
 123 [FIXME: This needs some more text on the difference between procedures,
 124 macros and memoizing macros.  Also, any definitions listed here should
 125 be double-checked by someone who knows what's going on.  Ask Mikael, Jim
 126 or Aubrey for help. -twp]
 127
 128 @c docstring begin (texi-doc-string "guile" "procedure->syntax")
 129 @deffn primitive procedure->syntax code
 130 Returns a @dfn{macro} which, when a symbol defined to this value
 131 appears as the first symbol in an expression, returns the result
 132 of applying @var{code} to the expression and the environment.
 133 @end deffn
 134
 135 @c docstring begin (texi-doc-string "guile" "procedure->macro")
 136 @deffn primitive procedure->macro code
 137 Returns a @dfn{macro} which, when a symbol defined to this value
 138 appears as the first symbol in an expression, evaluates the result
 139 of applying @var{code} to the expression and the environment.
 140 The value returned from @var{code} which has been passed to
 141 @code{procedure->memoizing-macro} replaces the form passed to
 142 @var{code}.  For example:
 143
 144 @example
 145 (define trace
 146   (procedure->macro
 147    (lambda (x env) `(set! ,(cadr x) (tracef ,(cadr x) ',(cadr x))))))
 148
 149 (trace @i{foo}) @equiv{} (set! @i{foo} (tracef @i{foo} '@i{foo})).
 150 @end example
 151 @end deffn
 152
 153 @c docstring begin (texi-doc-string "guile" "procedure->memoizing-macro")
 154 @deffn primitive procedure->memoizing-macro code
 155 Returns a @dfn{macro} which, when a symbol defined to this value
 156 appears as the first symbol in an expression, evaluates the result
 157 of applying @var{proc} to the expression and the environment.
 158 The value returned from @var{proc} which has been passed to
 159 @code{procedure->memoizing-macro} replaces the form passed to
 160 @var{proc}.  For example:
 161
 162 @example
 163 (define trace
 164   (procedure->macro
 165    (lambda (x env) `(set! ,(cadr x) (tracef ,(cadr x) ',(cadr x))))))
 166
 167 (trace @i{foo}) @equiv{} (set! @i{foo} (tracef @i{foo} '@i{foo})).
 168 @end example
 169 @end deffn
 170
 171 @c docstring begin (texi-doc-string "guile" "macro?")
 172 @deffn primitive macro? obj
 173 Return @code{#t} if @var{obj} is a regular macro, a memoizing macro or a
 174 syntax transformer.
 175 @end deffn
 176
 177 @c ARGFIXME m/obj
 178 @c docstring begin (texi-doc-string "guile" "macro-type")
 179 @deffn primitive macro-type m
 180 Return one of the symbols @code{syntax}, @code{macro} or @code{macro!},
 181 depending on whether @var{obj} is a syntax tranformer, a regular macro,
 182 or a memoizing macro, respectively.  If @var{obj} is not a macro,
 183 @code{#f} is returned.
 184 @end deffn
 185
 186 @c docstring begin (texi-doc-string "guile" "macro-name")
 187 @deffn primitive macro-name m
 188 Return the name of the macro @var{m}.
 189 @end deffn
 190
 191 @c docstring begin (texi-doc-string "guile" "macro-transformer")
 192 @deffn primitive macro-transformer m
 193 Return the transformer of the macro @var{m}.
 194 @end deffn
 195
 196 @c docstring begin (texi-doc-string "guile" "cons-source")
 197 @deffn primitive cons-source xorig x y
 198 Create and return a new pair whose car and cdr are @var{x} and @var{y}.
 199 Any source properties associated with @var{xorig} are also associated
 200 with the new pair.
 201 @end deffn
 202
 203
 204 @c Local Variables:
 205 @c TeX-master: "guile.texi"
 206 @c End: