* doc/ref/match.texi: Document match-lambda, match-lambda*, match-let, match-let* and match-letrec. --- doc/ref/match.texi | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 63 insertions(+), 2 deletions(-)
diff --git a/doc/ref/match.texi b/doc/ref/match.texi index 12e3814ae..4d85fe3f9 100644 --- a/doc/ref/match.texi +++ b/doc/ref/match.texi @@ -213,8 +213,69 @@ any @var{person} whose second slot is a promise that evaluates to a one-element list containing a @var{person} whose first slot is @code{"Bob"}. -Please refer to the @code{ice-9/match.upstream.scm} file in your Guile -installation for more details. +The @code{(ice-9 match)} module also provides the following convenient +syntactic sugar macros wrapping around @code{match}. + +@deffn {Scheme Syntax} match-lambda exp clause1 clause2 @dots{} +Create a procedure of one argument that matches its argument against +each clause. + +@example +(match-lambda clause1 clause2 @dots{}) +@equiv{} +(lambda (arg) (match arg clause1 clause2 @dots{})) +@end example +@end deffn + +@deffn {Scheme Syntax} match-lambda* exp clause1 clause2 @dots{} +Create a procedure of any number of arguments that matches its argument +list against each clause. + +Equivalent to +@example +(match-lambda* clause1 clause2 @dots{}) +@equiv{} +(lambda args (match args clause1 clause2 @dots{})) +@end example +@end deffn + +@deffn {Scheme Syntax} match-let ((variable expression) @dots{}) body +Match each variable to the corresponding expression, and evaluate the +body with all matched variables in scope. Raise an error if any of the +expressions fail to match. @code{match-let} is analogous to named let +and can also be used for recursive functions which match on their +arguments as in @code{match-lambda*}. + +@example +(match-let (((x y) (list 1 2)) + ((a b) (list 3 4))) + (list a b x y)) +@result{} +(3 4 1 2) +@end example +@end deffn + +@deffn {Scheme Syntax} match-let* ((variable expression) @dots{}) body +Similar to @code{match-let}, but analogously to @code{let*}, match and +bind the variables in sequence, with preceding match variables in scope. + +@example +(match-let* (((x y) (list 1 2)) + ((a b) (list x 4))) + (list a b x y)) +@equiv{} +(match-let (((x y) (list 1 2))) + (match-let (((a b) (list x 4))) + (list a b x y))) +@result{} +(1 4 1 2) +@end example +@end deffn + +@deffn {Scheme Syntax} match-letrec ((variable expression) @dots{}) body +Similar to @code{match-let}, but analogously to @code{letrec}, match and +bind the variables with all match variables in scope. +@end deffn Guile also comes with a pattern matcher specifically tailored to SXML trees, @xref{sxml-match}. -- 2.15.1