match.scm

MSYS在windows下模拟了一个类unix的终端

;;   http://www.cs.indiana.edu/scheme-repository/code.match.html
;;
;; or Andrew K. Wright's web page:
;;
;;   http://www.star-lab.com/wright/code.html


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Pattern Matching Syntactic Extensions for Scheme
;;
(define match:version "Version 1.19, Sep 15, 1995")
;;
;; Written by Andrew K. Wright, 1993 ([e-mail]).
;; Adapted from code originally written by Bruce F. Duba, 1991.
;; This package also includes a modified version of Kent Dybvig's
;; define-structure (see Dybvig, R.K., The Scheme Programming Language,
;; Prentice-Hall, NJ, 1987).
;;
;; This macro package extends Scheme with several new expression forms.
;; Following is a brief summary of the new forms.  See the associated
;; LaTeX documentation for a full description of their functionality.
;;
;;
;;         match expressions:
;;
;; exp ::= ...
;;       | (match exp clause ...)
;;       | (match-lambda clause ...)
;;       | (match-lambda* clause ...)
;;       | (match-let ((pat exp) ...) body)
;;       | (match-let* ((pat exp) ...) body)
;;       | (match-letrec ((pat exp) ...) body)
;;       | (match-define pat exp)
;;
;; clause ::= (pat body) | (pat => exp)
;;
;;         patterns:                       matches:
;;
;; pat ::= identifier                      anything, and binds identifier
;;       | _                               anything
;;       | ()                              the empty list
;;       | #t                              #t
;;       | #f                              #f
;;       | string                          a string
;;       | number                          a number
;;       | character                       a character
;;       | 'sexp                           an s-expression
;;       | 'symbol                         a symbol (special case of s-expr)
;;       | (pat_1 ... pat_n)               list of n elements
;;       | (pat_1 ... pat_n . pat_{n+1})   list of n or more
;;       | (pat_1 ... pat_n pat_n+1 ooo)   list of n or more, each element
;;                                           of remainder must match pat_n+1
;;       | #(pat_1 ... pat_n)              vector of n elements
;;       | #(pat_1 ... pat_n pat_n+1 ooo)  vector of n or more, each element
;;                                           of remainder must match pat_n+1
;;       | #&pat                           box