match.scm

MSYS在windows下模拟了一个类unix的终端

;;       | ($ struct-name pat_1 ... pat_n) a structure
;;       | (= field pat)                   a field of a structure
;;       | (and pat_1 ... pat_n)           if all of pat_1 thru pat_n match
;;       | (or pat_1 ... pat_n)            if any of pat_1 thru pat_n match
;;       | (not pat_1 ... pat_n)           if all pat_1 thru pat_n don't match
;;       | (? predicate pat_1 ... pat_n)   if predicate true and all of
;;                                           pat_1 thru pat_n match
;;       | (set! identifier)               anything, and binds setter
;;       | (get! identifier)               anything, and binds getter
;;       | `qp                             a quasi-pattern
;;
;; ooo ::= ...                             zero or more
;;       | ___                             zero or more
;;       | ..k                             k or more
;;       | __k                             k or more
;;
;;         quasi-patterns:                 matches:
;;
;; qp  ::= ()                              the empty list
;;       | #t                              #t
;;       | #f                              #f
;;       | string                          a string
;;       | number                          a number
;;       | character                       a character
;;       | identifier                      a symbol
;;       | (qp_1 ... qp_n)                 list of n elements
;;       | (qp_1 ... qp_n . qp_{n+1})      list of n or more
;;       | (qp_1 ... qp_n qp_n+1 ooo)      list of n or more, each element
;;                                           of remainder must match qp_n+1
;;       | #(qp_1 ... qp_n)                vector of n elements
;;       | #(qp_1 ... qp_n qp_n+1 ooo)     vector of n or more, each element
;;                                           of remainder must match qp_n+1
;;       | #&qp                            box
;;       | ,pat                            a pattern
;;       | ,@pat                           a pattern
;;
;; The names (quote, quasiquote, unquote, unquote-splicing, ?, _, $,
;; and, or, not, set!, get!, ..., ___) cannot be used as pattern variables.
;;
;;
;;         structure expressions:
;;
;; exp ::= ...
;;       | (define-structure (id_0 id_1 ... id_n))
;;       | (define-structure (id_0 id_1 ... id_n)
;;                           ((id_{n+1} exp_1) ... (id_{n+m} exp_m)))
;;       | (define-const-structure (id_0 arg_1 ... arg_n))
;;       | (define-const-structure (id_0 arg_1 ... arg_n)
;;                                 ((arg_{n+1} exp_1) ... (arg_{n+m} exp_m)))
;;
;; arg ::= id | (! id) | (@ id)
;;
;;
;; match:error-control controls what code is generated for failed matches.
;; Possible values:
;;  'unspecified - do nothing, ie., evaluate (cond [#f #f])