;; (documentation (name plt-match)) ;;
Pattern Matching Syntactic Extensions for Scheme ;; ;; All bugs or questions concerning this software should be directed to ;; Bruce Hauman. The latest version of this software ;; can be obtained from http://sol.cs.wcu.edu/~bhauman/scheme/pattern.php. ;; ;; Special thanks go out to: ;; Robert Bruce Findler for support and bug detection. ;; Doug Orleans for pointing out that pairs should be reused while ;; matching lists. ;; ;; ;; Originally written by Andrew K. Wright, 1993 (wright@research.nj.nec.com) ;; which in turn was adapted from code written by Bruce F. Duba, 1991. ;; ;; This software is in the public domain. Feel free to copy, ;; distribute, and modify this software as desired. No warranties ;; nor guarantees of any kind apply. Please return any improvements ;; or bug fixes to bhauman@cs.wcu.edu so that they may be included ;; in future releases. ;; ;; 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 var ((pat exp) ...) body ...) ;; | (match-let* ((pat exp) ...) body ...) ;; | (match-letrec ((pat exp) ...) body ...) ;; | (match-define pat exp) ;; ;; clause ::= (pat body) | (pat (=> identifier) exp) ;; ;; patterns: matches: ;; ;; pat ::= ;; identifier this binds an identifier if it ;; doesn't conflict with ..k, __k or _ ;; | _ anything ;; | #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) ;; | (var id) allows one to use ..k or _ as ;; identifiers ;; | (list lvp_1 ... lvp_n) list of n elements ;; | (list-rest lvp_1 ... lvp_n pat) an improper list of n elements ;; plus a last element which represents ;; the last cdr of the list ;; | (vector lvp_1 ... lvp_n) vector of n elements ;; | (box pat) box ;; | (struct struct-name (pat_1 ... pat_n)) a structure ;; | (regexp exp) if regular expression exp matches ;; | (regexp exp pat) if result of regexp-match matches pat ;; | (pregexp exp) if pregexp.ss regular expression exp matches ;; | (pregexp exp pat) if result of pregexp-match matches pat ;; | (list-no-order pat ...) matches a list with no regard for ;; the order of the ;; items in the list ;; | (list-no-order pat ... pat_n ooo) pat_n matches the remaining ;; unmatched items ;; | (hash-table (pat_k pat_v) ...) matches the elements of a hash table ;; | (hash-table (pat_k pat_v) ... (pat_kn pat_vn) ooo) ;; pat_kn must match the remaining ;; unmatched key elements ;; pat_vn must match the remaining ;; unmatched value elements ;; | (app field pat) a field of a structure (field is ;; an accessor) ;; Actually field can be any function ;; which can be ;; applied to the data being matched. ;; Ex: (match 5 ((= add1 b) b)) => 6 ;; ;; | (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 ;; ;; lvp ::= pat ooo greedily matches n or more of pat, ;; each element must match pat ;; | pat matches pat ;; ;; 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 ;; | ,@(list lvp . . . lvp-n) ;; | ,@(list-rest lvp-1 . . . lvp-n pat) ;; | ,@`qp qp must evaluate to a list as ;; so that this rule resembles the ;; above two rules ;; ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; (module plt-match mzscheme (provide match match-lambda match-lambda* match-let match-let* match-letrec match-define pregexp-match-with-error exn:misc:match? exn:misc:match-value match-equality-test define-match-expander) (require "private/match/match-internal-func.ss" "private/match/match-expander.ss" "private/match/match-helper.ss" "private/match/match-error.ss" "private/match/test-no-order.ss") )