931d214b69
Moved match implementation to new mzlib/private/match directory. Implement keyword arguments to define-match-expander. svn: r3943
158 lines
7.1 KiB
Scheme
158 lines
7.1 KiB
Scheme
;; (documentation (name plt-match))
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;; <pre>Pattern Matching Syntactic Extensions for Scheme
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;;
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;; All bugs or questions concerning this software should be directed to
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;; Bruce Hauman <bhauman@cs.wcu.edu>. The latest version of this software
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;; can be obtained from http://sol.cs.wcu.edu/~bhauman/scheme/pattern.php.
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;;
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;; Special thanks go out to:
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;; Robert Bruce Findler for support and bug detection.
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;; Doug Orleans for pointing out that pairs should be reused while
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;; matching lists.
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;;
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;;
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;; Originally written by Andrew K. Wright, 1993 (wright@research.nj.nec.com)
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;; which in turn was adapted from code written by Bruce F. Duba, 1991.
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;;
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;; This software is in the public domain. Feel free to copy,
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;; distribute, and modify this software as desired. No warranties
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;; nor guarantees of any kind apply. Please return any improvements
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;; or bug fixes to bhauman@cs.wcu.edu so that they may be included
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;; in future releases.
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;;
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;; This macro package extends Scheme with several new expression forms.
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;; Following is a brief summary of the new forms. See the associated
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;; LaTeX documentation for a full description of their functionality.
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;;
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;;
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;; match expressions:
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;;
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;; exp ::= ...
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;; | (match exp clause ...)
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;; | (match-lambda clause ...)
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;; | (match-lambda* clause ...)
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;; | (match-let ((pat exp) ...) body ...)
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;; | (match-let var ((pat exp) ...) body ...)
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;; | (match-let* ((pat exp) ...) body ...)
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;; | (match-letrec ((pat exp) ...) body ...)
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;; | (match-define pat exp)
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;;
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;; clause ::= (pat body) | (pat (=> identifier) exp)
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;;
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;; patterns: matches:
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;;
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;; pat ::=
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;; identifier this binds an identifier if it
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;; doesn't conflict with ..k, __k or _
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;; | _ anything
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;; | #t #t
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;; | #f #f
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;; | string a string
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;; | number a number
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;; | character a character
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;; | 'sexp an s-expression
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;; | 'symbol a symbol (special case of s-expr)
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;; | (var id) allows one to use ..k or _ as
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;; identifiers
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;; | (list lvp_1 ... lvp_n) list of n elements
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;; | (list-rest lvp_1 ... lvp_n pat) an improper list of n elements
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;; plus a last element which represents
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;; the last cdr of the list
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;; | (vector lvp_1 ... lvp_n) vector of n elements
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;; | (box pat) box
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;; | (struct struct-name (pat_1 ... pat_n)) a structure
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;; | (regexp exp) if regular expression exp matches
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;; | (regexp exp pat) if result of regexp-match matches pat
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;; | (pregexp exp) if pregexp.ss regular expression exp matches
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;; | (pregexp exp pat) if result of pregexp-match matches pat
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;; | (list-no-order pat ...) matches a list with no regard for
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;; the order of the
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;; items in the list
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;; | (list-no-order pat ... pat_n ooo) pat_n matches the remaining
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;; unmatched items
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;; | (hash-table (pat_k pat_v) ...) matches the elements of a hash table
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;; | (hash-table (pat_k pat_v) ... (pat_kn pat_vn) ooo)
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;; pat_kn must match the remaining
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;; unmatched key elements
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;; pat_vn must match the remaining
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;; unmatched value elements
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;; | (app field pat) a field of a structure (field is
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;; an accessor)
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;; Actually field can be any function
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;; which can be
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;; applied to the data being matched.
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;; Ex: (match 5 ((= add1 b) b)) => 6
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;;
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;; | (and pat_1 ... pat_n) if all of pat_1 thru pat_n match
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;; | (or pat_1 ... pat_n) if any of pat_1 thru pat_n match
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;; | (not pat_1 ... pat_n) if all pat_1 thru pat_n don't match
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;; | (? predicate pat_1 ... pat_n) if predicate true and all of
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;; pat_1 thru pat_n match
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;; | (set! identifier) anything, and binds setter
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;; | (get! identifier) anything, and binds getter
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;; | `qp a quasi-pattern
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;;
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;; lvp ::= pat ooo greedily matches n or more of pat,
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;; each element must match pat
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;; | pat matches pat
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;;
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;; ooo ::= ... zero or more
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;; | ___ zero or more
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;; | ..k k or more
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;; | __k k or more
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;;
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;; quasi-patterns: matches:
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;;
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;; qp ::= () the empty list
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;; | #t #t
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;; | #f #f
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;; | string a string
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;; | number a number
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;; | character a character
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;; | identifier a symbol
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;; | (qp_1 ... qp_n) list of n elements
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;; | (qp_1 ... qp_n . qp_{n+1}) list of n or more
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;; | (qp_1 ... qp_n qp_n+1 ooo) list of n or more, each element
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;; of remainder must match qp_n+1
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;; | #(qp_1 ... qp_n) vector of n elements
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;; | #(qp_1 ... qp_n qp_n+1 ooo) vector of n or more, each element
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;; of remainder must match qp_n+1
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;; | #&qp box
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;; | ,pat a pattern
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;; | ,@(list lvp . . . lvp-n)
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;; | ,@(list-rest lvp-1 . . . lvp-n pat)
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;; | ,@`qp qp must evaluate to a list as
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;; so that this rule resembles the
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;; above two rules
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;;
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;;
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;;
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(module plt-match mzscheme
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(provide
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match
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match-lambda
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match-lambda*
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match-let
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match-let*
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match-letrec
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match-define
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pregexp-match-with-error
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exn:misc:match?
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exn:misc:match-value
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match-equality-test
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define-match-expander)
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(require "private/match/match-internal-func.ss"
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"private/match/match-expander.ss"
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"private/match/match-helper.ss"
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"private/match/match-error.ss"
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"private/match/test-no-order.ss")
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)
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