racket/collects/scribblings/reference/match-grammar.rkt
2011-07-02 10:37:53 -04:00

65 lines
3.8 KiB
Racket

#lang scheme/base
(require "match-parse.rkt")
(provide match-grammar)
(define grammar "
pat ::= id @match anything, bind identifier
| (VAR id) @match anything, bind identifier
| _ @match anything
| literal @match literal
| (QUOTE datum) @match equal% value
| (LIST lvp ...) @match sequence of lvps
| (LIST-REST lvp ... pat) @match lvps consed onto a pat
| (LIST-NO-ORDER pat ...) @match pats in any order
| (LIST-NO-ORDER pat ... lvp) @match pats in any order
| (VECTOR lvp ...) @match vector of pats
| (HASH-TABLE (pat pat) ...) @match hash table
| (HASH-TABLE (pat pat) ...+ ooo) @match hash table
| (CONS pat pat) @match pair of pats
| (MCONS pat pat) @match mutable pair of pats
| (BOX pat) @match boxed pat
| (struct-id pat ...) @match struct-id instance
| (STRUCT struct-id (pat ...)) @match struct-id instance
| (REGEXP rx-expr) @match string
| (REGEXP rx-expr pat) @match string, result with pat
| (PREGEXP px-expr) @match string
| (PREGEXP px-expr pat ) @match string, result with pat
| (AND pat ...) @match when all pats match
| (OR pat ...) @match when any pat match
| (NOT pat ...) @match when no pat matches
| (APP expr pat) @match (expr value) to pat
| (? expr pat ...) @match if (expr value) and pats
| (QUASIQUOTE qp) @match a quasipattern
| derived-pattern @match using extension
literal ::= #t @match true
| #f @match false
| string @match equal% string
| bytes @match equal% byte string
| number @match equal% number
| char @match equal% character
| keyword @match equal% keyword
| regexp literal @match equal% regexp literal
| pregexp literal @match equal% pregexp literal
lvp ::= (code:line pat ooo) @greedily match pat instances
| pat @match pat
qp ::= literal @match literal
| id @match symbol
| (qp ...) @match sequences of qps
| (qp ... . qp) @match qps ending qp
| (qp ooo . qp) @match qps beginning with repeated qp
| #(qp ...) @match vector of qps
| #&qp @match boxed qp
| ,pat @match pat
| ,@(LIST lvp ...) @match lvps, spliced
| ,@(LIST-REST lvp ... pat) @match lvps plus pat, spliced
| ,@'qp @match list-matching qp, spliced
ooo ::= *** @zero or more; *** is literal
| ___ @zero or more
| ..K @K or more
| __K @K or more
")
(define match-grammar
(parse-match-grammar grammar))