48 lines
2.4 KiB
Scheme
48 lines
2.4 KiB
Scheme
#lang scheme/base
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(require (lib "scribblings/reference/match-parse.ss"))
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(provide match-grammar)
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(define grammar "
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pat ::= id @match anything, bind identifier
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| _ @match anything
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| literal @match literal
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| 'datum @match equal% datum
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| (lvp ...) @match sequence of lvps
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| (lvp ... . pat) @match lvps consed onto a pat
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| #(lvp ...) @match vector of pats
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| #&pat @match boxed pat
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| ($ struct-id pat ...) @match struct-id instance
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| (AND pat ...) @match when all pats match
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| (OR pat ...) @match when any pat match
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| (NOT pat ...) @match when no pat match
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| (= expr pat) @match (expr value) to pat
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| (? pred-expr pat ...) @match if (expr value) and pats
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| (set! identifier) @match anything, bind as setter
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| (get! identifier) @match anything, bind as getter
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| `qp @match quasipattern
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literal ::= #t @match true
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| #f @match false
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| string @match equal% string
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| number @match equal% number
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| character @match equal% character
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lvp ::= pat ooo @greedily match pat instances
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| pat @match pat
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ooo ::= *** @zero or more; *** is literal
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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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qp ::= literal @match literal
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| id @match equal% symbol
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| (qp ...) @match sequences of qps
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| (qp ... . qp) @match sequence of qps consed onto a qp
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| (qp ... qp ooo) @match qps consed onto a repeated qp
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| #(qp ...) @match vector of qps
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| #&qp @match boxed qp
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| ,pat @match pat
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| ,@pat @match pat, spliced
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")
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(define match-grammar
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(parse-match-grammar grammar))
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