67 lines
1.9 KiB
Scheme
67 lines
1.9 KiB
Scheme
;;; nyacc/lang/calc/parser
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;;;
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;;; Copyright (C) 2015,2016 Matthew R. Wette
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;;;
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;;; This program is free software: you can redistribute it and/or modify
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;;; it under the terms of the GNU General Public License as published by
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;;; the Free Software Foundation, either version 3 of the License, or
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;;; (at your option) any later version.
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;;;
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;;; This program is distributed in the hope that it will be useful,
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;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;;; GNU General Public License for more details.
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;;;
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;;; You should have received a copy of the GNU General Public License
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;;; along with this program. If not, see <http://www.gnu.org/licenses/>.
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(define-module (nyacc lang calc parser)
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#:export (calc-parse calc-spec calc-mach)
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#:use-module (nyacc lalr)
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#:use-module (nyacc lex)
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#:use-module (nyacc parse)
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)
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(define calc-spec
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(lalr-spec
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(prec< (left "+" "-") (left "*" "/"))
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(start stmt-list-proxy)
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(grammar
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(stmt-list-proxy
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(stmt-list "\n" ($$ `(stmt-list ,@(reverse $1)))))
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(stmt-list
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(stmt ($$ (list $1)))
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(stmt-list ";" stmt ($$ (cons $3 $1))))
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(stmt
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(ident "=" expr ($$ `(assn-stmt ,$1 ,$3)))
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(expr ($$ `(expr-stmt ,$1)))
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( ($$ '(empty-stmt))))
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(expr
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(expr "+" expr ($$ `(add ,$1 ,$3)))
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(expr "-" expr ($$ `(sub ,$1 ,$3)))
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(expr "*" expr ($$ `(mul ,$1 ,$3)))
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(expr "/" expr ($$ `(div ,$1 ,$3)))
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($fixed ($$ `(fixed ,$1)))
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($float ($$ `(float ,$1)))
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("(" expr ")" ($$ $2)))
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(ident ($ident ($$ `(ident ,$1))))
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)))
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(define calc-mach
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(compact-machine
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(hashify-machine
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(make-lalr-machine calc-spec))))
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(define calc-parse
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(let ((gen-lexer (make-lexer-generator (assq-ref calc-mach 'mtab)
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#:space-chars " \t"))
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(parser (make-lalr-ia-parser calc-mach)))
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(lambda* (#:key (debug #f)) (parser (gen-lexer) #:debug debug))))
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;; --- last line ---
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