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original commit: 8be171cd621a51eecc2bc04f62139a96540d809f
tokens
Scott Owens 23 years ago
parent 96200c5baf
commit 4ab8d1c1b5
1 changed files with 9 additions and 12 deletions
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21
collects/parser-tools/private-yacc/parser-builder.ss
Unescape Escape View File

@ -4,8 +4,7 @@
(require "input-file-parser.ss"
"table.ss"
"parser-actions.ss"
"grammar.ss"
(lib "pretty.ss"))
"grammar.ss")
(provide build-parser)
@ -48,9 +47,9 @@
(pop-2x (cdr (cdr s)) (sub1 n))
s))))
(lambda (get-token)
(let loop ((stack (list 0)))
(let* ((next (get-token))
(s (car stack))
(let loop ((stack (list 0))
(next (get-token)))
(let* ((s (car stack))
(a (hash-table-get term-sym->index
(if (token? next)
(token-name next)
@ -58,18 +57,16 @@
(action (array2d-ref table s a)))
(cond
((shift? action)
(loop (cons (shift-state action) (cons a stack))))
(loop (cons (shift-state action) (cons a stack)) (get-token)))
((reduce? action)
(display (reduce-prod-num action))
(newline)
(printf "reduce:~a~n" (reduce-prod-num action))
(let* ((A (reduce-lhs-num action))
(new-stack (pop-2x stack (reduce-rhs-length action)))
(goto (array2d-ref table (car new-stack) A)))
(loop (cons goto (cons A new-stack)))))
(loop (cons goto (cons A new-stack)) next)))
((accept? action)
(printf "accept~n")))))))))
(pretty-print parser-code)
(newline)
(printf "accept~n"))
(else (error 'parser)))))))))
(datum->syntax-object
runtime
parser-code

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