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(define-module (parser driver)
#:use-module (ice-9 match)
#:export (tokens->ast))
(define (die)
(error "syntax error"))
(define (tokens->ast tokens)
(match tokens
((func ...)
(list 'prog (function func)))
(_ (die))))
(define (function tokens)
(match tokens
(('int (? string? id) 'left-paren 'void 'right-paren 'open-brace stmt ... 'close-brace)
(list 'func id (statement stmt)))
(_ (die))))
(define (statement tokens)
(match tokens
(('return expr ... 'semi-colon)
(list 'stmt (expression expr)))
(_ (die))))
(define (expression tokens)
(match tokens
(((? integer? int))
int)
(((or 'neg 'not) expr ...)
(list 'expr (car tokens) (expression expr)))
(('left-paren expr ... 'right-paren)
(expression expr))
(_ (die))))
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