ch1-05.y

来自「編譯器的虛擬yacc工具」· Y 代码 · 共 33 行

%{
/*
 * A lexer for the basic grammar to use for recognizing english sentences.
 */
#include <stdio.h>
%}

%token NOUN PRONOUN VERB ADVERB ADJECTIVE PREPOSITION CONJUNCTION END

%%
sentence_list	:	sentence_list sentence END
		|	sentence END
		;

sentence: subject VERB object	{ printf("Sentence is valid.\n"); }
	;

subject:	NOUN
	|	PRONOUN
	;

object:		NOUN
	;
%%

extern FILE *yyin;

yyerror(s)
char *s;
{
    fprintf(stderr, "%s\n", s);
}