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|
/* C code supplied at the beginning of the file. */
%{
#include <stdio.h>
#include <string.h>
extern int yylexlinenum; /* these are in YYlex */
extern char *yytext; /* current token */
%}
/* Keywords and reserved words begin here. */
%union{ /* this is the data union */
char name[128]; /* names */
}
/*-------------------- the reserved words -----------------------------*/
%token PERIOD
%token NEWLINE
%token POSITIONAL
%token VERB
%token ADVERB
%token PROPER_NOUN
%token NOUN
%token DECLARATIVE
%token CONDITIONAL
%type <name> declarative
%type <name> verb_phrase
%type <name> noun_phrase
%type <name> position_phrase
%type <name> adverb
%type <name> POSITIONAL VERB ADVERB PROPER_NOUN
%type <name> NOUN DECLARATIVE CONDITIONAL
%%
sentence_list : sentence
| sentence_list NEWLINE sentence
;
sentence : verb_phrase noun_phrase position_phrase adverb period
{
printf("I understand that sentence.\n");
printf("VP = %s \n",$1);
printf("NP = %s \n",$2);
printf("PP = %s \n",$3);
printf("AD = %s \n",$4);
}
| { yyerror("That's a strange sentence !!"); }
;
position_phrase : POSITIONAL declarative PROPER_NOUN
{
sprintf($$,"%s %s %s",$1,$2,$3);
}
| /* empty */ { strcpy($$,""); }
;
verb_phrase : VERB { strcpy($$,$1); strcat($$," "); }
| adverb VERB
{
sprintf($$,"%s %s",$1,$2);
}
;
adverb : ADVERB { strcpy($$,$1); }
| /* empty */ { strcpy($$,""); }
;
noun_phrase : DECLARATIVE NOUN
{
sprintf($$,"%s %s",$1,$2);
}
| CONDITIONAL declarative NOUN
{
sprintf($$,"%s %s %s",$1,$2,$3);
}
| NOUN { strcpy($$,$1); strcat($$," "); }
;
declarative : DECLARATIVE { strcpy($$,$1); }
| /* empty */ { strcpy($$,""); }
;
period : /* empty */
| PERIOD
;
%%
/* Supplied main() and yyerror() functions. */
int main(int argc, char *argv[])
{
yyparse(); /* parse the file */
return(0);
}
int yyerror(char *message)
{
extern FILE *yyout;
fprintf(yyout,"\nError at line %5d. (%s) \n",
yylexlinenum,message);
}
|
