CMinilan.y

Parser for minilanguage CMinilan

// Author: Overxfl0w13 //
%token BEGGIN END PLUS MINUS MULT DIV PRINT EOS LP RP INTEGER FLOAT VARIABLE
%left GT LT EQ
%left '+' '-'
%left '*' '/'

%{
	#include <stdio.h>
	int yylex(void);
	void yyerror(char *);
	float result;
	int sym[26];
%}

%%

program:
	BEGGIN instructions END		{ printf("PARSER:: program <== BEGIN instructions END\n"); }
	;

instructions:
	instructions instruction	{ printf("PARSER:: instructions <== instructions instruction\n"); }
	| instruction				{ printf("PARSER:: instructions <== instruction\n"); }
	;

instruction:
	sentence EOS				{ printf("PARSER:: instruction <== sentence EOS\n"); }
	;

sentence:
	printSentence				{ printf("PARSER:: sentence <== printSentence\n"); }
	| VARIABLE '=' arithExpr	{ 
									printf("PARSER:: VARIABLE <== arithExpr\n");
									sym[$1] = $3;
								}
	;

printSentence:
	PRINT LP arithExpr RP		{ 
									printf("PARSER:: printSentence <== PRINT LP arithExpr RP\n"); 
								}
	;

arithExpr:
	arithExpr PLUS term			{ 
									printf("PARSER:: arithExpt <== arithExpr PLUS term\n"); 
									result = $1 + $3;
									printf("Result: %f\n",result);
								}
	| arithExpr MINUS term		{ 
									printf("PARSER:: program <== BEGIN instructions END\n"); 
									result = $1 - $3;
									printf("Result: %f\n",result);
								}
	| term						{ printf("PARSER:: program <== BEGIN instructions END\n"); }
	;

term:
	term MULT factor			{ 
									printf("PARSER:: term <== term MULT factor\n"); 
									result = $1 * $3;
									printf("Result: %f\n",result);
								}
	| term DIV factor			{ 
									printf("PARSER:: term <== term DIV factor\n"); 
									result = $1 / $3;
									printf("Result: %f\n",result);
								}
	| factor					{ printf("PARSER:: term <== factor\n"); }
	;

factor:
	INTEGER						{ printf("PARSER:: factor <== NUMBER\n");   }
	| FLOAT						{ printf("PARSER:: factor <== FLOAT\n");	}
	| VARIABLE					{ printf("PARSER:: factor <== VARIABLE\n"); }
	| LP arithExpr RP			{ printf("PARSER:: factor <== LP arithExpr RP\n");	}
	| PLUS LP arithExpr RP		{ printf("PARSER:: factor <== PLUS LP arithExpr RP\n");	}
	| MINUS LP arithExpr RP		{ printf("PARSER:: factor <== MINUS LP arithExpr RP\n");	}
	| PLUS INTEGER				{ printf("PARSER:: factor <== PLUS INTEGER\n");	}
	| PLUS FLOAT				{ printf("PARSER:: factor <== PLUS FLOAT\n");	}
	| MINUS INTEGER				{ printf("PARSER:: factor <== MINUS INTEGER\n");	}
	| MINUS FLOAT				{ printf("PARSER:: factor <== MINUS FLOAT\n");	}
	
	;
%%

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

int main(void){
	yyparse();
	return 0;
}