%{

#include <stdio.h>
#include <string.h>
#include <pcre.h>

#define OVECCOUNT 3

int yylex (void);
void yyerror (char const *);

int regex_cmp(char* s, char* r);

%}

%union {
	int b;	
	int n;
	char* str;
}

%token <str> CONST
%token <str> REGEX
%token <n> NUM
%left EQ NEQ GE LE GT LT RE NRE
%left '|' '&' '^'
%left '!'
%type <b> boo

%%
input:	/* empty */
	| input line
;

line:	'\n'
	| boo '\n'	 	{ printf("%s\n",$1?"true":"false"); }
	| error '\n' 		{ yyerrok; }
;

boo:	 CONST EQ CONST 	{ $$ = ! strcmp($1, $3); }
	| CONST NEQ CONST 	{ $$ = !! strcmp($1, $3); }
	| CONST RE REGEX	{ $$ = regex_cmp($1,$3) >= 0 }
	| CONST NRE REGEX	{ $$ = regex_cmp($1,$3) < 0 }
	| NUM EQ NUM		{ $$ = $1 == $3 }
	| NUM NEQ NUM		{ $$ = $1 != $3 }
	| NUM GE NUM		{ $$ = $1 >= $3 }
	| NUM LE NUM		{ $$ = $1 <= $3 }
	| NUM GT NUM		{ $$ = $1 > $3 }
	| NUM LT NUM		{ $$ = $1 < $3 }
	| boo '|' boo 		{ $$ = $1 || $3 }
	| boo '&' boo		{ $$ = $1 && $3 }
	| boo '^' boo		{ $$ = ($1 || $3) && !($1 && $3) }
	| '!' boo		{ $$ = ! $2 }
;

;
%%

#include <ctype.h>
#include <stdlib.h>

#define BUFSIZE 4096

int 
regex_cmp(char* s, char* r)
{
	pcre *brum;
	int erroroffset;
	const char* error;
	int ovector[OVECCOUNT];
	
	brum=pcre_compile(r,0,&error,&erroroffset,NULL);
	if (!brum)
		return -1;
	
	int res=pcre_exec(brum,NULL,s,strlen(s),0,0,ovector,OVECCOUNT);
	
	pcre_free(brum);

	return res;
}

char*
get_string_out(char delim)
{
	int last = delim; 
	int i = 0;
	char* s;
	int c;

	if (!(s = malloc(BUFSIZE))){
		puts("Low memory");
		exit(0);
	}

	while ((c = getchar()) != delim || last == '\\'){
		if (last=='\\' && c != delim)
			s[i-1] = c;
		else {		
			s[i] = c;
			i++;
		}
		last = c;
		if (i >= BUFSIZE-1)
			break;
	}	
	s[i] = '\0';

	return s;
}

int
yylex(void)
{

	int c, last;
	
	while ((c = getchar ()) == ' ' || c == '\t');
	
	if (c == '"'){
		last = '"';
		yylval.str = get_string_out('"');
		return CONST;	
	}

	if (c == '\''){
		last = '\'';
		yylval.str = get_string_out('\'');
		return CONST;	
	}

	if (c == '/'){
		last = '/';
		yylval.str = get_string_out('/');	
		return REGEX;	
	}

	if (isdigit(c)){
		ungetc(c,stdin);
		scanf("%d",&yylval.n);
		return NUM;
	}

	if (c == '!'){
		if ((c = getchar ()) == '=')
			return NEQ;
		else if (c == '~')
			return NRE;
		else
			ungetc(c,stdin);
	}

	if (c == '<'){
		if ((c = getchar ()) == '=')
			return LE;
		else {
			ungetc(c,stdin);
			return LT;
		}
	}

	if (c == '>'){
		if ((c = getchar ()) == '=')
			return GE;
		else {
			ungetc(c,stdin);
			return GT;
		}
	}

	if (c == '='){
		if ((c = getchar ()) == '=')
			return EQ;
		else
			ungetc(c,stdin);
	}

	if (c == '~'){
		if ((c = getchar ()) == '~')
			return RE;
		else
			ungetc(c,stdin);
	}
	
	if (c == EOF)
		return 0;
	
	return c;
}

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

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