// Set implementation
// Matt Perry (mjperry2@uiuc.edu)


#ifndef PARSER_H
#define PARSER_H

#include "element.h"
#include "set.h"

class Parser {
public:
    char* expr;
    enum TokenType {
	END=0,
	NUMBER=1,
	STRING=2,
	SET=3,
	VAR=4,
	ERROR=5,
	ASSIGN=':',
	LP='(',
	RP=')',
	LB='{',
	RB='}',
	COMMA=',',
	UNION='+',	// set ops
	INTERSECTION='^',
	DIFF='-',
	SYMDIFF='/',
	POWERSET='@',
	SUBSET,		// test ops
	PROPER_SUBSET='<',
	EQUAL='=',
	NOTEQUAL,
	INSET='[',
	NOTINSET,
	SIZE='|'
    };
    struct Token {
	TokenType type;
	Element e;
	char var;

	Token() {}
	Token(TokenType t) : type(t) {}
	Token(TokenType t, Element _e) : type(t), e(_e) {}
	Token(Set s) : type(SET), e(s) {}
    };
    Token curtok;
    bool got_error;
public:
    Parser(char* _expr) : expr(_expr), got_error(false) {}

    Token eval();
    Token assign();
    Token testop();
    Token setop();
    Token getelem();
    Token getset();

    Token get_token();

    Token expand(const Token& tok);
    Token error(char*);
};

#endif // parser.h