package parser

import (
	"code.jmug.me/jmug/interpreter-in-go/pkg/token"
)

const (
	_ int = iota
	LOWEST
	EQUALS      // ==
	LESSGREATER // > or <
	SUM         // +
	PRODUCT     // *
	PREFIX      // -X or !X
	CALL        // myFunction(X)
	INDEX       // array[index]
)

var precedences = map[token.TokenType]int{
	token.EQ:       EQUALS,
	token.NOT_EQ:   EQUALS,
	token.GT:       LESSGREATER,
	token.LT:       LESSGREATER,
	token.PLUS:     SUM,
	token.MINUS:    SUM,
	token.ASTERISK: PRODUCT,
	token.SLASH:    PRODUCT,
	token.LPAREN:   CALL,
	token.LBRACKET: INDEX,
}

func (p *Parser) peekPrecedence() int {
	if pr, ok := precedences[p.peekToken.Type]; ok {
		return pr
	}
	return LOWEST
}

func (p *Parser) curPrecedence() int {
	if pr, ok := precedences[p.curToken.Type]; ok {
		return pr
	}
	return LOWEST
}