import { Parser } from '../parse'
import { Token } from '../../tokenizer/token'
import { IExpression } from '../expression'
import { GenericOperatorExpression } from '../expressions/genericOperator'
import { IInfixParselet } from './infix'

export class NotEqualsOperator implements IInfixParselet {
	constructor(public precedence = 0) {}

	parse(parser: Parser, leftExpression: IExpression, token: Token) {
		if (parser.match('EQUALS')) {
			return new GenericOperatorExpression(
				leftExpression,
				parser.parseExpression(this.precedence),
				'!=',
				(leftExpression: IExpression, rightExpression: IExpression) =>
					leftExpression.eval() !== rightExpression.eval()
			)
		} else {
			throw new Error(`! was used as a binary operator`)
		}
	}
}