KennethanCeyer/metric-parser

import { Token } from './token';
import { TokenHelperBase } from './token.helper.base';

export class TokenHelper extends TokenHelperBase {
    public static induceType(token: Token.Token): Token.Type {
        const typeInducers = [
            { predicate: TokenHelper.isUnkown, type: Token.Type.Unknown },
            { predicate: TokenHelper.isWhiteSpace, type: Token.Type.WhiteSpace },
            { predicate: TokenHelper.isOperator, type: Token.Type.Operator },
            { predicate: TokenHelper.isBracket, type: Token.Type.Bracket },
            { predicate: TokenHelper.isDot, type: Token.Type.Dot },
            { predicate: TokenHelper.isValue, type: Token.Type.Value }
        ];

        const extractedToken = typeInducers.find(inducer => inducer.predicate(token));
        return extractedToken
            ? extractedToken.type
            : Token.Type.Unknown;
    }

    public static getPrecedence(token: Token.Token): number {
        return [
            [TokenHelper.isAddition, TokenHelper.isSubtraction],
            [TokenHelper.isMultiplication, TokenHelper.isDivision],
            [TokenHelper.isMod, TokenHelper.isPow],
            [TokenHelper.isBracket]
        ].findIndex(predicate => predicate.some(func => func(token)));
    }

    public static getPrecedenceDiff(source: Token.Token, target: Token.Token): number {
        return TokenHelper.getPrecedence(source) - TokenHelper.getPrecedence(target);
    }
}