tom-weatherhead/thaw-grammar

// tom-weatherhead/thaw-grammar/src/common/domain-object-model/operators.ts

export enum OperatorType {
    // Unknown,
    BinaryNumericOperator,
    BinaryNumericPredicate,
    TypePredicate,
    UnlimitedNumericOperator
}

export class Operators {
    // This class is a Singleton.

    public static getInstance(): Operators {
        if (!Operators.instance) {
            Operators.instance = new Operators();
        }

        return Operators.instance;
    }

    private static instance: Operators;
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    private readonly mapOperatorNameToDetails = new Map<string, [OperatorType, number, any]>();

    private constructor() {
        this.mapOperatorNameToDetails.set('+', [
            OperatorType.UnlimitedNumericOperator,
            -1,
            (a: number, b: number) => a + b
        ]);
        this.mapOperatorNameToDetails.set('-', [
            OperatorType.BinaryNumericOperator,
            2,
            (a: number, b: number) => a - b
        ]);
        this.mapOperatorNameToDetails.set('*', [
            OperatorType.UnlimitedNumericOperator,
            -1,
            (a: number, b: number) => a * b
        ]);
        this.mapOperatorNameToDetails.set('/', [
            OperatorType.BinaryNumericOperator,
            2,
            (a: number, b: number) => Math.floor(a / b)
        ]);
        this.mapOperatorNameToDetails.set('=', [
            OperatorType.BinaryNumericPredicate,
            2,
            (a: number, b: number) => (a === b ? 1 : 0)
        ]);
        this.mapOperatorNameToDetails.set('>', [
            OperatorType.BinaryNumericPredicate,
            2,
            (a: number, b: number) => (a > b ? 1 : 0)
        ]);
        this.mapOperatorNameToDetails.set('<', [
            OperatorType.BinaryNumericPredicate,
            2,
            (a: number, b: number) => (a < b ? 1 : 0)
        ]);
        // this.mapOperatorNameToDetails.set('isNumber?', [OperatorType.TypePredicate, 1, () => ]);
        // this.mapOperatorNameToDetails.set('', [OperatorType., 0, () => ]);
    }

    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    public getOperator(name: string): [OperatorType, number, any] | undefined {
        return this.mapOperatorNameToDetails.get(name);
    }
}