tom-weatherhead/thaw-grammar

// tom-weatherhead/thaw-grammar/src/languages/lisp/domain-object-model/lisp-symbol.ts

import { ArgumentException } from 'thaw-interpreter-core';

import { SExpressionBase } from './sexpression-base';

const typenameLISPSymbol = 'LISPSymbol';

export function isLISPSymbol(obj: unknown): obj is LISPSymbol {
    const sym = obj as LISPSymbol;

    return typeof sym !== 'undefined' && sym.typename === typenameLISPSymbol;
}

export class LISPSymbol extends SExpressionBase {
    public readonly typename: string = typenameLISPSymbol;
    public readonly value: string;

    constructor(value: string) {
        super();

        if (!value) {
            throw new ArgumentException('LISPSymbol constructor: value is null or empty.', 'value');
        }

        this.value = value;
    }

    public toString(): string {
        return this.value;
    }

    public override isSymbol(): boolean {
        return true;
    }

    public override isEqualTo(other: unknown): boolean {
        return isLISPSymbol(other) && other.value === this.value;
    }
}