tom-weatherhead/thaw-grammar

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

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

import { IExpression } from '../../../common/domain-object-model/iexpression';
import { INumber } from './inumber';
import { ISExpression } from './isexpression';
import { SExpressionBase } from './sexpression-base';

const typenameIntegerLiteral = 'IntegerLiteral';

export function isIntegerLiteral(obj: unknown): obj is IntegerLiteral {
    const otherIntegerLiteral = obj as IntegerLiteral;

    return (
        typeof otherIntegerLiteral !== 'undefined' &&
        otherIntegerLiteral.typename === typenameIntegerLiteral
    );
}

export class IntegerLiteral extends SExpressionBase implements INumber {
    // , IConvertibleToGraph
    public readonly typename: string = typenameIntegerLiteral;
    public readonly value: number;

    constructor(value: unknown) {
        super();

        // HACK ThAW 2020-01-06 : The value in an IntegerLiteral can be int or float.
        // In the future, we will need to properly support FloatLiterals
        // and distinguish them from IntegerLiterals.

        if (typeof value !== 'number') {
            throw new ArgumentException(
                `IntegerLiteral constructor: typeof value '${value}' is not 'number'; it is '${typeof value}'.`,
                'value'
            );
        } else if (Number.isNaN(value)) {
            throw new ArgumentException(
                'IntegerLiteral constructor: value is not a number (NaN).',
                'value'
            );
            // } else if (Math.floor(value) !== value) {
            // throw new ArgumentException(`IntegerLiteral constructor: value '${value}' is not an integer.`, 'value');
        }

        this.value = value as number;
    }

    public toString(): string {
        // Do not allow the output to be formatted as scientific notation.

        return `${this.value}`;
    }

    public toInteger(): number {
        return this.value;
    }

    public toDouble(): number {
        return this.value;
    }

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

    public convertToGraph(): IExpression<ISExpression> {
        return this;
    }

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