tom-weatherhead/thaw-grammar

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

import { ifDefinedThenElse } from 'thaw-common-utilities.ts';

import { ArgumentException /*, EvaluationException */ } from 'thaw-interpreter-core';

// import { ArgumentNullException } from '../exceptions/argument-null-exception';
// import { KeyNotFoundException } from '../exceptions/key-not-found-exception';

import { IEnvironmentFrame } from './environment-frame';
import { IExpression } from './iexpression';
import { IGlobalInfo } from './iglobal-info';

const typenameVariableT = 'Variable<T>';

export function isVariableT<T>(obj: unknown): obj is Variable<T> {
    const otherVariable = obj as Variable<T>;

    return typeof otherVariable !== 'undefined' && otherVariable.typename === typenameVariableT;
}

export interface IVariable<T> extends IExpression<T> {
    readonly name: string;
    readonly line: number;
    readonly column: number;
}

export class Variable<T> implements IVariable<T> {
    // , IConvertibleToGraph
    public readonly typename: string = typenameVariableT;

    constructor(
        public readonly name: string,
        public readonly line = 0,
        public readonly column = 0
    ) {
        if (!this.name) {
            throw new ArgumentException('A Variable cannot have an empty name', 'name');
        }

        // Console.WriteLine("Creating a Variable named '{0}'.", name);

        // if (name.StartsWith("Inference")) {
        //     throw new Exception(string.Format("Error: Creating variable named '{0}'.", name));
        // }
    }

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

    public evaluate(
        globalInfo: IGlobalInfo<T>,
        localEnvironment?: IEnvironmentFrame<T>,
        // eslint-disable-next-line @typescript-eslint/no-unused-vars
        options?: unknown
    ): T {
        if (this.name === 'stackdump') {
            if (typeof localEnvironment === 'undefined') {
                console.log(
                    'Variable<T>.evaluate() : On stackdump: localEnvironment is undefined.'
                );
            }

            ifDefinedThenElse(localEnvironment, globalInfo.globalEnvironment).stackDump();

            return globalInfo.trueValue;
        }

        // try {
        return ifDefinedThenElse(localEnvironment, globalInfo.globalEnvironment).lookup(this);
        // } catch (KeyNotFoundException) {
        //     throw new EvaluationException(
        //         `Variable<T>.Evaluate() : No value found for variable ${this.name}`,
        //         this.line,
        //         this.column
        //     );
        // }
    }
}