expression-evaluation/dst/StaticScope.js

Expression Evaluation

export class StaticScope {
    _superscope;
    _subscopes = [];
    _variables = new Map();
    _locals = new Set();
    has(name) {
        return this._variables.has(name) || Boolean(this._superscope?.has(name));
    }
    get(name) {
        return this._variables.get(name) ?? this._superscope?.get(name);
    }
    global(name, variable) {
        this._superscope?.global(name, variable) ?? this._variables.set(name, variable);
        return this;
    }
    local(name, variable) {
        this._variables.set(name, variable);
        this._locals.add(name);
        return this;
    }
    subscope(variables) {
        const scope = new StaticScope();
        scope._superscope = this;
        this._subscopes.push(scope);
        for (const [name, variable] of variables) {
            scope.local(name, variable);
        }
        return scope;
    }
    variables() {
        const variables = {};
        for (const [name, variable] of this._variables) {
            if (!this._locals.has(name)) {
                variables[name] = variable;
            }
        }
        return variables;
    }
}