jintr/dist/nodes/AssignmentExpression.js

A tiny JavaScript interpreter written in TypeScript.

import BaseJSNode from './BaseJSNode.js';
export default class AssignmentExpression extends BaseJSNode {
    handleMemberExpression(leftNode, rightValue, operation) {
        const obj = this.visitor.visitNode(leftNode.object);
        const prop = this.visitor.visitNode(leftNode.property);
        const currentValue = obj[prop];
        const newValue = operation(currentValue, rightValue);
        return (obj[prop] = newValue);
    }
    handleIdentifier(leftNode, rightValue, operation) {
        const currentValue = this.visitor.visitNode(leftNode);
        const newValue = operation(currentValue, rightValue);
        this.visitor.scope.set(leftNode.name, newValue);
        return this.visitor.scope.get(leftNode.name);
    }
    run() {
        const { operator, left, right } = this.node;
        const rightValue = this.visitor.visitNode(right);
        const operation = AssignmentExpression.operatorMap[operator];
        if (!operation) {
            console.warn('Unhandled operator:', operator);
            return undefined;
        }
        if (left.type === 'MemberExpression') {
            return this.handleMemberExpression(left, rightValue, operation);
        }
        else if (left.type === 'Identifier') {
            return this.handleIdentifier(left, rightValue, operation);
        }
        console.warn('Unhandled left node type:', left.type);
        return undefined;
    }
}
AssignmentExpression.operatorMap = {
    '=': (_, right) => right,
    '+=': (left, right) => left + right,
    '-=': (left, right) => left - right,
    '*=': (left, right) => left * right,
    '/=': (left, right) => left / right,
    '%=': (left, right) => left % right,
    '**=': (left, right) => left ** right,
    '<<=': (left, right) => left << right,
    '>>=': (left, right) => left >> right,
    '>>>=': (left, right) => left >>> right,
    '&=': (left, right) => left & right,
    '^=': (left, right) => left ^ right,
    '|=': (left, right) => left | right
};