Method evaluate

src/ast.js:436–489

(scope, lookupFunctions)

  }

  evaluate(scope, lookupFunctions) {
    let left = this.left.evaluate(scope, lookupFunctions);

    switch (this.operation) {
    case '&&': return left && this.right.evaluate(scope, lookupFunctions);
    case '||': return left || this.right.evaluate(scope, lookupFunctions);
    // no default
    }

    let right = this.right.evaluate(scope, lookupFunctions);

    switch (this.operation) {
    case '==' : return left == right; // eslint-disable-line eqeqeq
    case '===': return left === right;
    case '!=' : return left != right; // eslint-disable-line eqeqeq
    case '!==': return left !== right;
    case 'instanceof': return typeof right === 'function' && left instanceof right;
    case 'in': return typeof right === 'object' && right !== null && left in right;
    // no default
    }

    // Null check for the operations.
    if (left === null || right === null || left === undefined || right === undefined) {
      switch (this.operation) {
      case '+':
        if (left !== null && left !== undefined) return left;
        if (right !== null && right !== undefined) return right;
        return 0;
      case '-':
        if (left !== null && left !== undefined) return left;
        if (right !== null && right !== undefined) return 0 - right;
        return 0;
      // no default
      }

      return null;
    }

    switch (this.operation) {
    case '+'  : return autoConvertAdd(left, right);
    case '-'  : return left - right;
    case '*'  : return left * right;
    case '/'  : return left / right;
    case '%'  : return left % right;
    case '<'  : return left < right;
    case '>'  : return left > right;
    case '<=' : return left <= right;
    case '>=' : return left >= right;
    case '^'  : return left ^ right;
    // no default
    }

    throw new Error(`Internal error [${this.operation}] not handled`);
  }

  accept(visitor) {
    return visitor.visitBinary(this);