Method _parseExpression

source/python.js:1078–1483

(minPrecedence, terminal, tuple)

                return null;
            }
            _parseExpression(minPrecedence, terminal, tuple) {
                minPrecedence = minPrecedence || -1;
                const terminalSet = new Set(terminal);
                const stack = [];
                for (;;) {
                    let position = this._position();
                    let node = null;
                    const token = this._tokenizer.peek();
                    if (stack.length === 1 && terminalSet.has(token.value)) {
                        break;
                    }
                    const precedence = ast._Parser._precedence[token.value];
                    if (precedence) {
                        if (precedence >= minPrecedence) {
                            this._tokenizer.read();
                            if (token.value === 'not' && this._tokenizer.accept('id', 'in')) {
                                token.value = 'not in';
                            } else if (token.value === 'is' && this._tokenizer.accept('id', 'not')) {
                                token.value = 'is not';
                            }
                            if (stack.length > 0) {
                                let op = null;
                                switch (token.value) {
                                    case '+':  op = new ast.Add(); break;
                                    case '-':  op = new ast.Sub(); break;
                                    case '*':  op = new ast.Mult(); break;
                                    case '/':  op = new ast.Div(); break;
                                    case '//': op = new ast.FloorDiv(); break;
                                    case '**': op = new ast.Pow(); break;
                                    case '@':  op = new ast.MatMult(); break;
                                    case '&':  op = new ast.BitAnd(); break;
                                    case '^':  op = new ast.BitXor(); break;
                                    case '|':  op = new ast.BitOr(); break;
                                    case '%':  op = new ast.Mod(); break;
                                    case '>>': op = new ast.RShift(); break;
                                    case '<<': op = new ast.LShift(); break;
                                    default: break;
                                }
                                if (op) {
                                    const left = stack.pop();
                                    const right = this._parseExpression(precedence, terminal, tuple === true);
                                    node = new ast.BinOp(left, op, right);
                                } else {
                                    switch (token.value) {
                                        case '==': op = new ast.Eq(); break;
                                        case '!=': op = new ast.NotEq(); break;
                                        case '>=': op = new ast.GtE(); break;
                                        case '<=': op = new ast.LtE(); break;
                                        case '<':  op = new ast.Lt(); break;
                                        case '>':  op = new ast.Gt(); break;
                                        case 'is': op = new ast.Is(); break;
                                        case 'is not': op = new ast.IsNot(); break;
                                        case 'in': op = new ast.In(); break;
                                        case 'not in': op = new ast.NotIn(); break;
                                        default: break;
                                    }
                                    const left = stack.pop();
                                    const comparator = this._parseExpression(precedence, ['for', 'if'], tuple === true);