private scanPunctuator()

in src/scanner.ts [571:656]

• 70 lines of code
• 45 McCabe index (conditional complexity)

    private scanPunctuator(): RawToken {
        const start = this.index;

        // Check for most common single-character punctuators.
        let str = this.source[this.index];
        switch (str) {

            case '(':
            case '{':
                if (str === '{') {
                    this.curlyStack.push('{');
                }
                ++this.index;
                break;

            case '.':
                ++this.index;
                if (this.source[this.index] === '.' && this.source[this.index + 1] === '.') {
                    // Spread operator: ...
                    this.index += 2;
                    str = '...';
                }
                break;

            case '}':
                ++this.index;
                this.curlyStack.pop();
                break;
            case ')':
            case ';':
            case ',':
            case '[':
            case ']':
            case ':':
            case '?':
            case '~':
                ++this.index;
                break;

            default:
                // 4-character punctuator.
                str = this.source.substr(this.index, 4);
                if (str === '>>>=') {
                    this.index += 4;
                } else {

                    // 3-character punctuators.
                    str = str.substr(0, 3);
                    if (str === '===' || str === '!==' || str === '>>>' ||
                        str === '<<=' || str === '>>=' || str === '**=') {
                        this.index += 3;
                    } else {

                        // 2-character punctuators.
                        str = str.substr(0, 2);
                        if (str === '&&' || str === '||' || str === '==' || str === '!=' ||
                            str === '+=' || str === '-=' || str === '*=' || str === '/=' ||
                            str === '++' || str === '--' || str === '<<' || str === '>>' ||
                            str === '&=' || str === '|=' || str === '^=' || str === '%=' ||
                            str === '<=' || str === '>=' || str === '=>' || str === '**') {
                            this.index += 2;
                        } else {

                            // 1-character punctuators.
                            str = this.source[this.index];
                            if ('<>=!+-*%&|^/'.indexOf(str) >= 0) {
                                ++this.index;
                            }
                        }
                    }
                }
        }

        if (this.index === start) {
            this.throwUnexpectedToken();
        }

        return {
            type: Token.Punctuator,
            value: str,
            lineNumber: this.lineNumber,
            lineStart: this.lineStart,
            start: start,
            end: this.index
        };
    }