Function peek

scripts/libs/esprima.js:1484–1499

()

    }

    function peek() {
        scanning = true;

        skipComment();

        lastIndex = index;
        lastLineNumber = lineNumber;
        lastLineStart = lineStart;

        startIndex = index;
        startLineNumber = lineNumber;
        startLineStart = lineStart;

        lookahead = (typeof extra.tokens !== 'undefined') ? collectToken() : advance();
        scanning = false;
    }

    function Position() {
        this.line = startLineNumber;