Method let

rhino/src/main/java/org/mozilla/javascript/Parser.java:2558–2595

(boolean isStatement, int pos)

    // have to pass in 'let' kwd position to compute kid offsets properly
    private AstNode let(boolean isStatement, int pos) throws IOException {
        LetNode pn = new LetNode(pos);
        pn.setLineColumnNumber(lineNumber(), columnNumber());
        if (mustMatchToken(Token.LP, "msg.no.paren.after.let", true)) pn.setLp(ts.tokenBeg - pos);
        pushScope(pn);
        try {
            VariableDeclaration vars = variables(Token.LET, ts.tokenBeg, isStatement);
            pn.setVariables(vars);
            if (mustMatchToken(Token.RP, "msg.no.paren.let", true)) {
                pn.setRp(ts.tokenBeg - pos);
            }
            if (isStatement && peekToken() == Token.LC) {
                // let statement
                consumeToken();
                int beg = ts.tokenBeg; // position stmt at LC
                AstNode stmt = statements();
                mustMatchToken(Token.RC, "msg.no.curly.let", true);
                stmt.setLength(ts.tokenEnd - beg);
                pn.setLength(ts.tokenEnd - pos);
                pn.setBody(stmt);
                pn.setType(Token.LET);
            } else {
                // let expression
                AstNode expr = expr(false);
                pn.setLength(getNodeEnd(expr) - pos);
                pn.setBody(expr);
                if (isStatement) {
                    // let expression in statement context
                    ExpressionStatement es = new ExpressionStatement(pn, !insideFunctionBody());
                    es.setLineColumnNumber(pn.getLineno(), pn.getColumn());
                    return es;
                }
            }
        } finally {
            popScope();
        }
        return pn;
    }

    void defineSymbol(int declType, String name) {
        defineSymbol(declType, name, false);