13.6.4.12 Runtime Semantics: ForIn/OfHeadEvaluation ( TDZnames, expr, iterationKind, labelSet)

[Axel Rauschmayer]

https://people.mozilla.org/~jorendorff/es6-draft.html#sec-runtime-semantics-forin-div-ofheadevaluation-tdznames-expr-iterationkind-labelset <https://people.mozilla.org/~jorendorff/es6-draft.html#sec-runtime-semantics-forin-div-ofheadevaluation-tdznames-expr-iterationkind-labelset>

I don’t understand step 2: the temporary environment TDZ is created for step 3. All bindings of TDZ are mutable (even the `const`-declared ones). It looks like TDZ is thrown away afterwards. Why is this step necessary? Why are all bindings mutable?

Thanks!

Axel

-- 
Dr. Axel Rauschmayer
axel at rauschma.de
rauschma.de

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.mozilla.org/pipermail/es-discuss/attachments/20150513/c3310263/attachment.html>