Re: How do I pass a variable defined in a wrapping let, to a lambda?

[Eric Abrahamsen]

Steinar Bang <sb@dod.no> writes:

> I have been trying to write a restclient.el[1] result function that can be
> used to save the body of a GET result to a file[2].
>
> My first attempt didn't work[3].
>
> I tried to look at an existing result function that actually worked[4],
> and I finally figured it out: the final form of that function is a
> lambda!
>
> So it was probably that lambda that was run to create the result?
>
> I rewrote my example code to this[5].
>
> But it still didn't work.  And the reason it didn't work is that
> filename didn't have a value set.
>
> If I replace the filename variable with a text constant[6], then the
> function works.
>
> But as far as I can tell, the function in[4] uses variables defined in
> the wrapping (let) in the lambda...?
>
> So why is that working but my filename failing?

They've got a lexical-binding cookie at the top of the file, but you don't! :)