Re: [Emacs-diffs] master 9c4e309: Check that variable lists are actually lists

[Stefan Monnier]

>     'let' and 'let*' document that their first argument has to be a list,
>     but don't check for that; instead, they allow (and silently ignore)
>     other types.  Introduce an explicit type check.

Notice that this may end up breaking currently working code :-(

The way we've generally handled such issues is basically that if the
programmer wants sanity checks, he should byte-compile his code.
This has two corollaries:
- We should make sure that the *byte-compiler* does warn about
  ill-formed code (we currently don't do a great job of that).
- The interpreter can do whatever it wants with ill-formed code and
  doesn't need to go out of its way to detect it.


        Stefan