Re: expression and definition context in Scheme

[Maxime Devos]

On 27-08-2022 21:02, Damien Mattei wrote:

in fact just allow 'define that act locally ,see my comment below

I do not know what semantics you want.

    Also, even if (begin ...) and (let () ...) where unified, it would
    be a shame to lose the ability to only have some definitions
    temporarily:

    (define foo 0)

    (let ((foo 0))
      whatever-something-using-the-inner-foo)

    something-using-the-outer-foo-again

i do not propose foo to overwrite the global one

(let ((foo 0))
  (let ((foo 0))
    whatever-something-user-the-inner-foo)
  something-using-the-outer-foo-again)

or

(let ()
  (define foo 0)
  (let ((foo 0))
    whatever-something-user-the-inner-foo)
  something-using-the-outer-foo-again)

In that example, (define foo) might be global, but it might as well have been I did not assume anything about global/local and wrote nothing about overwriting.

, just to allow local define that have a local (in the block) range.

Greetings,
Maxime.

If with 'block' you mean the local (let ...) form, then this is already the case. If not, maybe you are asking for Python-like lexical variables, but you have asked about that in the past -- it's a valid choice, but not Scheme. If something else, you need to be much less vague and much more precise on what you want.

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