Re: [Caml-list] Examples where let rec is undesirable

[Damien Doligez <damien.doligez@inria.fr>]

On 2012-01-05, at 21:46, Gabriel Scherer wrote:

> My argument is the following: when you make a *local* edition to a
> piece of code, shadowing allow you to pick variable name without
> having to know about what's already bound in context.

I agree with Gabriel.  Consider the following expression:

   (let x = 21 in x + x)

Assuming I haven't been so crazy as to redefine (+), is this
a valid expression whose value is 42?

First possible answer: yes
Second possible answer: it depends on the context.

I'd rather go with the first choice, and that means allowing
shadowing.  Consider a camlp4 extension that produces such
expressions.  Does it have to look at the context (including
the "open" statements, functor applications, first-class
modules, etc.) before it can insert this expression into your
code?

-- Damien