On 2/17/12 7:18 AM, Andrew Pennebaker wrote:
ssylvan, as a Lisper I would be in favor of having fn name(args) ...
desugar to let name = fn(args) ... where fn is essentially lambda.
I am not in favor of removing named fn items for several reasons.
1. I like that named functions do not inherit their environment. I find
that for long functions I typically only want one or two variables from
the environment, and inheriting more than that is inviting bugs, as
those other variables are not meant to be used. This could admittedly
be addressed by requiring explicit capture clauses.
2. In addition, the order of closure construction is very significant in
Rust, particularly when you do things like move data into a closure.
But declarations like "fn foo()" do not look like side-effecting
statements, although they would be. Also, item decl order is generally
insignificant in Rust, but this would no longer be the case.
3. Finally, the issue of mutually recursive functions would become quite
annoying. As I understand it, this proposal would mean that functions
inherit the names that appear before their declaration, making it hard
to write a mutually recursive function declaration. If you decide to
inherit all names from the parent, then it becomes quite challenging to
know whether all variables that might be used have been initialized.
You end up needing a `let rec` form or something like that.
No doubt these issues can be addressed, but just making "fn foo(x,y)"
sugar for "let foo = {|x, y| ...}" will not be very usable by itself (imo).
Niko
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