Added freshidents to macros

[planetis-m]

There are plenty re-implementations of this all around. It's good to have one in the stdlib.

[disruptek]

Please add a test for genSym artifacts.

[cooldome]

Looks good to me

[ringabout]

Are there some reasons using repr?

[cooldome]

oh yes, it should be $n

[planetis-m]

As disruptek said on irc:

a symbol created with genSym needs to be rendered as ident(repr sym) in order to capture the unique name correctly.

So in the test I added ident($n) or similar will output just "tmp" and redefinition error, whereas with repr you get tmp14141 and works properly.

[cooldome]

AFAIK, with repr you can also get tmp`12312 for gensym which will not compile

[planetis-m]

AFAIK, with repr you can also get tmp`12312 for gensym which will not compile

test passes so it might be fixed

[Clyybber]

Yep, tmp`12312 is fine to use as an identifier once past the parser

[disruptek]

Maybe there's a more correct method than repr, but I am personally fine with its use here.

[Araq]

This is a special case of what I called toUntypedAst, we should have that instead. And also, it should be its own module and part of fusion.

[planetis-m]

Done see link. But collect needs it for a bugfix...

[Araq]

But collect needs it for a bugfix...

Bummer, why though? collect takes untyped arguments.

[planetis-m]

A couple of points:

1. There is a version of this in sugar called freshIdentNodes, used in a couple of places but unexported.
2. For collect it fixes bug sugar.collect can't be used in templates #14332 see PR add collect with infered init, refs #16078 fixes #14332 #16089

[timotheecour]

If the end goal API is toUntypedAst and that is too hard to write right now (nim-lang/fusion#49 was closed), then instead of exposing freshIdentNodes in macros, how about add this to a new private std/private/macroutils, so that other modules in stdlib can at least use it in the meantime?

[stale]

This pull request has been automatically marked as stale because it has not had recent activity. If you think it is still a valid PR, please rebase it on the latest devel; otherwise it will be closed. Thank you for your contributions.