Move typetraits.$ to system. Fixes #5827.

[dom96]

No description provided.

[Araq]

I don't want it in system.nim. Nor do I want people to echo types.

[bluenote10]

Why is that so bad? Imho easily converting types to strings comes in handy

• to-string conversion of generics
• during debugging/development
• in some meta programming use case e.g. when including type information in an error message

My most basic use case looks like this:

import typetraits

type
  Generic[T] = object
    a, b: T

proc `$`*[T](g: Generic[T]): string =
  # A meaningful string representation should encode T in some way.
  # I often want something like this for clarity:
  "Generic[" & $T & "](" & $g.a & ", " & $g.b & ")"

let g = Generic[int](a: 1, b: 2)
echo g # Generic[int](1, 2)

I just went through a bunch of my typetraits imports and they all where because of this.

[kaushalmodi]

I also wondered why the basic foo.type.name needed importing a separate module.

For folks like me who like introspection of the code while developing (habit from Emacs lisp), this is a must have.

Knowing the type of any variable is a requirement for me to help understand Nim better. I now end up importing typetraits everywhere in my notes: https://scripter.co/notes/nim/.

[ghost]

@kaushalmodi why do you use "intToStr" instead of "parseInt" in your notes?

[kaushalmodi]

@Yardanico I use both.. as they are for opposite use cases.. intToStr is for int to string conversion and parseInt is for string to int conversion.

Though I don't know if intToStr is needed at all because $ works just fine.. if foo contains 42 (an int), you can do just $foo instead of importing strutils and then doing intToStr(foo).

[ghost]

@kaushalmodi yes, sorry, I've meant $

[ghost]

@kaushalmodi I think intToStr is needed when you need to add leading zeroes to your number

[krux02]

@Araq can you elaborate on what is so bad for this to be in system.nim? I would vote to have this in system.nim. Often when I debug things, I do echo debugging, and it is just nice when it just works on types, too. Currently I always have to look up for that package that I have to import so that echo on the type just works, and that is bothering me.

[kaushalmodi]

@Yardanico

I think intToStr is needed when you need to add leading zeroes to your number

Let's continue this off-topic discussion here: https://forum.nim-lang.org/t/3874.

[narimiran]

Based on the reactions: everybody is for this practical change, Araq is against it.

What is it gonna be? Merge (after fixing the version number in the comments) or won't fix and close?

[Araq]

What is it gonna be? Merge (after fixing the version number in the comments) or won't fix and close?

I surrender, can be added to system. Once/if the CIs are green, of course.

[dom96]

Rebased, let's see if that helps.

[kaushalmodi]

Fails because of:

�[1m�[31mFAIL: �[36mtbindtypedesc.nim C�[0m
�[1m�[36mTest "tests/metatype/tbindtypedesc.nim" in category "metatype"�[0m
�[1m�[31mFailure: reNimcCrash�[0m
�[33mExpected:�[0m

[narimiran]

Before merging, change it to 0.19.2 or 0.20, depending on when this will be introduced.

[Araq]

The correct version is 0.20 for this.

[Araq]

Makes tests/metatype/tbindtypedesc.nim fail.

[timotheecour]

fixed test failures, addressed comments and revived in #10071