..< wont work for Types

[juancarlospaco]

type 
  X[A: static[int]] = array[0..A,     int]
  Y[B: static[int]] = array[0..B - 1, int]
  Z[C: static[int]] = array[0..<C,    int] 

Fails with not helpful error message, not consistent with rest of the language:

$ nim c example.nim
  Error: cannot generate code for: C

$

Comment out Z type and it works, new people tend to try to use it because is used in the rest of the language,
I do not understand why it wont work because ..< works for in the VM, div and * works but not ..<,
should be fixed and add a test, or if it can not be fixed improve the error message and document why ..< wont work for types,
and how to do it correctly.

[juancarlospaco]

is this valid syntax ?, I can not find any docs.

[timotheecour]

I'm aware, I know how to fix it (branch pr_fix_6215_array_slice) but it's tricky and caused by fact that compiler hardcodes array type in compiler instead of treating it as a regular type; if it were a regular it'd just work (in fact you can define type array2[N: static int, T] = ...)
also somewhat related to nim-lang#15911

EDIT: duplicate of nim-lang#6215 ?

[juancarlospaco]

So many bugs related, and is labeled as "easy" in that link, is it really easy ?. 🤔

Maybe would be better to documment all the quirks with array explicitly in the manual then...

[timotheecour]

and is labeled as "easy"

no that label has been removed a while ago

Maybe would be better to documment all the quirks with array explicitly in the manual then...

it's fixable though