Internal compiler error for proc alias

[StefanSalewski]

If I remember correctly proc alias with const keyword was possible some years ago. Now with const, let or var we get some different internal errors:

#const
#  myPrint = echo

#let
#  myPuts = system.echo

const # or let or var
  testForMe = assert
testForMe(1 + 1 == 2)

#puts "puts is alias for echo"
#print "print is also alias for echo"

$ nim c t.nim 
Hint: used config file '/home/stefan/Nim/config/nim.cfg' [Conf]
Hint: system [Processing]
Hint: t [Processing]
t.nim(8, 15) Error: internal error: expr(skTemplate); unknown symbol
No stack traceback available
To create a stacktrace, rerun compilation with ./koch temp c <file>
stefan@nuc /tmp/hhh $ nim -v
Nim Compiler Version 0.18.1 [Linux: amd64]
Compiled at 2018-09-05
Copyright (c) 2006-2018 by Andreas Rumpf

git hash: 4aba2981dd47672744191bd17b39bb149f494637
active boot switches: -d:release

[andreaferretti]

It should be possible to do this today as well, but it only makes sense with procs that are non-generic. The generic ones are just "recipes" to instantiate a non-generic one with concrete types, hence it does not make sense to bind it to a runtime variable

[metagn]

It's still possible, it's just that assert is a template and not a proc, if this was going to work templates would have to be compile time values

[StefanSalewski]

Ah yes, I forgot that assert() is a template and not a plain proc. But maybe we can improve the error message -- internal error is a bit confusing, although the source of the error is mentioned: expr(skTemplate)

[narimiran]

But maybe we can improve the error message -- internal error is a bit confusing, although the source of the error is mentioned: expr(skTemplate)

Current devel (0.20.99) produces: Error: VM problem: dest register is not set

[timotheecour]

my PR #11822 fixes this, see test case (works with generics, templates (eg assert), macros (eg echo) etc)

[narimiran]

But maybe we can improve the error message -- internal error is a bit confusing, although the source of the error is mentioned: expr(skTemplate)

Currently with the latest Nim devel, this is the error message: Error: invalid type: 'template (cond: untyped, msg: string)' for const. Did you mean to call the template with '()'?

I consider this an improved error message.