{.procvar.} still used despite being the default and not documented

[timotheecour]

{.procvar.} is still being used but is not documented:
The only doc is from ast.nim (but it doesn't end up in docs):

sfProcvar,        # proc can be passed to a proc var

and yet, apparently procvar is now on by default according to #2172 (comment)

proposal

• remove remaining procvar annotations
• remove wProcVar
• remove sfProcvar (?)
• remove all remaining mentions of procvar

[Clyybber]

procvar is default and effectively gone. No need to document it. See #2172

[timotheecour]

effectively gone but stil 94 mentions in nim sources; the fact that it's still used yet un-documented makes it even more confusing for users encountering this pragma, who wonder what it does, etc; either we get rid of it (at very least in stdlib), or (easy fix), we document that it's a noop

[Clyybber]

Then it should be removed, and not documented, but I see you edited your issue to reflect that :)

[kaushalmodi]

I stumbled across this same issue today:

• https://irclogs.nim-lang.org/15-05-2020.html#15:00:09
• https://irclogs.nim-lang.org/15-05-2020.html#17:43:17

All I wanted to do was attempt to send a PR for unicode.nim, but then I saw the {.procvar.} pragma sprinkled for some procs and not for others. That led me down the rabbit hole and finally to this issue.

/cc @Araq

[kaushalmodi]

#14359 fixes this partially.

[kaushalmodi]

@Araq Thanks for merging that PR.

Now grepping for '\bprocvar\b' in the Nim repo returns these:

tests/errmsgs/tcannot_capture_builtin.nim
2:errormsg: "'+' cannot be passed to a procvar"

compiler/sempass2.nim
488:    localError(conf, n.info, "'$1' cannot be passed to a procvar" % n.sym.name.s)

compiler/wordrecg.nim
137:    "compilerproc", "core", "procvar", "base", "used",

doc/manual_experimental.rst
1765:However, one of the overloaded methods calls a procvar which is

doc/manual.rst
3230:  let procVar = (proc(x: string))(p)
3231:  procVar("a")
7319:indirectly; so the ``thread`` pragma implies ``procvar``.

I am not sure how to remove or modify procvar references in those.

Apart those those, grepping just 'procvar' returns a lot more hits like sfProcVar, wProcVar and others, which I don't know how to deal with.

[timotheecour]

well looks like procvar distinction still matters after all; I just retried #2172 (comment) and still relevant:

proc `+`*(x: int): int {.magic: "UnaryPlusI", noSideEffect.}

proc foo[T](a: T,
          b: T,
          f: proc(x: T, y: T): T): T =
  return f(a,b)

let a = 11
let b = 10

let z = foo(a,b,`+`)

echo z

Error: '+' cannot be passed to a procvar
  let z = foo(a,b,`+`)

[Clyybber]

Not related to procvar though, but to the fact that + is a builtin. The error message just needs to be updated.