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10060 :: How do I test if varaible is a type of proc?

• singularity-desu (orginal) [2023-04-01T14:41:26+02:00] view original

  I want to check if variable is a specific type of proc. For example:

  proc test(a: int): int = discard
  
  echo test is proc (a: int): int
  Run

  However this code counter-intuitively returns false. So how do I check this?

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• singularity-desu (orginal) [2023-04-01T14:44:12+02:00] view original

  This is somehow very broken, take a look:

  proc test(a: int): int = discard
  
  echo typeof(test)
  echo test is typeof(test)
  echo test is proc (a: int): int{.noSideEffect, gcsafe, locks: 0.}
  Run

  This prints out:

  proc (a: int): int{.noSideEffect, gcsafe, locks: 0.}
  true
  false
  Run

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• Araq (orginal) [2023-04-01T14:51:47+02:00] view original

  Please report it on github.

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• sls1005 (orginal) [2023-04-01T17:34:36+02:00] view original

  Calling conversions didn't match.

  proc test(a: int): int = discard
  
  echo test is (proc (a: int): int {.nimcall.}) #true
  Run

  Normal procs that's not variables are default to {.nimcall.}, but as a variable type, proc is default to {.closure.}.

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• sls1005 (orginal) [2023-04-02T07:51:26+02:00] view original

  To explain it:

  proc f(): int = discard #default to `{.nimcall.}`
  
  echo f is proc(): int {.closure.} #false
  echo f is proc(): int {.nimcall.} #true
  echo f is proc(): int             #false; `proc(): int` is default to `{.closure.}` when used as a type.
  Run

  Anyway I don't think it's a bug, as it follows the definition of the language. The problem is that such rules are not strightforward.

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