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793 :: Warning for shadowed symbols?

• mapdog (orginal) [2015-01-25T20:50:24+01:00] view original

  Could we make a compiler switch to warn about imported symbols being shadowed?

  import mod # contents: var bar: int = 1
  var bar int = 2
  Run

  Warning: shadowed symbol:

  var bar: int shadows symbol in mod

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• def (orginal) [2015-01-25T21:01:43+01:00] view original

  This one happens a lot:

  proc foo: int =
    var result = 10
    inc result
  Run

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• LeuGim (orginal) [2015-01-25T21:05:42+01:00] view original

  Usually when a programmer declares some symbol in his module he wants to use just that symbol instead of imported ones, when unqualified. And if still introduce such a warning, then a per-declaration {.nowarning.} pragma is needed.

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• mapdog (orginal) [2015-01-26T05:23:32+01:00] view original

  Its just that Nims default import everything can cause you to overlook something. A warning would let you rename or exclude from import.

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• Araq (orginal) [2015-01-26T09:20:14+01:00] view original

  • result is a special case and a very common newbie gotcha, so we will warn or even error about that.
  • That said, a warning for shadowing has been tried and only found to be annoying. Thing is, shadowing is an idiom in Nim:

  proc doSomething(x: string) =
    let x = x.normalize
    # shadowing prevents us to use the non-normalized 'x' here:
    echo x
  Run

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• mapdog (orginal) [2015-01-26T11:01:32+01:00] view original

  I originally meant specifically shawdowed imports, but didn't write that.

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