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8923 :: static in templates not really static?

• bather (orginal) [2022-02-15T23:27:22+01:00] view original

  Hello nimmers,

  I have created a library for calculating crc's and encountered some strange behavior with const computations in the templates (note, rev16b and rev8b works as expected!). I made a minimal example for you guys:

  revxbits.nim

  func rev32b*(b: uint32): uint32 = 0'u32
  Run

  api.nim

  import revxbits
  
  template crcBitwise*(data: string): uint32 =
    const ri = static: 0xFF'u32.rev32b
    #const ri = revxbits.rev32b(0xFF'u32)  ## work!
    0'u32
  Run

  main.nim

  import api
  # api.nim(4, 30) Error: undeclared field: 'rev32b' for type system.uint32
  # [type declared in /x/nim-1.6.4/lib/system/basic_types.nim(11, 3)]
  echo "123456789".crcBitwise()
  Run

  Is this a bug or a feature? 🤔

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• ElegantBeef (orginal) [2022-02-16T03:10:30+01:00] view original

  Typical template dotexpr issue can probably be resolved by doing the following. The issue stems from a.b in a template not being a call so it does not force bind symbols.

  const ri = static: rev32b(0xFF'u32)

  the following also may work, do not recall if it will.

  template crcBitwise*(data: string): uint32 =
    mixin rev32b
    const ri = static: 0xFF'u32.rev32b
  Run

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• PMunch (orginal) [2022-02-16T09:31:15+01:00] view original

  By the way you don't need static here, anything that goes into a const has to be static anyways, so as long as Nim can call the procedure statically, it will.

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