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5570 :: Can proc/method name be used as parameter

• javinyang (orginal) [2019-11-21T05:42:28+01:00] view original

  Obviously the following is wrong:

  
  proc testCallback[T](callback: proc(this: T) {.closure, gcsafe, locks: 0.}) = callback()
  
  type TestType = object
    discard
  
  proc helloNim(this: TestType) = echo "Hello, Nim!"
  
  proc testProc(this: TestType) =
    testCallback(this.helloNim)  #Want to callback
  Run

  Must be nested?

  
  type TestType = object
    discard
  
  proc helloNim(this: TestType) = echo "Hello, Nim!"
  
  proc testProc(this: TestType) =
    var hm = proc () = this.helloNim()
    testCallback(hm)
  
  var t: TestType
  t.testProc()
  Run

  some cumbersome

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• demotomohiro (orginal) [2019-11-21T06:45:25+01:00] view original

  You can pass a procedure without making anonymous Procs if procedure type match.

  type TestType = object
  
  proc testCallback(callback: proc(this: TestType) {.closure, gcsafe, locks: 0.}, this: TestType) = this.callback()
  
  proc helloNim(this: TestType) = echo "Hello, Nim!"
  
  proc testProc(this: TestType) =
    testCallback(helloNim, this)
  
  var t: TestType
  t.testProc()
  Run

  or

  proc testCallback(callback: proc() {.closure, gcsafe, locks: 0.}) = callback()
  
  proc helloNim() = echo "Hello, Nim!"
  
  testCallback(helloNim)
  Run

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