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10056 :: Why to_seq not overloaded properly?

• alexeypetrushin (orginal) [2023-04-01T01:10:41+02:00] view original

  This code would fail, because if you define new proc for to_seq old version with iterator would stop working, play. Isn't it supposed to work? I just add one more version of to_seq multiple dispatch function.

  import std/[sequtils, tables]
  
  proc to_seq*[K, V](t: Table[K, V]): seq[(K, V)] =
    for k, v in t: result.add (k, v)
  
  iterator some_iterator*(data: string): string =
    yield "one"
  
  echo to_seq(some_iterator("input"))
  Run

  
  /usercode/in.nim(9, 26) Error: attempting to call routine: 'some_iterator'
    found in.some_iterator(data: string) [iterator declared in /usercode/in.nim(6, 10)]
  Run

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• ElegantBeef (orginal) [2023-04-01T01:16:45+02:00] view original

  This is a limitation of template overloading. To disambiguate the sequtils.toSeq and your proc toSeq the compiler has to semantically analyze some_iterator("input") since there is a procedure overload. First it checks to see the type of some_iterator this is a inline iterator so is invalid inside of a procedure call so it errors that you're attempting to call that routine.

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