mutable iterator cannot yield named tuples

[disruptek]

This does not compile and I think it should.

iterator pairs*[K, V](group: Group[K, V]): (K, V) =
  for key, value in group.table.pairs:
    yield (key: key, val: value)

iterator mpairs*[K, V](group: Group[K, V]): (K, var V) =
  for key, value in group.table.mpairs:
    yield (key: key, val: value)  # compiler error
    yield (key, value)            # compiles

Nim Compiler Version 1.0.4 [Linux: amd64]
Compiled at 2019-12-16
Copyright (c) 2006-2019 by Andreas Rumpf

git hash: 97e0ce3c75c9348226ea1fcdfc601c6fbe5c0e75
active boot switches: -d:danger

[disruptek]

Looking at this more closely...

iterator mpairs*[K, V](group: var Group[K, V]): tuple[key: K, val: var V] =
  for key, value in group.table.mpairs:
    yield (key, value)

This syntax produces a codegen error:

/home/adavidoff/.cache/nim/nimph_r/@mnimph@sdependency.nim.c: In function ‘addedRequirements__NqsTCaB70tMWsL58CQq9czQ’:
/home/adavidoff/.cache/nim/nimph_r/@mnimph@sdependency.nim.c:3671:24: error: ‘*dependencies’ is a pointer; did you mean to use ‘->’?
     T4_ = &dependencies->Sup;
                        ^~
                        ->

This one produces a compiler error:

iterator mpairs*[K, V](group: Group[K, V]): tuple[key: K, val: var V] =
  for key, value in group.table.mpairs:
    yield (key: key, val: value)

/home/adavidoff/git/nimph/src/nimph/group.nim(129, 25) Error: expression has no address

This one compiles:

iterator mpairs*[K, V](group: Group[K, V]): tuple[key: K, val: var V] =
  for key, value in group.table.mpairs:
    yield (key, value)

[cooldome]

I will make a fix for no address issue