getTypeImplEx: A version of `getTypeImpl` that returns the "expressed" type after transformations.

gistfile1.txt

import std / macros
type
  Vec[N: static[int], T] = object
    arr: array[N, T]
  Vec4[T] = Vec[4, T]
  Vec4f = Vec4[float32]

var a: Vec4f

proc isTypeDesc(n: NimNode): bool =
  var t = n.getType
  t.kind == nnkBracketExpr and t[0].kind == nnkSym and t[0].strVal == "typeDesc"

proc getTypeImplEx(n: NimNode): NimNode = 
  if n.isTypeDesc():
    n.getTypeImpl[1].getTypeImpl
  else:
    n.getTypeImpl

macro test(t: typed) =
  expectKind t, nnkSym
  echo t.getImpl.treeRepr

  var tyImpl = t.getTypeImplEx()
  echo tyImpl.treeRepr

test(a)
test(Vec4f)