proctypes

## it _is_ possible to add procs to a type with a macro pragma
## first attempt in dataclass.nim, but i can do it a bit cleaner now
## instead of that hacky helper template we can do it with nnkStmtListType
## should check out nnkBlockType as well, not sure what that's about
## with this one, both the inner and outer type have the _same_ _name_
## i think they're the same type!
## the outer name is a Sym so can't have an export marker
## so exporting definitely happens on the inner one
## what about pragmas? yep. all work gets done on the inner type.

import macros,std/genasts

macro addProc(x:untyped):untyped =
  x.expectKind(nnkTypeDef)
  x[0].expectKind(nnkPragmaExpr)
  var typname = (if x[0][0].kind == nnkPostfix: x[0][0][1] else: x[0][0])
  var typraw = x[0]
  let typ = x[2]
  let body = genast(typ,typraw,typname):
    type typraw = typ # postfix*, pragmas attached here.
    proc foo*(x:typname) = echo x,',',typeof(x)
    proc bar*[T](x:T) = echo x,',',typeof(x),',',T
    typname
  var newtyp = nnkStmtListType.newNimNode
  body.copyChildrenTo(newtyp)
  result = x
  result[0] = gensym(nskType,typname.strval) #make symA refer to identA. pretty neat
  result[2] = newtyp
  echo result.treeRepr

type
  A*{.addProc,deprecated.} = enum hi,lo

foo(A.hi)
bar(A.lo)

var x:A
echo x