gistfile1.nim

type
  PBCEnv = ref object
  PBCPattern = int

proc pbc_pattern_new(e:PBCEnv, msg, format: cstring, offsets: varargs[int]): int =
  echo msg, ", ", format
  for n in offsets:
    result += n

macro wrapped_pbc_pattern_new(e: PBCEnv, msg, format: cstring, offsets: varargs[int]): expr =
  result = newCall(!"pbc_pattern_new", e, msg, format)
  for n in offsets.children:
    result.add(n)
  echo result.treeRepr
 
template newPattern*(e: PBCEnv, msg, format: string, offsets: varargs[int]): PBCPattern =
  let result = wrapped_pbc_pattern_new(e, msg, format, offsets)
  if result == 0: # changed this to 'int' for my test
    raise newException(AssertionError, "pbc_pattern_new returned NULL")
  result

echo newPattern(PBCEnv(), "msg", "fmt", 1, 2, 3)