import macros, strutils macro typeGen(tName, extra: untyped): untyped = var typeStr = """ type tName = object fname: string age: int""" typeStr = replace(typeStr, "tName", $tName) add(typeStr, "\l ") for f in extra: add(typeStr, repr(f[0]) & ':' & repr(f[1][0])) add(typeStr, "\l ") return parseStmt(typeStr) typeGen Test: a: bool b: byte echo Test()