added lookuptables.nim helper module

karax/lookuptables.nim

@@ -0,0 +1,24 @@
+
+import macros, kbase
+from strutils import `%`
+
+macro fieldNamesAsArray*(t: typed; pattern = "$1"): untyped =
+  var impl = getTypeImpl(getTypeImpl(t)[1])
+  if impl.kind == nnkRefTy: impl = getTypeImpl(impl[0])
+  expectKind impl, nnkObjectTy
+  impl = impl[2]
+  expectKind impl, nnkRecList
+  result = newTree(nnkBracket)
+  for x in impl:
+    expectKind x, nnkIdentDefs
+    result.add(newCall(bindSym"kstring", newLit(pattern.strVal % $x[0])))
+
+when isMainModule:
+  type
+    MyObject = ref object
+      x*: string
+      next*: int
+      more, here*: float
+
+  const myObjectFields = fieldNamesAsArray(MyObject, "MyObject_$1")
+  for f in myObjectFields: echo f