Data commit

Task/Nested-templated-data/Nim/nested-templated-data.nim

@@ -0,0 +1,28 @@
+import macros,sugar,strformat
+#macro to take a nested tuple and return a type
+#e.g. (int,(int,int))=>(string,(string,string))
+proc intstr(n: NimNode): NimNode =
+  if n.kind == nnkSym:
+    return ident("string")
+  result = nnkPar.newNimNode()
+  for i in 1..<n.len:
+    result.add(intstr(n[i]))
+
+macro tuptype(t: typed): untyped = intstr(t.getType)
+
+
+proc replace(t: tuple | int, p: openArray[string]): auto =
+  when t is int: (if t in 0..<p.len: p[t] else: "nil")
+  else:
+    var res: tuptype(t)
+    for k, v in t.fieldpairs:
+      #k will be 'Field0', so we convert to an integer index
+      res[k[^1].int - '0'.int] = replace(v, p)
+    return res
+when isMainModule:
+  let p = collect(for i in 0..5: &"payload{i}")
+
+  let tplt1 = ((1,2),(3,4,1),5)
+  let tplt2 = ((1,2),(3,4,1),6)
+  echo replace(tplt1, p)
+  echo replace(tplt2, p)