Data commit

Task/Monads-Writer-monad/Nim/monads-writer-monad.nim

@@ -0,0 +1,19 @@
+from math import sqrt
+from sugar import `=>`, `->`
+
+type
+  WriterUnit = (float, string)
+  WriterBind = proc(a: WriterUnit): WriterUnit
+
+proc bindWith(f: (x: float) -> float; log: string): WriterBind =
+  result = (a: WriterUnit) => (f(a[0]), a[1] & log)
+
+func doneWith(x: int): WriterUnit =
+  (x.float, "")
+
+var
+  logRoot = sqrt.bindWith "obtained square root, "
+  logAddOne = ((x: float) => x+1'f).bindWith "added 1, "
+  logHalf = ((x: float) => x/2'f).bindWith "divided by 2, "
+
+echo 5.doneWith.logRoot.logAddOne.logHalf