Data commit

Task/Monads-Maybe-monad/Nim/monads-maybe-monad.nim

@@ -0,0 +1,25 @@
+import options,math,sugar,strformat
+template checkAndWrap(x:float,body:typed): untyped =
+  if x.classify in {fcNormal,fcZero,fcNegZero}:
+    some(body)
+  else:
+    none(typeof(body))
+func reciprocal(x:float):Option[float] =
+  let res = 1 / x
+  res.checkAndWrap(res)
+func log(x:float):Option[float] =
+  let res = ln(x)
+  res.checkAndWrap(res)
+func format(x:float):Option[string] =
+  x.checkAndWrap(&"{x:.2f}")
+
+#our bind function:
+func `-->`[T,U](input:Option[T], f: T->Option[U]):Option[U] =
+  if input.isSome:
+    f(input.get)
+  else:
+    none(U)
+
+when isMainModule:
+  for i in [0.9,0.0,-0.9,3.0]:
+    echo some(i) --> reciprocal --> log --> format