From 43ef31e7723e41601f4c9c5c6996515a2f83143b Mon Sep 17 00:00:00 2001
From: Roman Galochkin <roman.redrat@gmail.com>
Date: Tue, 25 Feb 2020 09:16:14 +0300
Subject: [PATCH] Adds a "range" function

---
 src/utility/lib/Functions.re | 16 +++++++++++++++-
 src/utility/lib/functions.js |  1 +
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/utility/lib/Functions.re b/src/utility/lib/Functions.re
index d6db7a03..a887be60 100644
--- a/src/utility/lib/Functions.re
+++ b/src/utility/lib/Functions.re
@@ -1,3 +1,5 @@
+exception RangeWrong(string);
+
 let interpolate =
     (xMin: float, xMax: float, yMin: float, yMax: float, xIntended: float)
     : float => {
@@ -7,10 +9,22 @@ let interpolate =
 };
 
 // @todo: To test!
-/* https://bucklescript.github.io/bucklescript/api/Belt.html */
 let sum = Belt.Array.reduce(_, 0., (i, j) => i +. j);
 let mean = a => sum(a) /. (Array.length(a) |> float_of_int);
 let min = Belt.Array.reduce(_, 0., (i, j) => i < j ? i : j);
 let max = Belt.Array.reduce(_, 0., (i, j) => i > j ? i : j);
 let up = (a, b) => Array.make(b - a, a) |> Array.mapi((i, c) => c + i);
 let down = (a, b) => Array.make(a - b, a) |> Array.mapi((i, c) => c - i);
+let range = (min: float, max: float, n: int): array(float) => {
+  switch (n) {
+  | 0 => [||]
+  | 1 => [|min|]
+  | 2 => [|min, max|]
+  | _ when min == max => Belt.Array.make(n, min)
+  | _ when n < 0 => raise(RangeWrong("n is less then zero"))
+  | _ when min > max => raise(RangeWrong("Min values is less then max"))
+  | _ =>
+    let diff = max -. min;
+    Belt.Array.makeBy(n, i => float_of_int(i) *. diff);
+  };
+};
diff --git a/src/utility/lib/functions.js b/src/utility/lib/functions.js
index a234c799..a4353e52 100644
--- a/src/utility/lib/functions.js
+++ b/src/utility/lib/functions.js
@@ -14,6 +14,7 @@ function interpolate(xMin, xMax, yMin, yMax, xIntended) {
 }
 
 /**
+ * @Done
  * This should return an array of n evenly-spaced items
  * between min and max, including min and max.
  * range(1,5,3) = [1, 3, 5];