From 1397ad7c5459d48c10cc19d487dc856bcb78e81a Mon Sep 17 00:00:00 2001
From: WhiteDuke <Wh1teDuke@users.noreply.github.com>
Date: Mon, 25 Feb 2019 16:45:44 +0100
Subject: [PATCH] [random] add support for sets (#10532)

* Support for sets

* Rename 'rand' to 'sample'

* Update random.nim
---
 lib/pure/random.nim | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/lib/pure/random.nim b/lib/pure/random.nim
index 86db7da497..4115d147b3 100644
--- a/lib/pure/random.nim
+++ b/lib/pure/random.nim
@@ -390,6 +390,18 @@ proc rand*[T](a: openArray[T]): T {.deprecated.} =
   ## Use `sample[T](openArray[T])<#sample,openArray[T]>`_ instead.
   result = a[rand(a.low..a.high)]
 
+proc sample*[T](r: var Rand; s: set[T]): T =
+  ## returns a random element from a set
+  assert card(s) != 0
+  var i = rand(r, card(s) - 1)
+  for e in s:
+    if i == 0: return e
+    dec(i)
+    
+proc sample*[T](s: set[T]): T =
+  ## returns a random element from a set
+  sample(state, s)
+
 proc sample*[T](r: var Rand; a: openArray[T]): T =
   ## Returns a random element from ``a`` using the given state.
   ##