fix hash function

ranges/typedranges.nim

@@ -50,13 +50,6 @@ proc toRange*[T](a: seq[T]): Range[T] {.inline.} = toImmutableRange(a)
 
 converter toImmutableRange*[T](a: MutRange[T]): Range[T] {.inline.} = Range[T](a)
 
-proc hash*(x: Range): Hash =
-  var h: Hash = 0
-  when rangesGCHoldEnabled:
-    h = h !& hash(x.gcHold)
-  h = h !& hash(x.mLen)
-  result = !$h
-
 proc len*(r: Range): int {.inline.} = int(r.mLen)
 
 proc high*(r: Range): int {.inline.} = r.len - 1
@@ -181,3 +174,6 @@ proc `&`*[T](a, b: Range[T]): seq[T] =
   result = newSeq[T](a.len + b.len)
   copyRange(T, result, 0, a)
   copyRange(T, result, a.len, b)
+
+proc hash*(x: Range): Hash =
+  result = hash(toOpenArray(x))

tests/ttypedranges.nim

@@ -76,6 +76,8 @@ suite "Typed ranges":
     var a = toRange(@[1,2,3])
     var b = toRange(@[4,5,6])
     var c = toRange(@[7,8,9])
+    var d = toRange(@[1,2,3,4,5,6,7,8,9])
+    var e = toRange(@[1,2,3,4,5,6,7,8,9])
     var x = toSet([a, b, c, a, b])
     check x.len == 3
     check a in x
@@ -84,3 +86,13 @@ suite "Typed ranges":
     var y = toSet([z, b, c])
     check z in y
     check z in x
+
+    var u = d[0..2]
+    var v = d[3..5]
+    var uu = e[0..2]
+    var vv = e[3..5]
+    check hash(u) != hash(v)
+    check hash(uu) == hash(u)
+    check hash(v) == hash(vv)
+    check hash(uu) != hash(vv)
+