Merge pull request #566 from frootloops/test-algorithm

[tests] basic min/max test cases

Author: gribozavr

stdlib/public/core/Algorithm.swift

@@ -74,27 +74,15 @@ public func min<T : Comparable>(x: T, _ y: T, _ z: T, _ rest: T...) -> T {
 /// Returns the greater of `x` and `y`.
 @warn_unused_result
 public func max<T : Comparable>(x: T, _ y: T) -> T {
-  var r = y
-  if y < x {
-    r = x
-  }
-  return r
+  return y >= x ? y : x
 }
 
 /// Returns the greatest argument passed.
 @warn_unused_result
 public func max<T : Comparable>(x: T, _ y: T, _ z: T, _ rest: T...) -> T {
-  var r = y
-  if y < x {
-    r = x
-  }
-  if r < z {
-    r = z
-  }
-  for t in rest {
-    if t >= r {
-      r = t
-    }
+  var r = max(max(x, y), z)
+  for t in rest where t >= r {
+    r = t
   }
   return r
 }

validation-test/stdlib/Algorithm.swift

@@ -25,14 +25,58 @@ public func == (
 
 // FIXME(prext): move this struct to the point of use.
 Algorithm.test("min,max") {
-  expectEqual(2, min(3, 2))
-  expectEqual(3, min(3, 7, 5))
-  expectEqual(3, max(3, 2))
-  expectEqual(7, max(3, 7, 5))
-
-  // FIXME: add tests that check that min/max return the
-  // first element of the sequence (by reference equality) that satisfy the
-  // condition.
+  // Identities are unique in this set.
+  let a1 = MinimalComparableValue(0, identity: 1)
+  let a2 = MinimalComparableValue(0, identity: 2)
+  let a3 = MinimalComparableValue(0, identity: 3)
+  let b1 = MinimalComparableValue(1, identity: 4)
+  let b2 = MinimalComparableValue(1, identity: 5)
+  let b3 = MinimalComparableValue(1, identity: 6)
+  let c1 = MinimalComparableValue(2, identity: 7)
+  let c2 = MinimalComparableValue(2, identity: 8)
+  let c3 = MinimalComparableValue(2, identity: 9)
+
+  // 2-arg min()
+  expectEqual(a1.identity, min(a1, b1).identity)
+  expectEqual(a1.identity, min(b1, a1).identity)
+  expectEqual(a1.identity, min(a1, a2).identity)
+
+  // 2-arg max()
+  expectEqual(c1.identity, max(c1, b1).identity)
+  expectEqual(c1.identity, max(b1, c1).identity)
+  expectEqual(c1.identity, max(c2, c1).identity)
+
+  // 3-arg min()
+  expectEqual(a1.identity, min(a1, b1, c1).identity)
+  expectEqual(a1.identity, min(b1, a1, c1).identity)
+  expectEqual(a1.identity, min(c1, b1, a1).identity)
+  expectEqual(a1.identity, min(c1, a1, b1).identity)
+  expectEqual(a1.identity, min(a1, a2, a3).identity)
+  expectEqual(a1.identity, min(a1, a2, b1).identity)
+  expectEqual(a1.identity, min(a1, b1, a2).identity)
+  expectEqual(a1.identity, min(b1, a1, a2).identity)
+ 
+  // 3-arg max()
+  expectEqual(c1.identity, max(c1, b1, a1).identity)
+  expectEqual(c1.identity, max(a1, c1, b1).identity)
+  expectEqual(c1.identity, max(b1, a1, c1).identity)
+  expectEqual(c1.identity, max(b1, c1, a1).identity)
+  expectEqual(c1.identity, max(c3, c2, c1).identity)
+  expectEqual(c1.identity, max(c2, c1, b1).identity)
+  expectEqual(c1.identity, max(c2, b1, c1).identity)
+  expectEqual(c1.identity, max(b1, c2, c1).identity)
+  
+  // 4-arg min()
+  expectEqual(a1.identity, min(a1, b1, a2, b2).identity)
+  expectEqual(a1.identity, min(b1, a1, a2, b2).identity)
+  expectEqual(a1.identity, min(c1, b1, b2, a1).identity)
+  expectEqual(a1.identity, min(c1, b1, a1, a2).identity)
+  
+  // 4-arg max()
+  expectEqual(c1.identity, max(c2, b1, c1, b2).identity)
+  expectEqual(c1.identity, max(b1, c2, c1, b2).identity)
+  expectEqual(c1.identity, max(a1, b1, b2, c1).identity)
+  expectEqual(c1.identity, max(a1, b1, c2, c1).identity)
 }
 
 Algorithm.test("sorted/strings")