Add minElement / maxElement

Author: jmh530

source/mir/algorithm/iteration.d

@@ -20,8 +20,10 @@ $(T2 find, Finds backward index.)
 $(T2 findIndex, Finds index.)
 $(T2 fold, Accumulates all elements (different parameter order than `reduce`).)
 $(T2 isSymmetric, Checks if the matrix is symmetric.)
+$(T2 maxElement, Returns the maximum.)
 $(T2 maxIndex, Finds index of the maximum.)
 $(T2 maxPos, Finds backward index of the maximum.)
+$(T2 maxIndex, Returns the minimum.)
 $(T2 minIndex, Finds index of the minimum.)
 $(T2 minmaxIndex, Finds indices of the minimum and the maximum.)
 $(T2 minmaxPos, Finds backward indices of the minimum and the maximum.)
@@ -4432,3 +4434,86 @@ unittest
  auto z4 = y.minIndex;
  auto z5 = y.maxIndex;
 }
+
+/++
+Returns the minimal(maximal) element of a multidimensional slice.
+
+Params:
+ pred = A predicate.
+
+See_also:
+ $(LREF minIndex),
+ $(LREF maxElement),
+ $(LREF maxIndex),
+ $(LREF maxPos).
++/
+template minElement(alias pred = "a < b")
+{
+ import mir.functional: naryFun;
+ static if (__traits(isSame, naryFun!pred, pred))
+ /++
+ Params:
+ slice = ndslice.
+ Returns:
+ Minimal(maximal) element of a multidimensional slice
+ +/
+ @fmamath DeepElementType!(Slice!(Iterator, N, kind)) minElement(Iterator, size_t N, SliceKind kind)(Slice!(Iterator, N, kind) slice)
+ {
+ return slice[slice.minIndex!pred];
+ }
+ else
+ alias minElement = .minElement!(naryFun!pred);
+}
+
+/// ditto
+template maxElement(alias pred = "a < b")
+{
+ import mir.functional: naryFun, reverseArgs;
+ alias maxElement = minElement!(reverseArgs!(naryFun!pred));
+}
+
+///
+@safe pure nothrow
+version(mir_test)
+unittest
+{
+ import mir.ndslice.slice: sliced;
+ auto s = [
+ 2, 6, 4, -3,
+ 0, -4, -3, 3,
+ -3, -2, 7, 8,
+ ].sliced(3, 4);
+
+ assert(s.minElement == -4);
+ assert(s.maxElement == 8);
+}
+
+///
+@safe pure nothrow
+version(mir_test)
+unittest
+{
+ import mir.ndslice.slice: sliced;
+ auto s = [
+ -8, 6, 4, -3,
+ 0, -4, -3, 3,
+ -3, -2, 7, 8,
+ ].sliced(3, 4);
+
+ assert(s.minElement == -8);
+}
+
+@safe pure nothrow
+version(mir_test)
+unittest
+{
+ import mir.ndslice.slice: sliced;
+ auto s = [
+ 0, 1, 2, 3,
+ 4, 5, 6, 7,
+ 8, 9, 10, 11
+ ].sliced(3, 4);
+
+ assert(s.minElement == 0);
+ assert(s.maxElement == 11);
+}