add sort.min and sort.max functions to stdlib

andrewrk · andrewrk · commit 1435604b84db · 2017-12-19T17:35:38.000-05:00
diff --git a/std/mem.zig b/std/mem.zig
@@ -511,9 +511,8 @@ fn testWriteIntImpl() {
 
 pub fn min(comptime T: type, slice: []const T) -> T {
     var best = slice[0];
-    var i: usize = 1;
-    while (i < slice.len) : (i += 1) {
-        best = math.min(best, slice[i]);
+    for (slice[1..]) |item| {
+        best = math.min(best, item);
     }
     return best;
 }
@@ -524,9 +523,8 @@ test "mem.min" {
 
 pub fn max(comptime T: type, slice: []const T) -> T {
     var best = slice[0];
-    var i: usize = 1;
-    while (i < slice.len) : (i += 1) {
-        best = math.max(best, slice[i]);
+    for (slice[1..]) |item| {
+        best = math.max(best, item);
     }
     return best;
 }
diff --git a/std/sort.zig b/std/sort.zig
@@ -1132,3 +1132,25 @@ fn fuzzTest(rng: &std.rand.Rand) {
         }
     }
 }
+
+pub fn min(comptime T: type, items: []T, lessThan: fn(lhs: &const T, rhs: &const T)->bool) -> T {
+    var i: usize = 0;
+    var smallest = items[0];
+    for (items[1..]) |item| {
+        if (lessThan(item, smallest)) {
+            smallest = item;
+        }
+    }
+    return smallest;
+}
+
+pub fn max(comptime T: type, items: []T, lessThan: fn(lhs: &const T, rhs: &const T)->bool) -> T {
+    var i: usize = 0;
+    var biggest = items[0];
+    for (items[1..]) |item| {
+        if (lessThan(biggest, item)) {
+            biggest = item;
+        }
+    }
+    return biggest;
+}

Original file line number	Diff line number	Diff line change
`@@ -511,9 +511,8 @@ fn testWriteIntImpl() {`
`511`	`511`
`512`	`512`	`pub fn min(comptime T: type, slice: []const T) -> T {`
`513`	`513`	`var best = slice[0];`
`514`		`- var i: usize = 1;`
`515`		`- while (i < slice.len) : (i += 1) {`
`516`		`- best = math.min(best, slice[i]);`
	`514`	`+ for (slice[1..]) \|item\| {`
	`515`	`+ best = math.min(best, item);`
`517`	`516`	`}`
`518`	`517`	`return best;`
`519`	`518`	`}`
`@@ -524,9 +523,8 @@ test "mem.min" {`
`524`	`523`
`525`	`524`	`pub fn max(comptime T: type, slice: []const T) -> T {`
`526`	`525`	`var best = slice[0];`
`527`		`- var i: usize = 1;`
`528`		`- while (i < slice.len) : (i += 1) {`
`529`		`- best = math.max(best, slice[i]);`
	`526`	`+ for (slice[1..]) \|item\| {`
	`527`	`+ best = math.max(best, item);`
`530`	`528`	`}`
`531`	`529`	`return best;`
`532`	`530`	`}`