feat(math): narrow return type for min(), max(), median() and `…

…mean()` (#464)
azjezz · Apr 6, 2024 · a33de34 · a33de34
1 parent 765f499
commit a33de34
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Showing 5 changed files with 11 additions and 7 deletions.
diff --git a/docs/component/math.md b/docs/component/math.md
@@ -54,8 +54,8 @@
 - [max](./../../src/Psl/Math/max.php#L19)
 - [max_by](./../../src/Psl/Math/max_by.php#L24)
 - [maxva](./../../src/Psl/Math/maxva.php#L20)
-- [mean](./../../src/Psl/Math/mean.php#L18)
-- [median](./../../src/Psl/Math/median.php#L19)
+- [mean](./../../src/Psl/Math/mean.php#L20)
+- [median](./../../src/Psl/Math/median.php#L21)
 - [min](./../../src/Psl/Math/min.php#L19)
 - [min_by](./../../src/Psl/Math/min_by.php#L24)
 - [minva](./../../src/Psl/Math/minva.php#L20)

diff --git a/src/Psl/Math/max.php b/src/Psl/Math/max.php
@@ -12,7 +12,7 @@
  *
  * @param list<T> $numbers
  *
- * @return T|null
+ * @return ($numbers is non-empty-list<T> ? T : null)
  *
  * @pure
  */

diff --git a/src/Psl/Math/mean.php b/src/Psl/Math/mean.php
@@ -13,9 +13,11 @@
  *
  * @param list<int|float> $numbers
  *
+ * @return ($numbers is non-empty-list ? float : null)
+ *
  * @pure
  */
-function mean(array $numbers): ?float
+function mean(array $numbers): float|null
 {
     $count = (float) count($numbers);
     if (0.0 === $count) {

diff --git a/src/Psl/Math/median.php b/src/Psl/Math/median.php
@@ -14,9 +14,11 @@
  *
  * @param list<int|float> $numbers
  *
+ * @return ($numbers is non-empty-list ? float : null)
+ *
  * @pure
  */
-function median(array $numbers): ?float
+function median(array $numbers): float|null
 {
     sort($numbers);
     $count   = count($numbers);
@@ -29,7 +31,7 @@ function median(array $numbers): ?float
     if (0 === $count % 2) {
         return mean(
             [$numbers[$middle_index], $numbers[$middle_index - 1]]
-        ) ?? 0.0;
+        );
     }
 
     return (float) $numbers[$middle_index];

diff --git a/src/Psl/Math/min.php b/src/Psl/Math/min.php
@@ -12,7 +12,7 @@
  *
  * @param list<T> $numbers
  *
- * @return T|null
+ * @return ($numbers is non-empty-list<T> ? T : null)
  *
  * @pure
  */
-Original file line number
+Diff line change
@@ Expand Up / @@ -12,7 +12,7 @@ @@
      *
      * @param list<T> $numbers
      *
-     * @return T|null
+     * @return ($numbers is non-empty-list<T> ? T : null)
      *
      * @pure
      */
@@ Expand Down @@