Add `sum()` and `sumBy()`.

src/collections_me.c

@@ -206,6 +206,8 @@ const zend_function_entry collection_methods[] = {
     PHP_ME(Collection, sortedByDescending, selector_flags_arginfo, ZEND_ACC_PUBLIC)
     PHP_ME(Collection, sortedDescending, flags_arginfo, ZEND_ACC_PUBLIC)
     PHP_ME(Collection, sortedWith, comparator_arginfo, ZEND_ACC_PUBLIC)
+    PHP_ME(Collection, sum, NULL, ZEND_ACC_PUBLIC)
+    PHP_ME(Collection, sumBy, selector_arginfo, ZEND_ACC_PUBLIC)
     PHP_ME(Collection, take, n_arginfo, ZEND_ACC_PUBLIC)
     PHP_ME(Collection, takeLast, n_arginfo, ZEND_ACC_PUBLIC)
     PHP_ME(Collection, takeLastWhile, predicate_arginfo, ZEND_ACC_PUBLIC)

src/collections_methods.c

@@ -2702,6 +2702,71 @@ PHP_METHOD(Collection, sortedWith)
     RETVAL_NEW_COLLECTION(sorted_with);
 }
 
+PHP_METHOD(Collection, sum)
+{
+    zend_array* current = COLLECTION_FETCH_CURRENT();
+    zval sum;
+    ZVAL_NULL(&sum);
+    ZEND_HASH_FOREACH_VAL(current, zval* val)
+        if (UNEXPECTED(ZVAL_IS_NULL(&sum))) {
+            if (Z_TYPE_P(val) == IS_LONG) {
+                ZVAL_LONG(&sum, 0);
+            } else if (EXPECTED(Z_TYPE_P(val) == IS_DOUBLE)) {
+                ZVAL_DOUBLE(&sum, 0.0);
+            } else {
+                ERR_NOT_NUMERIC();
+                RETURN_NULL();
+            }
+        }
+        if (Z_TYPE_P(val) == IS_LONG) {
+            Z_LVAL(sum) += Z_LVAL_P(val);
+        } else if (EXPECTED(Z_TYPE_P(val) == IS_DOUBLE)) {
+            Z_DVAL(sum) += Z_DVAL_P(val);
+        } else {
+            ERR_NOT_NUMERIC();
+            RETURN_NULL();
+        }
+    ZEND_HASH_FOREACH_END();
+    RETVAL_ZVAL(&sum, 0, 0);
+}
+
+PHP_METHOD(Collection, sumBy)
+{
+    zend_fcall_info fci;
+    zend_fcall_info_cache fcc;
+    ZEND_PARSE_PARAMETERS_START(1, 1)
+        Z_PARAM_FUNC(fci, fcc)
+    ZEND_PARSE_PARAMETERS_END();
+    zend_array* current = COLLECTION_FETCH_CURRENT();
+    zval sum;
+    ZVAL_NULL(&sum);
+    INIT_FCI(&fci, 2);
+    ZEND_HASH_FOREACH_BUCKET(current, Bucket* bucket)
+        CALLBACK_KEYVAL_INVOKE(params, bucket);
+        if (UNEXPECTED(ZVAL_IS_NULL(&sum))) {
+            if (Z_TYPE(retval) == IS_LONG) {
+                ZVAL_LONG(&sum, 0);
+            } else if (EXPECTED(Z_TYPE(retval) == IS_DOUBLE)) {
+                ZVAL_DOUBLE(&sum, 0.0);
+            } else {
+                ERR_NOT_NUMERIC();
+                zval_ptr_dtor(&retval);
+                RETURN_NULL();
+            }
+        }
+        if (Z_TYPE(retval) == IS_LONG) {
+            Z_LVAL(sum) += Z_LVAL(retval);
+        } else if (EXPECTED(Z_TYPE(retval) == IS_DOUBLE)) {
+            Z_DVAL(sum) += Z_DVAL(retval);
+        } else {
+            ERR_NOT_NUMERIC();
+            zval_ptr_dtor(&retval);
+            RETURN_NULL();
+        }
+    ZEND_HASH_FOREACH_END();
+    RETVAL_ZVAL(&sum, 0, 0);
+}
+
 PHP_METHOD(Collection, take)
 {
     zend_long n;

src/php_collections_me.h

@@ -94,6 +94,8 @@ PHP_METHOD(Collection, sortedBy);
 PHP_METHOD(Collection, sortedByDescending);
 PHP_METHOD(Collection, sortedDescending);
 PHP_METHOD(Collection, sortedWith);
+PHP_METHOD(Collection, sum);
+PHP_METHOD(Collection, sumBy);
 PHP_METHOD(Collection, take);
 PHP_METHOD(Collection, takeLast);
 PHP_METHOD(Collection, takeLastWhile);

stubs/Collection.php

@@ -807,6 +807,27 @@ class Collection implements ArrayAccess, Countable
      */
     function sortedWith($comparator) {}
 
+    /**
+     * Returns the sum of all elements in the collection.
+     * 
+     * All elements should be of the same type, int or double. Otherwise result is undefined.
+     * 
+     * @return int|double|null
+     */
+    function sum() {}
+
+    /**
+     * Returns the sum of all values produced by selector function applied to each element
+     * in the collection.
+     * 
+     * All return values of the selector function should be of the same type, int or double.
+     * Otherwise result is undefined.
+     * 
+     * @param callable $selector ($value, $key) -> int|double
+     * @return int|double|null
+     */
+    function sumBy($selector) {}
+
     /**
      * Returns a collection containing first n elements.
      *

tests/054-sum-by.phpt

@@ -0,0 +1,26 @@
+--TEST--
+Test Collection::sum() and Collection::sumBy().
+--FILE--
+<?php
+$array = [];
+for ($i = 0; $i < 50; ++$i) {
+    $array[] = random_int(1, 50);
+}
+$collection = Collection::init($array);
+$sum = array_sum($array);
+if ($collection->sum() != $sum) {
+    echo 'Collection::sum() failed.', PHP_EOL;
+}
+$array = array_map(function ($value) {
+    return [$value, floatval($value / random_int(3, 7))];
+}, $array);
+$collection = Collection::init($array);
+$sum = array_sum(array_column($array, 1));
+$sum_by = function ($value) {
+    return $value[1];
+};
+if ($collection->sumBy($sum_by) != $sum) {
+    echo 'Collection::sumBy() failed.', PHP_EOL;
+}
+?>
+--EXPECT--