Add create_assoc function

composer.json

@@ -20,7 +20,8 @@
     "require-dev": {
         "phpunit/phpunit": "~6",
         "squizlabs/php_codesniffer": "~3.0",
-        "friendsofphp/php-cs-fixer": "^2.14"
+        "friendsofphp/php-cs-fixer": "^2.14",
+        "apantle/hashmapper": "^1.3"
     },
     "autoload": {
         "psr-4": {"Functional\\": "src/Functional"},
@@ -35,6 +36,7 @@
             "src/Functional/Concat.php",
             "src/Functional/Contains.php",
             "src/Functional/Converge.php",
+            "src/Functional/CreateAssoc.php",
             "src/Functional/Curry.php",
             "src/Functional/CurryN.php",
             "src/Functional/Difference.php",

src/Functional/CreateAssoc.php

@@ -0,0 +1,62 @@
+<?php
+/**
+ * Copyright (C) 2019 by Jesus Franco Martinez <[email protected]>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+namespace Functional;
+
+/**
+ * Return a function that applies a set of functions to build an
+ * associative array from a single input (scalar, object or sequence)
+ *
+ * @param array $specs associative array of keys and functions that map to the target
+ * @param object|null $tameme
+ * @return callable
+ */
+function create_assoc(array $specs, $tameme = null): callable
+{
+    return function ($input, $optional = null) use ($specs, $tameme) {
+        $mecapal = [];
+
+        foreach ($specs as $target => $mapper) {
+            $mecapal[$target] = is_unary($mapper)
+              ? \call_user_func($mapper, $input)
+              : \call_user_func($mapper, $input, $optional, $tameme)
+            ;
+        }
+
+        return $mecapal;
+    };
+}
+
+/**
+ * determine if the callable passed expect only one argument
+ * @param callable $callable
+ * @return bool
+ * @throws \ReflectionException
+ */
+function is_unary($callable)
+{
+    if (!\is_callable($callable)) {
+        return false;
+    }
+    $reflector = new \ReflectionFunction($callable);
+    return \boolval($reflector->getNumberOfParameters() === 1);
+}

src/Functional/Functional.php

@@ -54,6 +54,11 @@ final class Functional
      */
     const converge = '\Functional\converge';
 
+    /**
+     * @see \Functional\create_assoc
+     */
+    const create_assoc = '\Functional\create_assoc';
+
     /**
      * @see \Functional\curry
      */
@@ -169,6 +174,11 @@ final class Functional
      */
     const identical = '\Functional\identical';
 
+    /**
+     * @see \Functional\is_unary
+     */
+    const is_unary = '\Functional\is_unary';
+
     /**
      * @see \Functional\if_else
      */

tests/Functional/CreateAssocTest.php

@@ -0,0 +1,129 @@
+<?php
+/**
+ * Copyright (C) 2019 by Jesus Franco Martinez <[email protected]>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+namespace Functional\Tests;
+
+use Functional\Functional;
+
+use function Functional\create_assoc;
+use function Apantle\HashMapper\hashMapper;
+
+class CreateAssocTest extends AbstractTestCase
+{
+    public function testBasicCreateAssoc()
+    {
+        $input = new \DateTimeImmutable();
+
+        $expected = [
+          'targetA' => $input,
+          'targetB' => $input
+        ];
+
+        $actual = create_assoc([
+          'targetA' => Functional::id,
+          'targetB' => Functional::id,
+        ])($input);
+
+        $this->assertEquals($expected, $actual);
+        $this->assertEquals($input->format('U'), $actual['targetA']->format('U'));
+        $this->assertEquals($input->format('U'), $actual['targetB']->format('U'));
+    }
+
+    public function testExpectsTameme()
+    {
+        $input = [ 1, 2, 3 ];
+
+        $expected = [
+          'targetA' => [ 4 => 1, 5 => 2, 6 => 3 ],
+          'targetB' => [ 5 => 2 ]
+        ];
+        // phpcs:disable
+        $tameme = new class extends \ArrayObject {};
+        // phpcs:enable
+        $_irrelevant = null;
+        $actual = create_assoc([
+          'targetA' => function ($member, $_irrelevant, $tameme) {
+              $build = \array_reduce($member, function ($accum, $num) {
+                  $accum[$num + 3] = $num;
+                  return $accum;
+              }, []);
+
+              $tameme['prev'] = $build;
+              return $build;
+          },
+          'targetB' => function ($member, $input, $tameme) {
+            $prev = $tameme['prev'];
+            $build = [];
+            foreach ($prev as $key => $val) {
+                if ($key % 2 !== 0) {
+                    $build[$key] = $val;
+                }
+            }
+            return $build;
+          }
+        ], $tameme)($input);
+
+        $this->assertEquals($expected, $actual);
+    }
+
+    public function testReceivesOptionalArgument()
+    {
+        $input = [
+          'vendor' => 'tzkmx',
+          'utility' => 'unfold'
+        ];
+
+        $expected = [
+          'vendorName' => 'tzkmx',
+          'vendorLen' => 5,
+          'serialized' => 'a:2:{s:6:"vendor";s:5:"tzkmx";s:7:"utility";s:6:"unfold";}',
+          'utility' => 'unfold',
+          'utilLen' => 6,
+          'package' => [ 'tzkmx/unfold' => $input ]
+        ];
+        // phpcs:disable
+        $tameme = new class extends \ArrayObject {};
+        // phpcs:enable
+        $actual = hashMapper([
+          'vendor' => [ '...', create_assoc([
+            'vendorName' => 'strval',
+            'vendorLen' => 'strlen',
+            'serialized' => function ($member, $hash, $tameme) {
+                $tameme['name'] = $member;
+                return \serialize($hash);
+            }
+          ], $tameme)
+          ],
+          'utility' => [ '...', create_assoc([
+            'utility' => 'strval',
+            'utilLen' => 'strlen',
+            'package' => function ($member, $hash, $tameme) {
+                $name = $tameme['name'];
+                return [ "$name/$member" => $hash ];
+            }
+          ], $tameme)
+          ]
+        ])($input);
+
+        $this->assertEquals($expected, $actual);
+    }
+}