Support variadic pass-through arguments (#3)

Makes it easier to handle arguments acquired in consecutive steps that depend on earlier results
prewk · Feb 3, 2018 · 2f19406 · 2f19406
1 parent eb99451
commit 2f19406
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Showing 6 changed files with 129 additions and 13 deletions.
diff --git a/helpers.php b/helpers.php
@@ -5,16 +5,17 @@
  * @author Oskar Thornblad
  */
 
-if (!function_exists("ok")) {    
+if (!function_exists("ok")) {
     /**
      * Represent a successful result
      *
      * @codeCoverageIgnore
      * @param mixed $value
+     * @param array ...$pass
      * @return Prewk\Result\Ok
      */
-    function ok($value = null): Prewk\Result\Ok {
-        return new Prewk\Result\Ok($value);
+    function ok($value = null, ...$pass): Prewk\Result\Ok {
+        return new Prewk\Result\Ok($value, ...$pass);
     }
 }
 
@@ -23,10 +24,11 @@ function ok($value = null): Prewk\Result\Ok {
      * Represent a failed result
      *
      * @codeCoverageIgnore
-     * @param mixed $value
+     * @param $err
+     * @param array ...$pass
      * @return Prewk\Result\Err
      */
-    function err($err): Prewk\Result\Err {
-        return new Prewk\Result\Err($err);
+    function err($err, ...$pass): Prewk\Result\Err {
+        return new Prewk\Result\Err($err, $pass);
     }
 }
diff --git a/spec/Result/ErrSpec.php b/spec/Result/ErrSpec.php
@@ -153,4 +153,37 @@ function it_does_not_apply_args_in_an_err()
         $this->beConstructedWith("error");
         $this->apply(new Ok(123))->isErr()->shouldBe(true);
     }
+
+    function it_mapErrs_with_pass_args()
+    {
+        $this->beConstructedWith("foo", "bar", "baz");
+        $result = $this->mapErr(function($foo, $bar, $baz) {
+            return $foo . $bar . $baz;
+        });
+
+        $result->shouldHaveType(Err::class);
+        $result->unwrapErr()->shouldBe("foobarbaz");
+    }
+
+    function it_orElses_with_pass_args()
+    {
+        $this->beConstructedWith("foo", "bar", "baz");
+        $result = $this->orElse(function($foo, $bar, $baz) {
+            return new Err($foo . $bar . $baz);
+        });
+
+        $result->unwrapErr()->shouldBe("foobarbaz");
+    }
+
+    function its_with_method_adds_args()
+    {
+        $this->beConstructedWith("foo");
+        $this->with("bar", "baz");
+
+        $result = $this->orElse(function($foo, $bar, $baz) {
+            return new Err($foo . $bar . $baz);
+        });
+
+        $result->unwrapErr()->shouldBe("foobarbaz");
+    }
 }
diff --git a/spec/Result/OkSpec.php b/spec/Result/OkSpec.php
@@ -168,4 +168,37 @@ function it_throws_if_non_callable_value_is_applied_to_arguments()
         $this->beConstructedWith(1);
         $this->shouldThrow(ResultException::class)->during("apply");
     }
+
+    function it_maps_with_pass_args()
+    {
+        $this->beConstructedWith("foo", "bar", "baz");
+        $result = $this->map(function($foo, $bar, $baz) {
+            return $foo . $bar . $baz;
+        });
+
+        $result->shouldHaveType(Ok::class);
+        $result->unwrap()->shouldBe("foobarbaz");
+    }
+
+    function it_andThens_with_pass_args()
+    {
+        $this->beConstructedWith("foo", "bar", "baz");
+        $result = $this->andThen(function($foo, $bar, $baz) {
+            return new Ok($foo . $bar . $baz);
+        });
+
+        $result->unwrap()->shouldBe("foobarbaz");
+    }
+
+    function its_with_method_adds_args()
+    {
+        $this->beConstructedWith("foo");
+        $this->with("bar", "baz");
+
+        $result = $this->andThen(function($foo, $bar, $baz) {
+            return new Ok($foo . $bar . $baz);
+        });
+
+        $result->unwrap()->shouldBe("foobarbaz");
+    }
 }
diff --git a/src/Result.php b/src/Result.php
@@ -150,4 +150,12 @@ public function unwrapErr();
      * @return Result
      */
     public function apply(Result ...$args): Result;
+
+    /**
+     * The attached pass-through args will be unpacked into extra args into chained closures
+     *
+     * @param array ...$args
+     * @return Result
+     */
+    public function with(...$args): Result;
 }
diff --git a/src/Result/Err.php b/src/Result/Err.php
@@ -26,14 +26,21 @@ class Err implements Result
      */
     private $err;
 
+    /**
+     * @var array
+     */
+    private $pass;
+
     /**
      * Err constructor.
      *
      * @param mixed $err
+     * @param array ...$pass
      */
-    public function __construct($err)
+    public function __construct($err, ...$pass)
     {
         $this->err = $err;
+        $this->pass = $pass;
     }
 
     /**
@@ -75,7 +82,7 @@ public function map(Closure $mapper): Result
      */
     public function mapErr(Closure $mapper): Result
     {
-        return new self($mapper($this->err));
+        return new self($mapper($this->err, ...$this->pass));
     }
 
     /**
@@ -131,7 +138,7 @@ public function or(Result $res): Result
      */
     public function orElse(Closure $op): Result
     {
-        $result = $op($this->err);
+        $result = $op($this->err, ...$this->pass);
 
         if (!($result instanceof Result)) {
             throw new ResultException("Op must return a Result");
@@ -159,7 +166,7 @@ public function unwrapOr($optb)
      */
     public function unwrapOrElse(Closure $op)
     {
-        return $op($this->err);
+        return $op($this->err, ...$this->pass);
     }
 
     /**
@@ -231,4 +238,17 @@ public function err(): Option
     {
         return new Some($this->err);
     }
+
+    /**
+     * The attached pass-through args will be unpacked into extra args into chained closures
+     *
+     * @param array ...$args
+     * @return Result
+     */
+    public function with(...$args): Result
+    {
+        $this->pass = $args;
+
+        return $this;
+    }
 }
diff --git a/src/Result/Ok.php b/src/Result/Ok.php
@@ -26,14 +26,21 @@ class Ok implements Result
      */
     private $value;
 
+    /**
+     * @var array
+     */
+    private $pass;
+
     /**
      * Ok constructor.
      *
      * @param mixed $value
+     * @param array ...$pass
      */
-    public function __construct($value)
+    public function __construct($value, ...$pass)
     {
         $this->value = $value;
+        $this->pass = $pass;
     }
 
     /**
@@ -64,7 +71,7 @@ public function isErr(): bool
      */
     public function map(Closure $mapper): Result
     {
-        return new self($mapper($this->value));
+        return new self($mapper($this->value, ...$this->pass));
     }
 
     /**
@@ -109,7 +116,7 @@ public function and(Result $res): Result
      */
     public function andThen(Closure $op): Result
     {
-        $result = $op($this->value);
+        $result = $op($this->value, ...$this->pass);
 
         if (!($result instanceof Result)) {
             throw new ResultException("Op must return a Result");
@@ -238,4 +245,17 @@ public function err(): Option
     {
         return new None;
     }
+
+    /**
+     * The attached pass-through args will be unpacked into extra args into chained closures
+     *
+     * @param array ...$args
+     * @return Result
+     */
+    public function with(...$args): Result
+    {
+        $this->pass = $args;
+
+        return $this;
+    }
 }