add path value retrieval

Uri/Argument.php

@@ -322,6 +322,20 @@ final class Argument implements UriInterface
         return $this->pathElements[$pos + ($useOffset ? $this->pathOffset : 0)] ?? '';
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getPathKey(string $key) : string
+    {
+        foreach ($this->pathElements as $index => $element) {
+            if ($element === $key) {
+                return $this->pathElements[$index + 1] ?? '';
+            }
+        }
+
+        return '';
+    }
+
     /**
      * {@inheritdoc}
      */

Uri/HttpUri.php

@@ -391,6 +391,20 @@ final class HttpUri implements UriInterface
         return $this->pathElements[$pos + ($useOffset ? $this->pathOffset : 0)] ?? '';
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getPathKey(string $key) : string
+    {
+        foreach ($this->pathElements as $index => $element) {
+            if ($element === $key) {
+                return $this->pathElements[$index + 1] ?? '';
+            }
+        }
+
+        return '';
+    }
+
     /**
      * {@inheritdoc}
      */

Uri/UriInterface.php

@@ -128,6 +128,17 @@ interface UriInterface
      */
     public function getPathElement(int $pos = 0, bool $useOffset = true) : string;
 
+    /**
+     * Get the value after a key
+     *
+     * @param string $key Key to search for in path
+     *
+     * @return string
+     *
+     * @since 1.0.0
+     */
+    public function getPathKey(string $key) : string;
+
     /**
      * Get path elements.
      *