Refined new exceptions; added NotImplementedException

also fixed some coding style issues

src/Smalot/PdfParser/Exception/EmptyPdfException.php

@@ -1,7 +1,12 @@
-<?php declare(strict_types = 1);
+<?php
+
+declare(strict_types=1);
 
 namespace Smalot\PdfParser\Exception;
 
+/**
+ * This Exception is thrown when no PDF data was given.
+ */
 class EmptyPdfException extends \Exception
 {
 }

src/Smalot/PdfParser/Exception/MissingPdfHeaderException.php

@@ -1,7 +1,12 @@
-<?php declare(strict_types = 1);
+<?php
+
+declare(strict_types=1);
 
 namespace Smalot\PdfParser\Exception;
 
+/**
+ * This Exception is thrown when the %PDF- header is missing.
+ */
 class MissingPdfHeaderException extends \Exception
 {
 }

src/Smalot/PdfParser/Exception/NotImplementedException.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Smalot\PdfParser\Exception;
+
+/**
+ * This Exception is thrown when a functionality has not yet been implemented.
+ */
+class NotImplementedException extends \Exception
+{
+}

src/Smalot/PdfParser/RawData/FilterHelper.php

@@ -42,6 +42,8 @@
 
 namespace Smalot\PdfParser\RawData;
 
+use Smalot\PdfParser\Exception\NotImplementedException;
+
 class FilterHelper
 {
     protected $availableFilters = ['ASCIIHexDecode', 'ASCII85Decode', 'LZWDecode', 'FlateDecode', 'RunLengthDecode'];
@@ -54,7 +56,8 @@ class FilterHelper
      *
      * @return string Decoded data string
      *
-     * @throws \Exception if a certain decode function is not implemented yet
+     * @throws \Exception
+     * @throws \Smalot\PdfParser\Exception\NotImplementedException if a certain decode function is not implemented yet
      */
     public function decodeFilter(string $filter, string $data, int $decodeMemoryLimit = 0): string
     {
@@ -75,15 +78,15 @@ public function decodeFilter(string $filter, string $data, int $decodeMemoryLimi
                 return $this->decodeFilterRunLengthDecode($data);
 
             case 'CCITTFaxDecode':
-                throw new \Exception('Decode CCITTFaxDecode not implemented yet.');
+                throw new NotImplementedException('Decode CCITTFaxDecode not implemented yet.');
             case 'JBIG2Decode':
-                throw new \Exception('Decode JBIG2Decode not implemented yet.');
+                throw new NotImplementedException('Decode JBIG2Decode not implemented yet.');
             case 'DCTDecode':
-                throw new \Exception('Decode DCTDecode not implemented yet.');
+                throw new NotImplementedException('Decode DCTDecode not implemented yet.');
             case 'JPXDecode':
-                throw new \Exception('Decode JPXDecode not implemented yet.');
+                throw new NotImplementedException('Decode JPXDecode not implemented yet.');
             case 'Crypt':
-                throw new \Exception('Decode Crypt not implemented yet.');
+                throw new NotImplementedException('Decode Crypt not implemented yet.');
             default:
                 return $data;
         }

src/Smalot/PdfParser/RawData/RawDataParser.php

@@ -43,8 +43,8 @@
 namespace Smalot\PdfParser\RawData;
 
 use Smalot\PdfParser\Config;
-use Smalot\PdfParser\Exception\MissingPdfHeaderException;
 use Smalot\PdfParser\Exception\EmptyPdfException;
+use Smalot\PdfParser\Exception\MissingPdfHeaderException;
 
 class RawDataParser
 {