more readable code

1 files changed, 35 insertions, 23 deletions

diff --git a/lib/ereg.php b/lib/ereg.php
index 4feb5e4..1f1ee07 100644
--- a/lib/ereg.php
+++ b/lib/ereg.php
@@ -3,50 +3,62 @@ namespace {
     if (!function_exists('ereg')) {
         function ereg($pattern, $subject, &$matches = array())
         {
-            foreach (array('/', '@', '#', '%', '±') as $boundary)
-            if (false === strpos($pattern, $boundary)) { 
-                return preg_match($boundary.$pattern.$boundary, $subject, $matches);
-            }
+            $boundary = _ereg_determine_boundary($pattern);
+            return preg_match($boundary . $pattern . $boundary, $subject, $matches);
         }
 
         function eregi($pattern, $subject, &$matches = array())
         {
-            foreach (array('/', '@', '#', '%', '±') as $boundary)
-            if (false === strpos($pattern, $boundary)) { 
-                return preg_match($boundary.$pattern.$boundary.'i', $subject, $matches);
-            }
+            $boundary = _ereg_determine_boundary($pattern);
+            return preg_match($boundary . $pattern . $boundary . 'i', $subject, $matches);
         }
 
         function ereg_replace($pattern, $replacement, $string)
         {
-            foreach (array('/', '@', '#', '%', '±') as $boundary)
-            if (false === strpos($pattern, $boundary)) { 
-                return preg_replace($boundary.$pattern.$boundary, $replacement, $string);
-            }
+            $boundary = _ereg_determine_boundary($pattern);
+            return preg_replace($boundary . $pattern . $boundary, $replacement, $string);
         }
 
         function eregi_replace($pattern, $replacement, $string)
         {
-            foreach (array('/', '@', '#', '%', '±') as $boundary)
-            if (false === strpos($pattern, $boundary)) { 
-                return preg_replace($boundary.$pattern.$boundary.'i', $replacement, $string);
-            }
+            $boundary = _ereg_determine_boundary($pattern);
+            return preg_replace($boundary . $pattern . $boundary . 'i', $replacement, $string);
         }
 
         function split($pattern, $subject, $limit = -1)
         {
-            foreach (array('/', '@', '#', '%', '±') as $boundary)
-            if (false === strpos($pattern, $boundary)) { 
-                return preg_split($boundary.$pattern.$boundary, $subject, $limit);
-            }
+            $boundary = _ereg_determine_boundary($pattern);
+            return preg_split($boundary . $pattern . $boundary, $subject, $limit);
         }
 
         function spliti($pattern, $subject, $limit = -1)
         {
-            foreach (array('/', '@', '#', '%', '±') as $boundary)
-            if (false === strpos($pattern, $boundary)) { 
-                return preg_split($boundary.$pattern.$boundary.'i', $subject, $limit);
+            $boundary = _ereg_determine_boundary($pattern);
+            return preg_split($boundary . $pattern . $boundary . 'i', $subject, $limit);
+        }
+
+        /**
+         * @method _ereg_determine_boundary Prepare the pattern and determine a valid boundary. 
+         * 
+         * @var string $pattern The possibly escaped pattern to match for. 
+         * @return string a suitable RegEx boundary
+         * 
+         * One would suggest just using preg_quote, but perhaps the pattern already is quoted, and therefore 
+         * using preg_quote would just double-quote and with that ruin the pattern.  
+         * The trick here is to find a boundary that is not within the pattern. 
+         * I have contemplated using "any ASCII charachter" but that would require detecting character classes
+         * and that's just too complicated.  
+         * The chance that all of these boundaries will conflict, and if so; new ones can be added :)
+         */
+        function _ereg_determine_boundary($pattern) 
+        {
+            foreach (array('/', '@', '#', '%', '±') as $boundary) {
+                if (false === strpos($pattern, $boundary)) { 
+                    return $boundary;
+                }
             }
+
+            throw new Exception("Very sorry, could not shim the regular expression. Please follow the debug trace two steps back to see where the incompatible ereg-style function call is made.");
         }
     }
 }