diff --git a/src/parser/PhutilEditorConfig.php b/src/parser/PhutilEditorConfig.php
index 1eb7a5f..c87e251 100644
--- a/src/parser/PhutilEditorConfig.php
+++ b/src/parser/PhutilEditorConfig.php
@@ -1,180 +1,195 @@
 <?php
 
 /**
  * Parser for [[http://editorconfig.org/ | EditorConfig]] files.
  */
 final class PhutilEditorConfig {
 
+  const CHARSET             = 'charset';
+  const END_OF_LINE         = 'end_of_line';
+  const INDENT_SIZE         = 'indent_size';
+  const INDENT_STYLE        = 'indent_style';
+  const FINAL_NEWLINE       = 'insert_final_newline';
+  const LINE_LENGTH         = 'max_line_length';
+  const TAB_WIDTH           = 'tab_width';
+  const TRAILING_WHITESPACE = 'trim_trailing_whitespace';
+
   /**
    * Valid properties.
    *
    * See http://editorconfig.org/#file-format-details.
    */
   private static $knownProperties = array(
-    'charset' => array('latin1', 'utf-8', 'utf-8-bom', 'utf-16be', 'utf-16le'),
-    'end_of_line' => array('lf', 'cr', 'crlf'),
-    'indent_size' => 'int|string',
-    'indent_style' => array('space', 'tab'),
-    'insert_final_newline' => 'bool',
-    'max_line_length' => 'int',
-    'tab_width' => 'int',
-    'trim_trailing_whitespace' => 'bool',
+    self::CHARSET => array(
+      'latin1',
+      'utf-8',
+      'utf-8-bom',
+      'utf-16be',
+      'utf-16le',
+    ),
+    self::END_OF_LINE => array('lf', 'cr', 'crlf'),
+    self::INDENT_SIZE => 'int|string',
+    self::INDENT_STYLE => array('space', 'tab'),
+    self::FINAL_NEWLINE => 'bool',
+    self::LINE_LENGTH => 'int',
+    self::TAB_WIDTH => 'int',
+    self::TRAILING_WHITESPACE => 'bool',
   );
 
   private $root;
 
   /**
    * Constructor.
    *
    * @param string  The root directory.
    */
   public function __construct($root) {
     $this->root = $root;
   }
 
   /**
    * Get the specified EditorConfig property for the specified path.
    *
    * @param  string
    * @param  string
    * @return wild
    */
   public function getProperty($path, $key) {
     if (!idx(self::$knownProperties, $key)) {
       throw new InvalidArgumentException(pht('Invalid EditorConfig property.'));
     }
 
     $props = $this->getProperties($path);
 
     switch ($key) {
-      case 'indent_size':
-        if (idx($props, 'indent_size') === null &&
-            idx($props, 'indent_style') === 'tab') {
+      case self::INDENT_SIZE:
+        if (idx($props, self::INDENT_SIZE) === null &&
+            idx($props, self::INDENT_STYLE) === 'tab') {
           return 'tab';
-        } else if (idx($props, 'indent_size') === 'tab' &&
-                   idx($props, 'tab_width') === null) {
-          return idx($props, 'tab_width');
+        } else if (idx($props, self::INDENT_SIZE) === 'tab' &&
+                   idx($props, self::TAB_WIDTH) === null) {
+          return idx($props, self::TAB_WIDTH);
         }
         break;
 
-      case 'tab_width':
-        if (idx($props, 'tab_width') === null &&
-            idx($props, 'indent_size') !== null &&
-            idx($props, 'indent_size') !== 'tab') {
-          return idx($props, 'indent_size');
+      case self::TAB_WIDTH:
+        if (idx($props, self::TAB_WIDTH) === null &&
+            idx($props, self::INDENT_SIZE) !== null &&
+            idx($props, self::INDENT_SIZE) !== 'tab') {
+          return idx($props, self::INDENT_SIZE);
         }
         break;
     }
 
     return idx($props, $key);
   }
 
   /**
    * Get the EditorConfig properties for the specified path.
    *
    * Returns a map containing all of the EditorConfig properties which apply
    * to the specified path. The following rules are applied when processing
    * EditorConfig files:
    *
    * - If a glob does not contain `/`, it can match a path in any subdirectory.
    * - If the first character of a glob is `/`, it will only match files in the
    *   same directory as the `.editorconfig` file.
    * - Properties and values are case-insensitive.
    * - Unknown properties will be silently ignored.
    * - Values are not validated against the specification (this may change in
    *   the future).
    * - Invalid glob patterns will be silently ignored.
    *
    * @param  string
    * @return map<string, wild>
    */
   public function getProperties($path) {
     $configs = $this->getEditorConfigs($path);
     $matches = array();
 
     foreach ($configs as $config) {
       list($path_prefix, $editorconfig) = $config;
 
       foreach ($editorconfig as $glob => $properties) {
         if (!$glob) {
           continue;
         }
 
         if (strpos($glob, '/') === false) {
           $glob = '**/'.$glob;
         } else if (strncmp($glob, '/', 0)) {
           $glob = substr($glob, 1);
         }
 
         $glob = $path_prefix.'/'.$glob;
         try {
           if (!phutil_fnmatch($glob, $path)) {
             continue;
           }
         } catch (Exception $ex) {
           // Invalid glob pattern... ignore it.
           continue;
         }
 
         foreach ($properties as $property => $value) {
           $property = strtolower($property);
 
           if (!idx(self::$knownProperties, $property)) {
             // Unknown property... ignore it.
             continue;
           }
 
           if (is_string($value)) {
             $value = strtolower($value);
           }
           if ($value === '') {
             $value = null;
           }
           $matches[$property] = $value;
         }
       }
     }
 
     return $matches;
   }
 
   /**
    * Returns the EditorConfig files which affect the specified path.
    *
    * Find and parse all `.editorconfig` files between the specified path and
    * the root directory. The results are returned in the same order that they
    * should be matched.
    *
    * return list<pair<string, map>>
    */
   private function getEditorConfigs($path) {
     $configs    = array();
     $found_root = false;
     $root       = $this->root;
 
     do {
       $path = dirname($path);
       $file = $path.'/.editorconfig';
 
       if (!Filesystem::pathExists($file)) {
         continue;
       }
 
       $contents = Filesystem::readFile($file);
       $config = phutil_ini_decode($contents);
 
       if (idx($config, 'root') === true) {
         $found_root = true;
       }
       unset($config['root']);
       array_unshift($configs, array($path, $config));
 
       if ($found_root) {
         break;
       }
     } while ($path != $root && Filesystem::isDescendant($path, $root));
 
     return $configs;
   }
 
 }