Changed to using an error handler for the scope parser

lib/Scope/Data.php

@@ -13,7 +13,7 @@ class Data {
     protected int $endPosition;
 
     public function __construct(string $data) {
-        preg_match_all('/[BLR]:|[A-Za-z0-9-+_\*\.]+|[\,\|\-\(\)&]/', $data, $matches);
+        preg_match_all('/[BLR]:|[A-Za-z0-9-+_\*\.]+|[\,\|\-\(\)&]/', $data, $matches, PREG_OFFSET_CAPTURE);
         $this->data = $matches[0] ?? [];
         $this->endPosition = count($this->data) - 1;
     }
@@ -23,24 +23,23 @@ class Data {
             return false;
         }
 
-        return $this->data[++$this->_position];
+        return $this->data[++$this->_position][0];
     }
 
-    public function peek(): string|bool {
-        if ($this->_position === $this->endPosition) {
+    public function offset(): int|bool {
+        if ($this->_position > $this->endPosition) {
             return false;
         }
 
-        return $this->data[$this->_position + 1];
+        return $this->data[$this->_position][1];
     }
 
-    public function unconsume(): bool {
-        if ($this->_position < 0) {
+    public function peek(): string|bool {
+        if ($this->_position === $this->endPosition) {
             return false;
         }
 
-        $this->_position--;
-        return true;
+        return $this->data[$this->_position + 1][0];
     }
 
     public function __get(string $name) {

lib/Scope/Exception.php

@@ -1,36 +0,0 @@
-<?php
-/** @license MIT
- * Copyright 2021 Dustin Wilson et al.
- * See LICENSE and AUTHORS files for details */
-
-declare(strict_types=1);
-namespace dW\Highlighter\Scope;
-
-class Exception extends \Exception {
-    const MESSAGE = '%s expected; found %s';
-
-    public function __construct(array|string $expected, string|bool $found) {
-        if (!is_string($expected)) {
-            $expectedLen = count($expected);
-            if ($expectedLen === 1) {
-                $expected = ($expected[0] !== false) ? $expected[0] : 'end of input';
-            } else {
-                $temp = [];
-                for ($i = 0; $i < $strlen; $i++) {
-                    $temp[] = ($expected[$i] !== false) ? "{$expected[$i]}" : 'end of input';
-                }
-                $expected = $temp;
-
-                if ($expectedLen > 2) {
-                    $last = array_pop($expected);
-                    $expected = implode(', ', $expected) . ', or ' . $last;
-                } else {
-                    $expected = implode(' or ', $expected);
-                }
-            }
-        }
-
-        $found = ($found !== false) ? "\"$found\"" : 'end of input';
-        parent::__construct(sprintf(self::MESSAGE, $expected, $found), 2112);
-    }
-}

lib/Scope/ParseError.php

@@ -0,0 +1,47 @@
+<?php
+/** @license MIT
+ * Copyright 2017 , Dustin Wilson, J. King et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace dW\Highlighter\Scope;
+
+class ParseError {
+    const MESSAGE = 'Highlighter Scope Parse Error: %s expected; found %s at offset %s';
+
+    public static function clearHandler() {
+        restore_error_handler();
+    }
+
+    public static function errorHandler(int $code, string $message) {
+        echo "$message\n";
+    }
+
+    public static function setHandler() {
+        set_error_handler([__CLASS__, 'errorHandler'], \E_USER_ERROR);
+    }
+
+    public static function trigger(array|string $expected, string|bool $found, int $offset) {
+        if (!is_string($expected)) {
+            $expectedLen = count($expected);
+            if ($expectedLen === 1) {
+                $expected = ($expected[0] !== false) ? $expected[0] : 'end of input';
+            } else {
+                $expected = array_map(function($n) {
+                    $n = ($n !== false) ? $n : 'end of input';
+                }, $expected);
+
+                if ($expectedLen > 2) {
+                    $last = array_pop($expected);
+                    $expected = implode(', ', $expected) . ', or ' . $last;
+                } else {
+                    $expected = implode(' or ', $expected);
+                }
+            }
+        }
+
+        $found = ($found !== false) ? "\"$found\"" : 'end of input';
+        trigger_error(sprintf(self::MESSAGE, $expected, $found, $offset), \E_USER_ERROR);
+        exit(1);
+    }
+}

lib/Scope/Parser.php

@@ -13,12 +13,24 @@ class Parser {
     protected int $debugCount = 1;
 
     protected static Parser $instance;
-    protected const SCOPE_REGEX = '/^[A-Za-z0-9-+_\.\*]+$/S';
 
 
     public static function parse(string $selector): Matcher|false {
         self::$instance = new self($selector);
-        return self::parseSelector();
+
+        $errorReporting = false;
+        if ((error_reporting() & \E_USER_ERROR)) {
+            $errorReporting = true;
+            ParseError::setHandler();
+        }
+
+        $result = self::parseSelector();
+
+        if ($errorReporting) {
+            ParseError::clearHandler();
+        }
+
+        return $result;
     }
 
 
@@ -75,19 +87,20 @@ class Parser {
 
         $peek = self::$instance->data->peek();
         $prefix = null;
-        if (in_array($peek[0], [ 'B', 'L', 'R' ]) && $peek[1] === ':') {
+        if ($peek !== false && in_array($peek[0], [ 'B', 'L', 'R' ]) && $peek[1] === ':') {
             $prefix = $peek[0];
             self::$instance->data->consume();
+            $peek = self::$instance->data->peek();
         }
 
-        $peek = self::$instance->data->peek();
         if ($peek === '(') {
             self::$instance->data->consume();
             $result = self::parseGroup($prefix);
-        } elseif (preg_match(self::SCOPE_REGEX, $peek)) {
+        } elseif (strspn($peek, 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-+_.*') === strlen($peek)) {
             $result = self::parsePath($prefix);
         } else {
-            throw new Exception([ 'Instance of ' . __NAMESPACE__ . 'GroupMatcher', 'Instance of ' . __NAMESPACE__ . 'PathMatcher' ], $peek);
+            // TODO: Take the effort to make this more descriptive
+            self::error([ 'Group', 'Path' ], $peek);
         }
 
         if (self::$debug) {
@@ -105,7 +118,7 @@ class Parser {
         $result = self::parseSelector();
         $token = self::$instance->data->consume();
         if ($token !== ')') {
-            throw new Exception(')', $token);
+            self::error('")"', $token);
         }
 
         $result = ($prefix === null) ? $result : new GroupMatcher($prefix, $result);
@@ -126,7 +139,7 @@ class Parser {
         $result[] = self::parseScope();
 
         $peek = self::$instance->data->peek();
-        while (!in_array($peek, [ '-', false ]) && preg_match(self::SCOPE_REGEX, $peek)) {
+        while (!in_array($peek, [ '-', false ]) && strspn($peek, 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-+_.*') === strlen($peek)) {
             $result[] = self::parseScope();
             $peek = self::$instance->data->peek();
         }
@@ -172,7 +185,7 @@ class Parser {
         $token = self::$instance->data->consume();
         if ($token === false || !preg_match('/^(?:[A-Za-z0-9-_]+|\*)(?:\.(?:[A-Za-z0-9-+_]+|\*))*$/S', $token)) {
             // TODO: Take the effort to make this more descriptive
-            throw new Exception('valid scope syntax', $token);
+            self::error('valid scope syntax', $token);
         }
 
         $segments = explode('.', $token);
@@ -220,4 +233,8 @@ class Parser {
             debug_backtrace()[1]['function'],
             str_replace([ '::__set_state(array', __NAMESPACE__ ], '', var_export($result, true)));
     }
+
+    protected static function error(array|string $expected, string|bool $found) {
+        ParseError::trigger($expected, $found, self::$instance->data->offset());
+    }
 }