fixing

classes/dataflow_lexer.php

@@ -0,0 +1,120 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+namespace tool_dataflows;
+
+use Symfony\Component\ExpressionLanguage\Token;
+use Symfony\Component\ExpressionLanguage\SyntaxError;
+use Symfony\Component\ExpressionLanguage\TokenStream;
+
+/**
+ * Class adding modification to Symfony Lexer to suit dataflow needs.
+ *
+ * @package    tool_dataflows
+ * @author     Ghaly Marc-Alexandre <marc-alexandreghaly@catalyst-ca.net>
+ * @copyright  Catalyst IT, 2023
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class dataflow_lexer extends \Symfony\Component\ExpressionLanguage\Lexer {
+    /**
+     * Tokenizes an expression.
+     *
+     * @param string $expression The expression to tokenize
+     *
+     * @return TokenStream A token stream instance
+     *
+     * @throws SyntaxError
+     */
+    public function tokenize($expression)
+    {
+        $expression = str_replace(["\r", "\n", "\t", "\v", "\f"], ' ', $expression);
+        $cursor = 0;
+        $tokens = [];
+        $brackets = [];
+        $end = \strlen($expression);
+
+        while ($cursor < $end) {
+            if (' ' == $expression[$cursor]) {
+                ++$cursor;
+
+                continue;
+            }
+
+            if (preg_match('/[0-9]+(?:\.[0-9]+)?/A', $expression, $match, 0, $cursor)) {
+                // Numbers.
+                // Floats.
+                $number = (float) $match[0];
+                if (preg_match('/^[0-9]+$/', $match[0]) && $number <= \PHP_INT_MAX) {
+                    // Integers lower than the maximum.
+                    $number = (int) $match[0];
+                }
+                $tokens[] = new Token(Token::NUMBER_TYPE, $number, $cursor + 1);
+                $cursor += \strlen($match[0]);
+            } elseif (preg_match("/{'(\W[a-zA-Z_\x7f-\xff][a-zA-Z0-9_.\x7f-\xff]*)'}/A", $expression, $match, 0, $cursor)) {
+                // Names litteral.
+                $tokens[] = new Token(Token::NAME_TYPE, $match[1], $cursor + 1);
+                $cursor += \strlen($match[0]);
+            } elseif (false !== strpos('([{', $expression[$cursor])) {
+                // Opening bracket.
+                $brackets[] = [$expression[$cursor], $cursor];
+
+                $tokens[] = new Token(Token::PUNCTUATION_TYPE, $expression[$cursor], $cursor + 1);
+                ++$cursor;
+            } elseif (false !== strpos(')]}', $expression[$cursor])) {
+                // Closing bracket.
+                if (empty($brackets)) {
+                    throw new SyntaxError(sprintf('Unexpected "%s".', $expression[$cursor]), $cursor, $expression);
+                }
+
+                list($expect, $cur) = array_pop($brackets);
+                if ($expression[$cursor] != strtr($expect, '([{', ')]}')) {
+                    throw new SyntaxError(sprintf('Unclosed "%s".', $expect), $cur, $expression);
+                }
+
+                $tokens[] = new Token(Token::PUNCTUATION_TYPE, $expression[$cursor], $cursor + 1);
+                ++$cursor;
+            } elseif (preg_match('/"([^"\\\\]*(?:\\\\.[^"\\\\]*)*)"|\'([^\'\\\\]*(?:\\\\.[^\'\\\\]*)*)\'/As', $expression, $match, 0, $cursor)) {
+                // Strings.
+                $tokens[] = new Token(Token::STRING_TYPE, stripcslashes(substr($match[0], 1, -1)), $cursor + 1);
+                $cursor += \strlen($match[0]);
+            } elseif (preg_match('/(?<=^|[\s(])not in(?=[\s(])|\!\=\=|(?<=^|[\s(])not(?=[\s(])|(?<=^|[\s(])and(?=[\s(])|\=\=\=|\>\=|(?<=^|[\s(])or(?=[\s(])|\<\=|\*\*|\.\.|(?<=^|[\s(])in(?=[\s(])|&&|\|\||(?<=^|[\s(])matches|\=\=|\!\=|\*|~|%|\/|\>|\||\!|\^|&|\+|\<|\-/A', $expression, $match, 0, $cursor)) {
+                // Operators.
+                $tokens[] = new Token(Token::OPERATOR_TYPE, $match[0], $cursor + 1);
+                $cursor += \strlen($match[0]);
+            } elseif (false !== strpos('.,?:', $expression[$cursor])) {
+                // Punctuation.
+                $tokens[] = new Token(Token::PUNCTUATION_TYPE, $expression[$cursor], $cursor + 1);
+                ++$cursor;
+            } elseif (preg_match('/[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*/A', $expression, $match, 0, $cursor)) {
+                // Names.
+                $tokens[] = new Token(Token::NAME_TYPE, $match[0], $cursor + 1);
+                $cursor += \strlen($match[0]);
+            } else {
+                // Unlexable.
+                throw new SyntaxError(sprintf('Unexpected character "%s".', $expression[$cursor]), $cursor, $expression);
+            }
+        }
+
+        $tokens[] = new Token(Token::EOF_TYPE, null, $cursor + 1);
+
+        if (!empty($brackets)) {
+            list($expect, $cur) = array_pop($brackets);
+            throw new SyntaxError(sprintf('Unclosed "%s".', $expect), $cur, $expression);
+        }
+
+        return new TokenStream($tokens, $expression);
+    }
+}

classes/parser.php

@@ -16,10 +16,10 @@
 
 namespace tool_dataflows;
 
+use tool_dataflows\dataflow_lexer;
 use Symfony\Component\Cache\Adapter\ApcuAdapter;
 use Symfony\Component\Cache\Adapter\FilesystemAdapter;
 use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
-use Symfony\Component\ExpressionLanguage\Lexer;
 use Symfony\Component\ExpressionLanguage\Node;
 use Symfony\Component\ExpressionLanguage\Token;
 use Symfony\Component\ExpressionLanguage\TokenStream;
@@ -80,9 +80,9 @@ private function __construct() {
      *
      * @return Lexer
      */
-    private function get_lexer(): Lexer {
+    private function get_lexer(): dataflow_lexer {
         if (is_null($this->lexer)) {
-            $this->lexer = new Lexer();
+            $this->lexer = new dataflow_lexer();
         }
         return $this->lexer;
     }

vendor/symfony/expression-language/ExpressionLanguage.php

@@ -15,6 +15,7 @@
 use Symfony\Component\Cache\Adapter\ArrayAdapter;
 use Symfony\Component\ExpressionLanguage\ParserCache\ParserCacheAdapter;
 use Symfony\Component\ExpressionLanguage\ParserCache\ParserCacheInterface;
+use tool_dataflows\dataflow_lexer;
 
 /**
  * Allows to compile and evaluate expressions written in your own DSL.
@@ -152,7 +153,7 @@ protected function registerFunctions()
     private function getLexer()
     {
         if (null === $this->lexer) {
-            $this->lexer = new Lexer();
+            $this->lexer = new dataflow_lexer();
         }
 
         return $this->lexer;

vendor/symfony/expression-language/Lexer.php

@@ -50,10 +50,6 @@ public function tokenize($expression)
                 }
                 $tokens[] = new Token(Token::NUMBER_TYPE, $number, $cursor + 1);
                 $cursor += \strlen($match[0]);
-            } elseif (preg_match("/{'(\W[a-zA-Z_\x7f-\xff][a-zA-Z0-9_.\x7f-\xff]*)'}/A", $expression, $match, 0, $cursor)) {
-                // names litteral
-                $tokens[] = new Token(Token::NAME_TYPE, $match[1], $cursor + 1);
-                $cursor += \strlen($match[0]);
             } elseif (false !== strpos('([{', $expression[$cursor])) {
                 // opening bracket
                 $brackets[] = [$expression[$cursor], $cursor];