[RFC] Add PreLexerInterface

src/Environment.php

@@ -56,6 +56,8 @@ class Environment
     private $autoReload;
     private $cache;
     private $lexer;
+    /** @var array<PreLexerInterface> */
+    private $preLexers = [];
     private $parser;
     private $compiler;
     /** @var array<string, mixed> */
@@ -488,6 +490,11 @@ public function resolveTemplate($names): TemplateWrapper
         throw new LoaderError(\sprintf('Unable to find one of the following templates: "%s".', implode('", "', $names)));
     }
 
+    public function addPreLexer(PreLexerInterface $preLexer): void
+    {
+        $this->preLexers[] = $preLexer;
+    }
+
     public function setLexer(Lexer $lexer)
     {
         $this->lexer = $lexer;
@@ -502,6 +509,10 @@ public function tokenize(Source $source): TokenStream
             $this->lexer = new Lexer($this);
         }
 
+        foreach ($this->preLexers as $preLexer) {
+            $source = $preLexer->preLex($source);
+        }
+
         return $this->lexer->tokenize($source);
     }
 

src/PreLexerInterface.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Twig;
+
+interface PreLexerInterface
+{
+    public function preLex(Source $source): Source;
+}