From 3698f4b727ae18831fb3400b6eeab42dc16b1faf Mon Sep 17 00:00:00 2001
From: Nikita Popov <nikita.ppv@gmail.com>
Date: Sat, 1 Aug 2020 22:02:52 +0200
Subject: [PATCH] Add common KeywordEmulator

The logic for keyword emulation is always going to be the same.
---
 .../Lexer/TokenEmulator/FnTokenEmulator.php   | 40 +++------------
 .../Lexer/TokenEmulator/KeywordEmulator.php   | 50 +++++++++++++++++++
 .../TokenEmulator/MatchTokenEmulator.php      | 38 ++------------
 3 files changed, 61 insertions(+), 67 deletions(-)
 create mode 100644 lib/PhpParser/Lexer/TokenEmulator/KeywordEmulator.php

diff --git a/lib/PhpParser/Lexer/TokenEmulator/FnTokenEmulator.php b/lib/PhpParser/Lexer/TokenEmulator/FnTokenEmulator.php
index 3b47dac..92f72f2 100644
--- a/lib/PhpParser/Lexer/TokenEmulator/FnTokenEmulator.php
+++ b/lib/PhpParser/Lexer/TokenEmulator/FnTokenEmulator.php
@@ -4,48 +4,20 @@ namespace PhpParser\Lexer\TokenEmulator;
 
 use PhpParser\Lexer\Emulative;
 
-final class FnTokenEmulator implements TokenEmulatorInterface
+final class FnTokenEmulator extends KeywordEmulator
 {
     public function getPhpVersion(): string
     {
         return Emulative::PHP_7_4;
     }
 
-    public function isEmulationNeeded(string $code): bool
+    public function getKeywordString(): string
     {
-        return strpos($code, 'fn') !== false;
+        return 'fn';
     }
 
-    public function emulate(string $code, array $tokens): array
+    public function getKeywordToken(): int
     {
-        foreach ($tokens as $i => $token) {
-            if ($token[0] === T_STRING && strtolower($token[1]) === 'fn') {
-                $previousNonSpaceToken = $this->getPreviousNonSpaceToken($tokens, $i);
-                if ($previousNonSpaceToken !== null && $previousNonSpaceToken[0] === T_OBJECT_OPERATOR) {
-                    continue;
-                }
-
-                $tokens[$i][0] = Emulative::T_FN;
-            }
-        }
-
-        return $tokens;
+        return Emulative::T_FN;
     }
-
-    /**
-     * @param mixed[] $tokens
-     * @return mixed[]|null
-     */
-    private function getPreviousNonSpaceToken(array $tokens, int $start)
-    {
-        for ($i = $start - 1; $i >= 0; --$i) {
-            if ($tokens[$i][0] === T_WHITESPACE) {
-                continue;
-            }
-
-            return $tokens[$i];
-        }
-
-        return null;
-    }
-}
+}
\ No newline at end of file
diff --git a/lib/PhpParser/Lexer/TokenEmulator/KeywordEmulator.php b/lib/PhpParser/Lexer/TokenEmulator/KeywordEmulator.php
new file mode 100644
index 0000000..84296aa
--- /dev/null
+++ b/lib/PhpParser/Lexer/TokenEmulator/KeywordEmulator.php
@@ -0,0 +1,50 @@
+<?php declare(strict_types=1);
+
+namespace PhpParser\Lexer\TokenEmulator;
+
+use PhpParser\Lexer\Emulative;
+
+abstract class KeywordEmulator implements TokenEmulatorInterface
+{
+    abstract function getKeywordString(): string;
+    abstract function getKeywordToken(): int;
+
+    public function isEmulationNeeded(string $code): bool
+    {
+        return strpos($code, $this->getKeywordString()) !== false;
+    }
+
+    public function emulate(string $code, array $tokens): array
+    {
+        $keywordString = $this->getKeywordString();
+        foreach ($tokens as $i => $token) {
+            if ($token[0] === T_STRING && strtolower($token[1]) === $keywordString) {
+                $previousNonSpaceToken = $this->getPreviousNonSpaceToken($tokens, $i);
+                if ($previousNonSpaceToken !== null && $previousNonSpaceToken[0] === T_OBJECT_OPERATOR) {
+                    continue;
+                }
+
+                $tokens[$i][0] = $this->getKeywordToken();
+            }
+        }
+
+        return $tokens;
+    }
+
+    /**
+     * @param mixed[] $tokens
+     * @return mixed[]|null
+     */
+    private function getPreviousNonSpaceToken(array $tokens, int $start)
+    {
+        for ($i = $start - 1; $i >= 0; --$i) {
+            if ($tokens[$i][0] === T_WHITESPACE) {
+                continue;
+            }
+
+            return $tokens[$i];
+        }
+
+        return null;
+    }
+}
diff --git a/lib/PhpParser/Lexer/TokenEmulator/MatchTokenEmulator.php b/lib/PhpParser/Lexer/TokenEmulator/MatchTokenEmulator.php
index 83c8ed2..a295052 100644
--- a/lib/PhpParser/Lexer/TokenEmulator/MatchTokenEmulator.php
+++ b/lib/PhpParser/Lexer/TokenEmulator/MatchTokenEmulator.php
@@ -4,48 +4,20 @@ namespace PhpParser\Lexer\TokenEmulator;
 
 use PhpParser\Lexer\Emulative;
 
-final class MatchTokenEmulator implements TokenEmulatorInterface
+final class MatchTokenEmulator extends KeywordEmulator
 {
     public function getPhpVersion(): string
     {
         return Emulative::PHP_8_0;
     }
 
-    public function isEmulationNeeded(string $code): bool
+    public function getKeywordString(): string
     {
-        return strpos($code, 'match') !== false;
+        return 'match';
     }
 
-    public function emulate(string $code, array $tokens): array
+    public function getKeywordToken(): int
     {
-        foreach ($tokens as $i => $token) {
-            if ($token[0] === T_STRING && strtolower($token[1]) === 'match') {
-                $previousNonSpaceToken = $this->getPreviousNonSpaceToken($tokens, $i);
-                if ($previousNonSpaceToken !== null && $previousNonSpaceToken[0] === T_OBJECT_OPERATOR) {
-                    continue;
-                }
-
-                $tokens[$i][0] = Emulative::T_MATCH;
-            }
-        }
-
-        return $tokens;
-    }
-
-    /**
-     * @param mixed[] $tokens
-     * @return mixed[]|null
-     */
-    private function getPreviousNonSpaceToken(array $tokens, int $start)
-    {
-        for ($i = $start - 1; $i >= 0; --$i) {
-            if ($tokens[$i][0] === T_WHITESPACE) {
-                continue;
-            }
-
-            return $tokens[$i];
-        }
-
-        return null;
+        return Emulative::T_MATCH;
     }
 }