community: Add PHP language parser to document_loaders (#19850)

**Description:**
Added a PHP language parser to document_loaders
**Issue:** N/A
**Dependencies:** N/A
**Twitter handle:** N/A

---------

Co-authored-by: Chester Curme <chester.curme@gmail.com>

docs/docs/modules/data_connection/document_transformers/code_splitter.ipynb

@@ -612,6 +612,63 @@
     "haskell_docs = haskell_splitter.create_documents([HASKELL_CODE])\n",
     "haskell_docs"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "4a11f7cd-cd85-430c-b307-5b5b5f07f8db",
+   "metadata": {},
+   "source": [
+    "## PHP\n",
+    "Here's an example using the PHP text splitter:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "90c66e7e-87a5-4a81-bece-7949aabf2369",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "[Document(page_content='<?php\\nnamespace foo;'),\n",
+       " Document(page_content='class Hello {'),\n",
+       " Document(page_content='public function __construct() { }\\n}'),\n",
+       " Document(page_content='function hello() {\\n    echo \"Hello World!\";\\n}'),\n",
+       " Document(page_content='interface Human {\\n    public function breath();\\n}'),\n",
+       " Document(page_content='trait Foo { }\\nenum Color\\n{\\n    case Red;'),\n",
+       " Document(page_content='case Blue;\\n}')]"
+      ]
+     },
+     "execution_count": 2,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "PHP_CODE = \"\"\"<?php\n",
+    "namespace foo;\n",
+    "class Hello {\n",
+    "    public function __construct() { }\n",
+    "}\n",
+    "function hello() {\n",
+    "    echo \"Hello World!\";\n",
+    "}\n",
+    "interface Human {\n",
+    "    public function breath();\n",
+    "}\n",
+    "trait Foo { }\n",
+    "enum Color\n",
+    "{\n",
+    "    case Red;\n",
+    "    case Blue;\n",
+    "}\"\"\"\n",
+    "php_splitter = RecursiveCharacterTextSplitter.from_language(\n",
+    "    language=Language.PHP, chunk_size=50, chunk_overlap=0\n",
+    ")\n",
+    "haskell_docs = php_splitter.create_documents([PHP_CODE])\n",
+    "haskell_docs"
+   ]
   }
  ],
  "metadata": {
@@ -630,7 +687,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.1"
+   "version": "3.10.4"
   }
  },
  "nbformat": 4,

libs/community/langchain_community/document_loaders/parsers/language/language_parser.py

@@ -18,6 +18,7 @@ from langchain_community.document_loaders.parsers.language.javascript import (
 from langchain_community.document_loaders.parsers.language.kotlin import KotlinSegmenter
 from langchain_community.document_loaders.parsers.language.lua import LuaSegmenter
 from langchain_community.document_loaders.parsers.language.perl import PerlSegmenter
+from langchain_community.document_loaders.parsers.language.php import PHPSegmenter
 from langchain_community.document_loaders.parsers.language.python import PythonSegmenter
 from langchain_community.document_loaders.parsers.language.ruby import RubySegmenter
 from langchain_community.document_loaders.parsers.language.rust import RustSegmenter
@@ -42,6 +43,7 @@ LANGUAGE_EXTENSIONS: Dict[str, str] = {
     "pl": "perl",
     "ts": "ts",
     "java": "java",
+    "php": "php",
 }
 
 LANGUAGE_SEGMENTERS: Dict[str, Any] = {
@@ -60,6 +62,7 @@ LANGUAGE_SEGMENTERS: Dict[str, Any] = {
     "perl": PerlSegmenter,
     "ts": TypeScriptSegmenter,
     "java": JavaSegmenter,
+    "php": PHPSegmenter,
 }
 
 Language = Literal[

libs/community/langchain_community/document_loaders/parsers/language/php.py

@@ -0,0 +1,35 @@
+from typing import TYPE_CHECKING
+
+from langchain_community.document_loaders.parsers.language.tree_sitter_segmenter import (  # noqa: E501
+    TreeSitterSegmenter,
+)
+
+if TYPE_CHECKING:
+    from tree_sitter import Language
+
+
+CHUNK_QUERY = """
+    [
+        (function_definition) @function
+        (class_declaration) @class
+        (interface_declaration) @interface
+        (trait_declaration) @trait
+        (enum_declaration) @enum
+        (namespace_definition) @namespace
+    ]
+""".strip()
+
+
+class PHPSegmenter(TreeSitterSegmenter):
+    """Code segmenter for PHP."""
+
+    def get_language(self) -> "Language":
+        from tree_sitter_languages import get_language
+
+        return get_language("php")
+
+    def get_chunk_query(self) -> str:
+        return CHUNK_QUERY
+
+    def make_line_comment(self, text: str) -> str:
+        return f"// {text}"

libs/community/tests/unit_tests/document_loaders/parsers/language/test_php.py

@@ -0,0 +1,68 @@
+import unittest
+
+import pytest
+
+from langchain_community.document_loaders.parsers.language.php import PHPSegmenter
+
+
+@pytest.mark.requires("tree_sitter", "tree_sitter_languages")
+class TestPHPSegmenter(unittest.TestCase):
+    def setUp(self) -> None:
+        self.example_code = """<?php
+namespace foo;
+
+class Hello {
+    public function __construct() { }
+}
+
+function hello() {
+    echo "Hello World!";
+}
+
+interface Human {
+    public function breath();
+}
+
+trait Foo { }
+
+enum Color
+{
+    case Red;
+    case Blue;
+}"""
+
+        self.expected_simplified_code = """<?php
+// Code for: namespace foo;
+
+// Code for: class Hello {
+
+// Code for: function hello() {
+
+// Code for: interface Human {
+
+// Code for: trait Foo { }
+
+// Code for: enum Color"""
+
+        self.expected_extracted_code = [
+            "namespace foo;",
+            "class Hello {\n    public function __construct() { }\n}",
+            'function hello() {\n    echo "Hello World!";\n}',
+            "interface Human {\n    public function breath();\n}",
+            "trait Foo { }",
+            "enum Color\n{\n    case Red;\n    case Blue;\n}",
+        ]
+
+    def test_is_valid(self) -> None:
+        self.assertTrue(PHPSegmenter("<?php $a = 0;").is_valid())
+        self.assertFalse(PHPSegmenter("<?php a ?b}+ c 1 2 3").is_valid())
+
+    def test_extract_functions_classes(self) -> None:
+        segmenter = PHPSegmenter(self.example_code)
+        extracted_code = segmenter.extract_functions_classes()
+        self.assertEqual(extracted_code, self.expected_extracted_code)
+
+    def test_simplify_code(self) -> None:
+        segmenter = PHPSegmenter(self.example_code)
+        simplified_code = segmenter.simplify_code()
+        self.assertEqual(simplified_code, self.expected_simplified_code)