Add Markdown Environment and Extensions support

README.md

@@ -43,6 +43,12 @@ function render(string $markdown): string {
 
   return $html;
 }
+
+// or simply
+
+function render(string $markdown): string {
+  return Markdown\Environment::html()->convert($markdown);
+}
 ```
 
 For complete compatibility with GitHub Flavored Markdown, support for embedded HTML must be enabled; it is disabled
@@ -51,6 +57,12 @@ by default as a security precaution.
 ```Hack
 $ctx = (new Markdown\ParserContext())->enableHTML_UNSAFE();
 $ast = Markdown\parse($ctx, $markdown);
+
+// using `Facebook\Markdown\Environment`
+
+$unsafe = true;
+$environment = Markdown\Environment::html($unsafe);
+$ast = $environment->parse($markdown);
 ```
 
 If you are re-using contexts to render multiple independent snippets, you will need to call `->resetFileData()` on the context.

src/Environment.php

@@ -0,0 +1,99 @@
+<?hh // strict
+/*
+ *  Copyright (c) 2004-present, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the MIT license found in the
+ *  LICENSE file in the root directory of this source tree.
+ *
+ */
+
+namespace Facebook\Markdown;
+
+final class Environment<T> {
+  public function __construct(
+    private ParserContext $parser,
+    private RenderContext $context,
+    private Renderer<T> $renderer,
+  ) {}
+
+  public static function html(bool $unsafe = false): Environment<string> {
+    $parser = new ParserContext();
+    $context = new RenderContext();
+    $renderer = new HTMLRenderer($context);
+
+    if ($unsafe) {
+        $parser->enableHTML_UNSAFE();
+    }
+
+    return new self($parser, $context, $renderer);
+  }
+
+  public function setParser(ParserContext $parser): void {
+    $this->parser = $parser;
+  }
+
+  public function getParser(): ParserContext {
+    return $this->parser;
+  }
+
+  public function setContext(RenderContext $context): void {
+    $this->context = $context;
+  }
+
+  public function getContext(): RenderContext {
+    return $this->context;
+  }
+
+  public function setRenderer(Renderer<T> $renderer): void {
+    $this->renderer = $renderer;
+  }
+
+  public function getRenderer(): Renderer<T> {
+    return $this->renderer;
+  }
+
+  public function setInlineContext(Inlines\Context $context): void {
+    $this->parser->setInlineContext($context);
+  }
+
+  public function getInlineContext(): Inlines\Context {
+    return $this->parser->getInlineContext();
+  }
+
+  public function setBlockContext(UnparsedBlocks\Context $context): void {
+    $this->parser->setBlockContext($context);
+  }
+
+  public function getBlockContext(): UnparsedBlocks\Context {
+    return $this->parser->getBlockContext();
+  }
+
+  public function getFilters(): Container<RenderFilter> {
+    return $this->context->getFilters();
+  }
+
+  public function addFilters(RenderFilter ...$filters): void {
+    $this->context->appendFilters(...$filters);
+  }
+
+  public function use(Extension $extension): void {
+    $this->getBlockContext()
+      ->prependBlockTypes(...$extension->getBlockProducers());
+    $this->getInlineContext()
+      ->prependInlineTypes(...$extension->getInlineTypes());
+    $this->addFilters(...$extension->getRenderFilters());
+  }
+
+  public function parse(string $markdown): ASTNode {
+    return parse($this->parser, $markdown);
+  }
+
+  public function render(ASTNode $markdown): T {
+    return $this->renderer->render($markdown);
+  }
+
+  public function convert(string $markdown): T {
+    return $this->render($this->parse($markdown));
+  }
+}

src/Extension.php

@@ -0,0 +1,34 @@
+<?hh // strict
+/*
+ *  Copyright (c) 2004-present, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the MIT license found in the
+ *  LICENSE file in the root directory of this source tree.
+ *
+ */
+
+namespace Facebook\Markdown;
+
+abstract class Extension {
+  /**
+   * @see Facebook\Markdown\RenderContext::appendFilters()
+   */
+  public function getRenderFilters(): Container<RenderFilter> {
+    return vec[];
+  }
+
+  /**
+   * @see Facebook\Markdown\Inlines\Context::prependInlineTypes()
+   */
+  public function getInlineTypes(): Container<classname<Inlines\Inline>> {
+    return vec[];
+  }
+
+  /**
+   * @see Facebook\Markdown\UnparsedBlocks\Context::prependBlockTypes()
+   */
+  public function getBlockProducers(): Container<classname<UnparsedBlocks\BlockProducer>> {
+    return vec[];
+  }
+}