Merge pull request swiftlang#131 from google/format-markdown

Add `CommonMark` module for manipulating Markdown ASTs.

Author: allevato

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "Sources/CCommonMark/cmark"]
+	path = Sources/CCommonMark/cmark
+	url = https://github.com/apple/swift-cmark

Package.swift

@@ -40,11 +40,23 @@ let package = Package(
     .target(
       name: "Configuration",
       dependencies: []),
+    .target(name: "CommonMark", dependencies: ["CCommonMark"]),
+    .target(
+      name: "CCommonMark",
+      exclude: [
+        "cmark/api_test",
+        // We must exclude main.c or SwiftPM will treat this target as an
+        // executable target and we won't be able to import it from the
+        // CommonMark Swift module.
+        "cmark/src/main.c",
+      ]
+    ),
     .testTarget(
       name: "SwiftFormatTests",
       dependencies: ["Core", "Configuration", "Rules", "PrettyPrint", "SwiftSyntax"]),
     .testTarget(
       name: "PrettyPrinterTests",
       dependencies: ["Core", "Configuration", "Rules", "PrettyPrint", "SwiftSyntax"]),
+    .testTarget(name: "CommonMarkTests", dependencies: ["CommonMark"]),
   ]
 )

Sources/CCommonMark/cmark

@@ -0,0 +1,3 @@
+This directory contains hand-written versions of C headers for cmark that would
+normally be generated by CMake, and a module map that allows it to be imported
+from Swift. It is automatically added to clang's header search path by SwiftPM.

Sources/CCommonMark/include/README.md

@@ -0,0 +1,20 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Formatter open source project.
+//
+// Copyright (c) 2018 Apple Inc. and the Swift Formatter project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift Formatter project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CMARK_EXPORT_H
+#define CMARK_EXPORT_H
+
+#define CMARK_EXPORT
+
+#endif

Sources/CCommonMark/include/cmark_export.h

@@ -0,0 +1,21 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Formatter open source project.
+//
+// Copyright (c) 2018 Apple Inc. and the Swift Formatter project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift Formatter project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CMARK_VERSION_H
+#define CMARK_VERSION_H
+
+#define CMARK_VERSION ((0 << 16) | (22 << 8) | 0)
+#define CMARK_VERSION_STRING "0.22.0"
+
+#endif

Sources/CCommonMark/include/cmark_version.h

@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Formatter open source project.
+//
+// Copyright (c) 2018 Apple Inc. and the Swift Formatter project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift Formatter project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+#define HAVE_STDBOOL_H
+
+#ifdef HAVE_STDBOOL_H
+  #include <stdbool.h>
+#elif !defined(__cplusplus)
+  typedef char bool;
+#endif
+
+#define HAVE___BUILTIN_EXPECT
+
+#define HAVE___ATTRIBUTE__
+
+#ifdef HAVE___ATTRIBUTE__
+  #define CMARK_ATTRIBUTE(list) __attribute__ (list)
+#else
+  #define CMARK_ATTRIBUTE(list)
+#endif
+
+#ifndef CMARK_INLINE
+  #if defined(_MSC_VER) && !defined(__cplusplus)
+    #define CMARK_INLINE __inline
+  #else
+    #define CMARK_INLINE inline
+  #endif
+#endif

Sources/CCommonMark/include/config.h

@@ -0,0 +1,4 @@
+module CCommonMark {
+    header "../cmark/src/cmark.h"
+    export *
+}

Sources/CCommonMark/include/module.modulemap

@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Formatter open source project.
+//
+// Copyright (c) 2018 Apple Inc. and the Swift Formatter project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift Formatter project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+/// A Markdown node that represents block content; that is, content that occupies the full width of
+/// the viewport when rendered.
+///
+/// Examples of block content include paragraphs, block quotes, and code blocks.
+///
+/// At this time, the `BlockContent` protocol does not add any members of its own over what is
+/// already required by `MarkdownNode`. Instead, it is used as a means of enforcing containment
+/// relationships between nodes in the AST.
+public protocol BlockContent: MarkdownNode {}

Sources/CommonMark/BlockContent.swift

@@ -0,0 +1,52 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift Formatter open source project.
+//
+// Copyright (c) 2018 Apple Inc. and the Swift Formatter project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Swift Formatter project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+/// A block element that represents a long quotation, typically rendered in a callout box.
+public struct BlockQuoteNode: BlockContent {
+
+  /// The children of the receiver.
+  public let children: [BlockContent]
+
+  public let sourceRange: Range<SourceLocation>?
+
+  public var primitiveRepresentation: PrimitiveNode { return .blockQuote(self) }
+
+  /// Creates a new block quote node.
+  ///
+  /// - Parameters:
+  ///   - children: Block content nodes that are children of the new node.
+  ///   - sourceRange: The source range from which the node was parsed, if known.
+  public init(children: [BlockContent], sourceRange: Range<SourceLocation>? = nil) {
+    self.children = children
+    self.sourceRange = sourceRange
+  }
+
+  /// Returns a new node equivalent to the receiver, but whose children have been replaced with the
+  /// given list of nodes.
+  ///
+  /// - Parameter children: The new list of children.
+  /// - Returns: The new node.
+  public func replacingChildren(_ children: [BlockContent]) -> BlockQuoteNode {
+    return BlockQuoteNode(children: children, sourceRange: sourceRange)
+  }
+
+  /// Returns a new node equivalent to the receiver, but whose source range has been replaced with
+  /// the given value.
+  ///
+  /// - Parameter sourceRange: The new source range.
+  /// - Returns: The new node.
+  public func replacingSourceRange(_ sourceRange: Range<SourceLocation>?) -> BlockQuoteNode {
+    return BlockQuoteNode(children: children, sourceRange: sourceRange)
+  }
+}