draft implementation for eagarly inlining snippets

Author: tayloraswift

Package.resolved

@@ -99,7 +99,7 @@ let package:Package = .init(
         .package(url: "https://github.com/tayloraswift/swift-hash", .upToNextMinor(
             from: "0.5.0")),
         .package(url: "https://github.com/tayloraswift/swift-mongodb", .upToNextMinor(
-            from: "0.12.0")),
+            from: "0.12.1")),
         //.package(path: "../swift-mongodb"),
 
         .package(url: "https://github.com/tayloraswift/swift-png", .upToNextMinor(
@@ -108,14 +108,17 @@ let package:Package = .init(
         .package(url: "https://github.com/apple/swift-atomics", .upToNextMinor(
             from: "1.2.0")),
 
+        .package(url: "https://github.com/apple/swift-collections.git", .upToNextMinor(
+            from: "1.1.0")),
+
         /// swift-nio has a low rate of breakage, and can be trusted with a major-only
         /// version requirement.
         .package(url: "https://github.com/apple/swift-nio",
-            from: "2.62.0"),
+            from: "2.63.0"),
         /// swift-nio-ssl has a low rate of breakage, and can be trusted with a
         /// major-only version requirement.
         .package(url: "https://github.com/apple/swift-nio-ssl",
-            from: "2.25.0"),
+            from: "2.26.0"),
 
         .package(url: "https://github.com/apple/swift-nio-http2", .upToNextMinor(
             from: "1.29.0")),
@@ -127,7 +130,7 @@ let package:Package = .init(
         .package(url: "https://github.com/apple/swift-system", .upToNextMinor(
             from: "1.2.1")),
         .package(url: "https://github.com/apple/swift-syntax",
-            exact: "509.0.2"),
+            exact: "509.1.1"),
     ],
     targets:
     [
@@ -332,7 +335,10 @@ let package:Package = .init(
                 .target(name: "Codelinks"),
                 .target(name: "MarkdownAST"),
                 .target(name: "Sources"),
+                .target(name: "Snippets"),
                 .target(name: "UnidocDiagnostics"),
+
+                .product(name: "OrderedCollections", package: "swift-collections"),
             ]),
 
         .target(name: "MD5", dependencies:

Package.swift

@@ -30,6 +30,12 @@ extension Markdown.BinaryEncoder
 }
 extension Markdown.BinaryEncoder
 {
+    @inlinable public static
+    func += (self:inout Self, bytecode:Markdown.Bytecode)
+    {
+        self.bytecode.bytes += bytecode.bytes
+    }
+
     @inlinable public static
     func += (self:inout Self, codepoint:Unicode.Scalar)
     {

Sources/MarkdownABI/Bytecode/Markdown.BinaryEncoder.swift

@@ -26,14 +26,15 @@ extension Markdown.SwiftLanguage:Markdown.CodeLanguageType
 extension Markdown.SwiftLanguage
 {
     public
-    func parse(snippet utf8:[UInt8]) -> (overview:String, slices:[Snippet.Slice])
+    func parse(snippet utf8:[UInt8]) -> (overview:String, slices:[Markdown.SnippetSlice])
     {
         //  It is safe to escape the pointer to ``Parser.parse(source:maximumNestingLevel:)``,
         //  see: https://swiftinit.org/docs/swift-syntax/swiftparser/parser.init(_:maximumnestinglevel:parsetransition:arena:)
         let parsed:SourceFileSyntax = utf8.withUnsafeBufferPointer
         {
             Parser.parse(source: $0)
         }
+
         var start:AbsolutePosition = parsed.position
         var text:String = ""
         lines:
@@ -78,7 +79,8 @@ extension Markdown.SwiftLanguage
             text.append("\n")
         }
 
-        var parser:SnippetParser = .init(start: start)
+        var parser:SnippetParser = .init(sourcemap: .init(fileName: "", tree: parsed),
+            start: start)
         for token:TokenSyntax in parsed.tokens(viewMode: .sourceAccurate)
         {
             parser.visit(token: token)
@@ -89,7 +91,7 @@ extension Markdown.SwiftLanguage
         var spans:SyntaxClassifications.Iterator = parsed.classifications.makeIterator()
         var span:SyntaxClassifiedRange? = spans.next()
 
-        let rendered:[Snippet.Slice] = slices.map
+        let rendered:[Markdown.SnippetSlice] = slices.map
         {
             (slice:SnippetParser.Slice) in
 
@@ -133,7 +135,7 @@ extension Markdown.SwiftLanguage
                 }
             }
 
-            return .init(id: slice.id, bytecode: bytecode)
+            return .init(id: slice.id, line: slice.line, code: bytecode)
         }
 
         return (text, rendered)

Sources/MarkdownPluginSwift/Markdown.SwiftLanguage.swift

@@ -8,11 +8,13 @@ extension SnippetParser
     struct Slice
     {
         let id:String
+        let line:Int
         var ranges:[Range<Int>]
 
-        init(id:String, ranges:[Range<Int>])
+        init(id:String, line:Int, ranges:[Range<Int>])
         {
             self.id = id
+            self.line = line
             self.ranges = ranges
         }
     }

Sources/MarkdownPluginSwift/Snippets/SnippetParser.Slice.swift

@@ -7,13 +7,13 @@ extension SnippetParser
     struct SliceBounds
     {
         let id:String
-        var indent:Int
+        var marker:(line:Int, indent:Int)
         var ranges:[Range<AbsolutePosition>]
 
-        init(id:String, indent:Int)
+        init(id:String, marker:(line:Int, indent:Int))
         {
             self.id = id
-            self.indent = indent
+            self.marker = marker
             self.ranges = []
         }
     }
@@ -47,7 +47,7 @@ extension SnippetParser.SliceBounds
         }
 
         //  Compute maximum removable indentation.
-        var indent:Int = self.indent
+        var indent:Int = self.marker.indent
         for range:Range<Int> in ranges
         {
             /// We initialize this to 0 and not nil because we assume the range starts at the
@@ -83,12 +83,12 @@ extension SnippetParser.SliceBounds
         }
 
 
-        if  self.indent == 0
+        if  self.marker.indent == 0
         {
-            return .init(id: self.id, ranges: ranges)
+            return .init(id: self.id, line: self.marker.line, ranges: ranges)
         }
 
-        var slice:SnippetParser.Slice = .init(id: self.id, ranges: [])
+        var slice:SnippetParser.Slice = .init(id: self.id, line: self.marker.line, ranges: [])
             slice.ranges.reserveCapacity(ranges.count)
 
         for range:Range<Int> in ranges
@@ -112,7 +112,7 @@ extension SnippetParser.SliceBounds
                     continue
 
                 case    (_, let i?):
-                    slice.punch(hole: (i ..< j).prefix(self.indent))
+                    slice.punch(hole: (i ..< j).prefix(self.marker.indent))
                     start = nil
 
                 case    (_, nil):

Sources/MarkdownPluginSwift/Snippets/SnippetParser.SliceBounds.swift

@@ -10,9 +10,9 @@ extension SnippetParser
         private
         var start:AbsolutePosition?
 
-        init(id:String, at position:AbsolutePosition, indent:Int = 0)
+        init(id:String, position:AbsolutePosition, marker:(line:Int, indent:Int) = (1, 0))
         {
-            self.slice = .init(id: id, indent: indent)
+            self.slice = .init(id: id, marker: marker)
             self.start = position
         }
     }

Sources/MarkdownPluginSwift/Snippets/SnippetParser.SliceFetus.swift

@@ -5,12 +5,14 @@ extension SnippetParser
     struct SliceMarker
     {
         let statement:Statement
-        /// The number of leading spaces before the control comment.
+        /// The number of leading spaces before the slice marker.
         let indent:Int
-        /// The UTF-8 offset of the (first) newline before the control comment, or the beginning
+        /// The UTF-8 offset of the (first) newline before the slice marker, or the beginning
         /// of the file if the control comment is at the beginning of the file.
         let before:AbsolutePosition
-        /// The UTF-8 offset of the newline after the control comment, assuming it exists.
+        /// The UTF-8 offset of the newline after the slice marker, assuming it exists.
         let after:AbsolutePosition
+        /// The line number (1-indexed) of the slice marker.
+        let line:Int
     }
 }

Sources/MarkdownPluginSwift/Snippets/SnippetParser.SliceMarker.swift

@@ -2,13 +2,18 @@ import SwiftSyntax
 
 struct SnippetParser
 {
+    private
+    let sourcemap:SourceLocationConverter
+
     var complete:[SliceBounds]
     var current:SliceFetus?
 
-    init(start position:AbsolutePosition)
+    init(sourcemap:SourceLocationConverter, start position:AbsolutePosition)
     {
+        self.sourcemap = sourcemap
+
         self.complete = []
-        self.current = .init(id: "", at: position)
+        self.current = .init(id: "", position: position)
     }
 }
 extension SnippetParser
@@ -74,6 +79,7 @@ extension SnippetParser
 
             if  let statement:SliceMarker.Statement = .init(lineComment: line, skip: skip)
             {
+                let location:SourceLocation = self.sourcemap.location(for: current)
                 //  We know that line comments always extend to the end of the line.
                 //  Therefore, `range.upperBound` “always” points to a newline, and the start of
                 //  the next line is one after the index after the end of the comment.
@@ -84,7 +90,8 @@ extension SnippetParser
                 self.push(marker: .init(statement: statement,
                     indent: leading.indent,
                     before: leading.position,
-                    after: range.upperBound.advanced(by: 1)))
+                    after: range.upperBound.advanced(by: 1),
+                    line: location.line))
             }
             else
             {
@@ -138,7 +145,9 @@ extension SnippetParser
                 self.complete.append(slice)
             }
 
-            self.current = .init(id: id, at: marker.after, indent: marker.indent)
+            self.current = .init(id: id,
+                position: marker.after,
+                marker: (line: marker.line, indent: marker.indent))
         }
     }
 }

Sources/MarkdownPluginSwift/Snippets/SnippetParser.swift

@@ -0,0 +1 @@
+@_exported import enum MarkdownABI.Markdown