Add doc comments

Author: StevenWong12

Sources/SwiftParser/IncrementalParseTransition.swift

@@ -43,6 +43,9 @@ public final class IncrementalParseReusedNodeCollector:
   }
 }
 
+/// Record the affect range for potential re-used nodes. When edits intersect the affect range, the node is not able to be re-used.
+///
+/// This is also a trigger to enable parser to parse incrementally.
 public final class IncrementalParseNodeAffectRangeCollector {
   fileprivate var nodeAffectRange: [RawSyntax.ID: Int] = [:]
 

Sources/SwiftParser/Lexer/LexemeSequence.swift

@@ -32,10 +32,12 @@ extension Lexer {
     /// usually less than 0.1% of the memory allocated by the syntax arena.
     var lexerStateAllocator = BumpPtrAllocator(slabSize: 256)
 
+    /// Compute the offset of the end of next token
     var offsetToNextTokenEnd: Int {
       self.getOffsetToStart(self.nextToken) + self.nextToken.byteLength
     }
 
+    /// See doc comments in ``LookaheadTracker``
     var lookaheadTracker: UnsafeMutablePointer<LookaheadTracker>
 
     fileprivate init(sourceBufferStart: Lexer.Cursor, cursor: Lexer.Cursor) {
@@ -61,10 +63,12 @@ extension Lexer {
       return self.nextToken
     }
 
+    /// Get the offset of `token` to `sourceBufferStart`.
     func getOffsetToStart(_ token: Lexer.Lexeme) -> Int {
       return self.sourceBufferStart.distance(to: token.cursor)
     }
 
+    /// Advance the the cursor by `offset` and reset `currentToken`
     mutating func advance(by offset: Int, currentToken: inout Lexer.Lexeme) {
       self.cursor = currentToken.cursor
       self.cursor.position = self.cursor.position.advanced(by: offset)

Sources/SwiftParser/Parser.swift

@@ -682,7 +682,7 @@ extension Parser {
   }
 }
 
-/// Record the furthest offset to `sourceBufferStart` that is reached by ``Parser.Lookahead`` or ``Parser.peek()`` in ``Lexer.LexemeSequence``
+/// Record the furthest offset to `sourceBufferStart` that is reached by  ``Parser.Peek()`` or ``Lookahead`` in ``Lexer/LexemeSequence``
 public struct LookaheadTracker {
   private var _furthestOffset: Int