Improve documentation.

Author: MAJKFL

Sources/SwiftLexicalLookup/Configurations/FileScopeNameIntroductionStrategy.swift

@@ -14,12 +14,12 @@ import SwiftSyntax
 
 /// Specifies how names should be introduced at the file scope.
 @_spi(Experimental) public enum FileScopeHandlingConfig {
-  /// Default behavior. Names introduced sequentially like in member block
-  /// scope up to the first non-declaration after and including which,
-  /// the declarations are treated like in code block scope.
+  /// This is the behavior that is being used 
+  /// for Swift files with top-level code.
   case memberBlockUpToLastDecl
-  /// File scope behaves like member block scope.
+  /// This is the behavior that is being used 
+  /// for Swift files that don’t allow top-level code.
   case memberBlock
-  /// File scope behaves like code block scope.
+  /// This is the behavior that is being used for e.g. function bodies.
   case codeBlock
 }

Sources/SwiftLexicalLookup/Configurations/LookupConfig.swift

@@ -13,10 +13,13 @@
 import Foundation
 
 @_spi(Experimental) public struct LookupConfig {
-  /// Specifies behaviour of file scope.
-  /// `memberBlockUpToLastDecl` by default.
+  /// Specifies behavior of file scope.
   @_spi(Experimental) public var fileScopeHandling: FileScopeHandlingConfig
 
+  /// Creates a new lookup configuration.
+  ///
+  /// - `fileScopeHandling` - specifies behavior of file scope.
+  ///   `memberBlockUpToLastDecl` by default.
   @_spi(Experimental) public init(
     fileScopeHandling: FileScopeHandlingConfig = .memberBlockUpToLastDecl
   ) {

Sources/SwiftLexicalLookup/LookupName.swift

@@ -125,6 +125,13 @@ import SwiftSyntax
   }
 
   /// Extracts names introduced by the given `syntax` structure.
+  ///
+  /// When e.g. looking up a variable declaration like `let a = a`,
+  /// we expect `a` to be visible after the whole declaration.
+  /// That's why we can't just use `syntax.endPosition` for the `a` identifier pattern,
+  /// as the name would already be visible at the `a` reference withing the declaration.
+  /// That’s why code block and file scopes have to set
+  /// `accessibleAfter` to be the end position of the entire declaration syntax node.
   static func getNames(
     from syntax: SyntaxProtocol,
     accessibleAfter: AbsolutePosition? = nil

Sources/SwiftLexicalLookup/ScopeImplementations.swift

@@ -81,7 +81,7 @@ import SwiftSyntax
   }
 
   /// Returns names matching lookup using provided file
-  /// scope handling configuration (by default: `memberBlockUpToLastDecl`).
+  /// scope handling configuration.
   ///
   /// Example usage:
   /// ```swift