Added TokenSyntax identifier property

This acts as a convenience property to convert a TokenSyntax to an
Identifier

Author: adammcarter

Sources/SwiftSyntax/Identifier.swift

@@ -11,7 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 /// An abstraction for sanitized values on a token.
-public struct Identifier {
+public struct Identifier: Equatable {
   /// The sanitized `text` of a token.
   public let name: String
 

Sources/SwiftSyntax/TokenSyntax.swift

@@ -153,6 +153,11 @@ public struct TokenSyntax: SyntaxProtocol, SyntaxHashable {
     }
   }
 
+  /// An identifier created from `self`.
+  public var identifier: Identifier {
+    Identifier(self)
+  }
+
   /// A token by itself has no structure, so we represent its structure by an
   /// empty layout node.
   ///

Tests/SwiftSyntaxTest/IdentifierTests.swift

@@ -24,4 +24,9 @@ class IdentifierTests: XCTestCase {
     let multiBacktickedToken = TokenSyntax(stringLiteral: "```backtickedtoken```")
     XCTAssertEqual(Identifier(multiBacktickedToken).name, "backtickedtoken")
   }
+
+  public func testTokenSyntaxIdentifier() {
+    let tokenSyntax = TokenSyntax(stringLiteral: "sometoken")
+    XCTAssertEqual(tokenSyntax.identifier, Identifier(tokenSyntax))
+  }
 }