Remove backticks when creating Identifier

Added a new Identifier type which contains a name property

This name property contains a sanitized version of the TokenSyntax's
text property which for now only consists of trimming backticks

Author: adammcarter

Sources/SwiftSyntax/Identifier.swift

@@ -0,0 +1,28 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+/// An abstraction for sanitized values on a token.
+public struct Identifier {
+  /// The sanitized `text` of a token.
+  public let name: String
+
+  public init(_ token: TokenSyntax) {
+    let text = token.text
+
+    self.name =
+      if text.contains("`") {
+        String(text.trimmingCharacters(in: "`"))
+      } else {
+        text
+      }
+  }
+}

Sources/SwiftSyntax/Utils.swift

@@ -120,3 +120,29 @@ extension RawUnexpectedNodesSyntax {
     self.init(raw: raw)
   }
 }
+
+extension String {
+  func trimmingCharacters(in charactersToTrim: any BidirectionalCollection<Character>) -> Substring {
+    let leadingCharacters = countOfSequentialCharacters(charactersToTrim, in: self)
+    let trailingCharacters = countOfSequentialCharacters(charactersToTrim, in: reversed())
+
+    return dropFirst(leadingCharacters).dropLast(trailingCharacters)
+  }
+}
+
+private func countOfSequentialCharacters(
+  _ charactersToCount: any BidirectionalCollection<Character>,
+  in characters: any BidirectionalCollection<Character>
+) -> Int {
+  var count = 0
+
+  for character in characters {
+    if charactersToCount.contains(character) {
+      count += 1
+    } else {
+      break
+    }
+  }
+
+  return count
+}

Tests/SwiftSyntaxTest/IdentifierTests.swift

@@ -0,0 +1,27 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import SwiftSyntax
+import XCTest
+
+class IdentifierTests: XCTestCase {
+  public func testInit() {
+    let basicToken = TokenSyntax(stringLiteral: "sometoken")
+    XCTAssertEqual(Identifier(basicToken).name, "sometoken")
+
+    let backtickedToken = TokenSyntax(stringLiteral: "`backtickedtoken`")
+    XCTAssertEqual(Identifier(backtickedToken).name, "backtickedtoken")
+
+    let multiBacktickedToken = TokenSyntax(stringLiteral: "```backtickedtoken```")
+    XCTAssertEqual(Identifier(multiBacktickedToken).name, "backtickedtoken")
+  }
+}