Added underscore to selection

Sources/CodeEditTextView/Extensions/CharacterSet.swift

@@ -0,0 +1,14 @@
+//
+//  CharacterSet.swift
+//  CodeEditTextView
+//
+//  Created by Abe Malla on 3/29/25.
+//
+
+import Foundation
+
+extension CharacterSet {
+    /// Returns a character set containing the characters common in code names
+    static let codeIdentifierCharacters: CharacterSet = .alphanumerics
+        .union(.init(charactersIn: "_"))
+}

Sources/CodeEditTextView/TextSelectionManager/SelectionManipulation/SelectionManipulation+Horizontal.swift

@@ -109,10 +109,11 @@ package extension TextSelectionManager {
 
             if hasFoundValidWordChar && CharacterSet.punctuationCharacters
                 .union(.whitespacesAndNewlines)
+                .subtracting(CharacterSet.codeIdentifierCharacters)
                 .isSuperset(of: CharacterSet(charactersIn: substring)) {
                 stop.pointee = true
                 return
-            } else if CharacterSet.alphanumerics.isSuperset(of: CharacterSet(charactersIn: substring)) {
+            } else if CharacterSet.codeIdentifierCharacters.isSuperset(of: CharacterSet(charactersIn: substring)) {
                 hasFoundValidWordChar = true
             }
             rangeToDelete.length += substring.count

Sources/CodeEditTextView/TextView/TextView+Select.swift

@@ -37,8 +37,8 @@ extension TextView {
             }
             let charSet = CharacterSet(charactersIn: String(char))
             let characterSet: CharacterSet
-            if CharacterSet.alphanumerics.isSuperset(of: charSet) {
-                characterSet = .alphanumerics
+            if CharacterSet.codeIdentifierCharacters.isSuperset(of: charSet) {
+                characterSet = .codeIdentifierCharacters
             } else if CharacterSet.whitespaces.isSuperset(of: charSet) {
                 characterSet = .whitespaces
             } else if CharacterSet.newlines.isSuperset(of: charSet) {