minor performance improvement to parseLiteralValue

Author: RandomHashTags

Sources/HTMLKitParse/ParseLiteral.swift

@@ -54,9 +54,13 @@ extension HTMLKitUtilities {
                 string = "\\(" + member.singleLineDescription + ")"
             } else {
                 var expressionString = "\(expression)"
-                while expressionString.first?.isWhitespace ?? false {
-                    expressionString.removeFirst()
+                var removed = 0
+                var index = expressionString.startIndex
+                while index < expressionString.endIndex, expressionString[index].isWhitespace {
+                    removed += 1
+                    expressionString.formIndex(after: &index)
                 }
+                expressionString.removeFirst(removed)
                 while expressionString.last?.isWhitespace ?? false {
                     expressionString.removeLast()
                 }

Sources/HTMLKitUtilityMacros/HTMLElements.swift

@@ -63,7 +63,7 @@ enum HTMLElements: DeclarationMacro {
                             }
                         } else {
                             var isArray = false
-                            let (value_type, default_value, value_type_literal):(String, String, HTMLElementValueType) = parse_value_type(isArray: &isArray, key: key, label.expression)
+                            let (value_type, default_value, value_type_literal) = parse_value_type(isArray: &isArray, key: key, label.expression)
                             switch value_type_literal {
                             case .otherAttribute(let other):
                                 other_attributes.append((key, other))