AK+LibWeb: Add a UTF-16 starts/ends with wrapper for a single code unit

Author: https://github.com/trflynn89
Commit: 1bc80848fb
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5746
Reviewed-by: https://github.com/gmta ✅

AK/Utf16StringBase.h

@@ -254,7 +254,10 @@ public:
 
     [[nodiscard]] ALWAYS_INLINE size_t count(Utf16View const& needle) const { return utf16_view().count(needle); }
 
+    [[nodiscard]] ALWAYS_INLINE bool starts_with(char16_t needle) const { return utf16_view().starts_with(needle); }
     [[nodiscard]] ALWAYS_INLINE bool starts_with(Utf16View const& needle) const { return utf16_view().starts_with(needle); }
+
+    [[nodiscard]] ALWAYS_INLINE bool ends_with(char16_t needle) const { return utf16_view().ends_with(needle); }
     [[nodiscard]] ALWAYS_INLINE bool ends_with(Utf16View const& needle) const { return utf16_view().ends_with(needle); }
 
     [[nodiscard]] ALWAYS_INLINE Vector<Utf16View> split_view(char16_t needle, SplitBehavior split_behavior) const { return utf16_view().split_view(needle, split_behavior); }

AK/Utf16View.h

@@ -579,6 +579,13 @@ public:
         return count;
     }
 
+    [[nodiscard]] constexpr bool starts_with(char16_t needle) const
+    {
+        if (is_empty())
+            return false;
+        return code_unit_at(0) == needle;
+    }
+
     [[nodiscard]] constexpr bool starts_with(Utf16View const& needle) const
     {
         auto needle_length = needle.length_in_code_units();
@@ -590,6 +597,13 @@ public:
         return substring_view(0, needle_length) == needle;
     }
 
+    [[nodiscard]] constexpr bool ends_with(char16_t needle) const
+    {
+        if (is_empty())
+            return false;
+        return code_unit_at(length_in_code_units() - 1) == needle;
+    }
+
     [[nodiscard]] constexpr bool ends_with(Utf16View const& needle) const
     {
         auto needle_length = needle.length_in_code_units();

Libraries/LibWeb/Editing/Commands.cpp

@@ -517,20 +517,20 @@ bool command_font_size_action(DOM::Document& document, Utf16String const& value)
     // 2. If value is not a valid floating point number, and would not be a valid floating point number if a single
     //    leading "+" character were stripped, return false.
     if (!HTML::is_valid_floating_point_number(resulting_value.to_utf8_but_should_be_ported_to_utf16())) {
-        if (!resulting_value.starts_with("+"sv)
+        if (!resulting_value.starts_with('+')
             || !HTML::is_valid_floating_point_number(resulting_value.substring_view(1).to_utf8_but_should_be_ported_to_utf16()))
             return false;
     }
 
     // 3. If the first character of value is "+", delete the character and let mode be "relative-plus".
     auto mode = FontSizeMode::Absolute;
-    if (resulting_value.starts_with("+"sv)) {
+    if (resulting_value.starts_with('+')) {
         resulting_value = resulting_value.substring_view(1);
         mode = FontSizeMode::RelativePlus;
     }
 
     // 4. Otherwise, if the first character of value is "-", delete the character and let mode be "relative-minus".
-    else if (resulting_value.starts_with("-"sv)) {
+    else if (resulting_value.starts_with('-')) {
         resulting_value = resulting_value.substring_view(1);
         mode = FontSizeMode::RelativeMinus;
     }
@@ -623,7 +623,7 @@ bool command_format_block_action(DOM::Document& document, Utf16String const& val
     // 1. If value begins with a "<" character and ends with a ">" character, remove the first and last characters from
     //    it.
     auto resulting_value = Utf16String::from_utf16_without_validation(
-        value.starts_with("<"sv) && value.ends_with(">"sv)
+        value.starts_with('<') && value.ends_with('>')
             ? value.substring_view(1, value.length_in_code_units() - 2)
             : value);
 

Libraries/LibWeb/Editing/Internal/Algorithms.cpp

@@ -498,7 +498,7 @@ void canonicalize_whitespace(DOM::BoundaryPoint boundary, bool fix_collapsed_spa
             // AD-HOC: Use the white-space-collapse longhand instead of "white-space" shorthand: https://github.com/w3c/editing/issues/486.
             if (is<DOM::Text>(*end_node) && end_offset == end_node->length() && precedes_a_line_break(end_node)) {
                 auto parent_white_space_collapse = resolved_keyword(*end_node->parent(), CSS::PropertyID::WhiteSpaceCollapse);
-                if (parent_white_space_collapse != CSS::Keyword::Preserve && end_node->text_content()->ends_with(" "sv)) {
+                if (parent_white_space_collapse != CSS::Keyword::Preserve && end_node->text_content()->ends_with(' ')) {
                     // 1. Subtract one from end offset.
                     --end_offset;
 

Libraries/LibWeb/HTML/Dates.cpp

@@ -55,7 +55,7 @@ bool is_valid_week_string(Utf16View const& value)
         if (!is_ascii_digit(digit))
             return false;
 
-    if (!parts[1].starts_with("W"sv))
+    if (!parts[1].starts_with('W'))
         return false;
     if (!is_ascii_digit(parts[1].code_unit_at(1)))
         return false;

Libraries/LibWeb/HTML/HTMLInputElement.cpp

@@ -1615,7 +1615,7 @@ static bool is_valid_simple_color(Utf16View const& value)
     if (value.length_in_code_units() != 7)
         return false;
     // and the first character is a U+0023 NUMBER SIGN character (#),
-    if (!value.starts_with("#"sv))
+    if (!value.starts_with('#'))
         return false;
     // and the remaining six characters are all ASCII hex digits
     for (size_t i = 1; i < value.length_in_code_units(); i++)

Libraries/LibWeb/HTML/Scripting/ImportMap.cpp

@@ -163,7 +163,7 @@ WebIDL::ExceptionOr<ModuleSpecifierMap> sort_and_normalise_module_specifier_map(
         }
 
         // 6. If specifierKey ends with U+002F (/), and the serialization of addressURL does not end with U+002F (/), then:
-        if (specifier_key.as_string().view().ends_with("/"sv) && !address_url->serialize().ends_with('/')) {
+        if (specifier_key.as_string().view().ends_with('/') && !address_url->serialize().ends_with('/')) {
             // 1. The user agent may report a warning to the console indicating that an invalid address was given for the specifier key specifierKey; since specifierKey ends with a slash, the address needs to as well.
             auto& console = realm.intrinsics().console_object()->console();
             console.output_debug_message(JS::Console::LogLevel::Warn,

Libraries/LibWeb/Infra/Strings.cpp

@@ -96,7 +96,7 @@ Utf16String strip_and_collapse_whitespace(Utf16String const& string)
 
     for (auto code_point : string) {
         if (Infra::is_ascii_whitespace(code_point)) {
-            if (!builder.utf16_string_view().ends_with(" "sv))
+            if (!builder.utf16_string_view().ends_with(' '))
                 builder.append(' ');
             continue;
         }