AK: Move trim_whitespace() into StringUtils and add it to StringView

No behaviour change; also patches use of `String::TrimMode` in LibJS.

AK/String.cpp

@@ -337,44 +337,6 @@ int String::replace(const String& needle, const String& replacement, bool all_oc
     return positions.size();
 }
 
-String String::trim_whitespace(TrimMode mode) const
-{
-    auto is_whitespace_character = [](char ch) -> bool {
-        return ch == '\t'
-            || ch == '\n'
-            || ch == '\v'
-            || ch == '\f'
-            || ch == '\r'
-            || ch == ' ';
-    };
-
-    size_t substring_start = 0;
-    size_t substring_length = length();
-
-    if (mode == TrimMode::Left || mode == TrimMode::Both) {
-        for (size_t i = 0; i < length(); ++i) {
-            if (substring_length == 0)
-                return "";
-            if (!is_whitespace_character(characters()[i]))
-                break;
-            ++substring_start;
-            --substring_length;
-        }
-    }
-
-    if (mode == TrimMode::Right || mode == TrimMode::Both) {
-        for (size_t i = length() - 1; i > 0; --i) {
-            if (substring_length == 0)
-                return "";
-            if (!is_whitespace_character(characters()[i]))
-                break;
-            --substring_length;
-        }
-    }
-
-    return substring(substring_start, substring_length);
-}
-
 String escape_html_entities(const StringView& html)
 {
     StringBuilder builder;

AK/String.h

@@ -119,12 +119,12 @@ public:
     String to_lowercase() const;
     String to_uppercase() const;
 
-    enum class TrimMode {
-        Left,
-        Right,
-        Both
-    };
-    String trim_whitespace(TrimMode mode = TrimMode::Both) const;
+#ifndef KERNEL
+    String trim_whitespace(TrimMode mode = TrimMode::Both) const
+    {
+        return StringUtils::trim_whitespace(StringView { characters(), length() }, mode);
+    }
+#endif
 
     bool equals_ignoring_case(const StringView&) const;
 

AK/StringUtils.cpp

@@ -227,6 +227,43 @@ bool starts_with(const StringView& str, const StringView& start, CaseSensitivity
     return true;
 }
 
+StringView trim_whitespace(const StringView& str, TrimMode mode)
+{
+    auto is_whitespace_character = [](char ch) -> bool {
+        return ch == '\t'
+            || ch == '\n'
+            || ch == '\v'
+            || ch == '\f'
+            || ch == '\r'
+            || ch == ' ';
+    };
+
+    size_t substring_start = 0;
+    size_t substring_length = str.length();
+
+    if (mode == TrimMode::Left || mode == TrimMode::Both) {
+        for (size_t i = 0; i < str.length(); ++i) {
+            if (substring_length == 0)
+                return "";
+            if (!is_whitespace_character(str[i]))
+                break;
+            ++substring_start;
+            --substring_length;
+        }
+    }
+
+    if (mode == TrimMode::Right || mode == TrimMode::Both) {
+        for (size_t i = str.length() - 1; i > 0; --i) {
+            if (substring_length == 0)
+                return "";
+            if (!is_whitespace_character(str[i]))
+                break;
+            --substring_length;
+        }
+    }
+
+    return str.substring_view(substring_start, substring_length);
+}
 }
 
 }

AK/StringUtils.h

@@ -36,6 +36,12 @@ enum class CaseSensitivity {
     CaseSensitive,
 };
 
+enum class TrimMode {
+    Left,
+    Right,
+    Both
+};
+
 namespace StringUtils {
 
 bool matches(const StringView& str, const StringView& mask, CaseSensitivity = CaseSensitivity::CaseInsensitive);
@@ -45,8 +51,10 @@ Optional<unsigned> convert_to_uint_from_hex(const StringView&);
 bool equals_ignoring_case(const StringView&, const StringView&);
 bool ends_with(const StringView& a, const StringView& b, CaseSensitivity);
 bool starts_with(const StringView&, const StringView&, CaseSensitivity);
+StringView trim_whitespace(const StringView&, TrimMode mode);
 }
 
 }
 
 using AK::CaseSensitivity;
+using AK::TrimMode;

AK/StringView.h

@@ -91,6 +91,8 @@ public:
     bool contains(const StringView&) const;
     bool equals_ignoring_case(const StringView& other) const;
 
+    StringView trim_whitespace(TrimMode mode = TrimMode::Both) const { return StringUtils::trim_whitespace(*this, mode); }
+
     Optional<size_t> find_first_of(char) const;
     Optional<size_t> find_first_of(const StringView&) const;
 

Libraries/LibJS/Runtime/StringPrototype.cpp

@@ -282,7 +282,7 @@ JS_DEFINE_NATIVE_FUNCTION(StringPrototype::trim)
     auto string = ak_string_from(vm, global_object);
     if (string.is_null())
         return {};
-    return js_string(vm, string.trim_whitespace(String::TrimMode::Both));
+    return js_string(vm, string.trim_whitespace(TrimMode::Both));
 }
 
 JS_DEFINE_NATIVE_FUNCTION(StringPrototype::trim_start)
@@ -290,7 +290,7 @@ JS_DEFINE_NATIVE_FUNCTION(StringPrototype::trim_start)
     auto string = ak_string_from(vm, global_object);
     if (string.is_null())
         return {};
-    return js_string(vm, string.trim_whitespace(String::TrimMode::Left));
+    return js_string(vm, string.trim_whitespace(TrimMode::Left));
 }
 
 JS_DEFINE_NATIVE_FUNCTION(StringPrototype::trim_end)
@@ -298,7 +298,7 @@ JS_DEFINE_NATIVE_FUNCTION(StringPrototype::trim_end)
     auto string = ak_string_from(vm, global_object);
     if (string.is_null())
         return {};
-    return js_string(vm, string.trim_whitespace(String::TrimMode::Right));
+    return js_string(vm, string.trim_whitespace(TrimMode::Right));
 }
 
 JS_DEFINE_NATIVE_FUNCTION(StringPrototype::concat)