From 26bc3d4ea02cce2cf7f11b66d1fe978c3de89f76 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sun, 22 Mar 2020 13:07:45 +0100
Subject: [PATCH] AK: Add FlyString::equals_ignoring_case(StringView)

And share the code with String by moving the logic to StringUtils. :^)
---
 AK/FlyString.cpp   |  5 +++++
 AK/FlyString.h     |  2 ++
 AK/String.cpp      | 17 +----------------
 AK/StringUtils.cpp | 20 ++++++++++++++++++++
 AK/StringUtils.h   |  1 +
 AK/StringView.h    |  2 ++
 6 files changed, 31 insertions(+), 16 deletions(-)

diff --git a/AK/FlyString.cpp b/AK/FlyString.cpp
index 772f100710..dc199ba778 100644
--- a/AK/FlyString.cpp
+++ b/AK/FlyString.cpp
@@ -88,4 +88,9 @@ int FlyString::to_int(bool& ok) const
     return StringUtils::convert_to_int(view(), ok);
 }
 
+bool FlyString::equals_ignoring_case(const StringView& other) const
+{
+    return StringUtils::equals_ignoring_case(view(), other);
+}
+
 }
diff --git a/AK/FlyString.h b/AK/FlyString.h
index c9290a8313..9876cbf031 100644
--- a/AK/FlyString.h
+++ b/AK/FlyString.h
@@ -48,6 +48,8 @@ public:
 
     int to_int(bool& ok) const;
 
+    bool equals_ignoring_case(const StringView&) const;
+
     static void did_destroy_impl(Badge<StringImpl>, StringImpl&);
 
 private:
diff --git a/AK/String.cpp b/AK/String.cpp
index 81e6e517a1..ec74a38742 100644
--- a/AK/String.cpp
+++ b/AK/String.cpp
@@ -38,13 +38,6 @@
 extern "C" char* strstr(const char* haystack, const char* needle);
 #endif
 
-static inline char to_lowercase(char c)
-{
-    if (c >= 'A' && c <= 'Z')
-        return c | 0x20;
-    return c;
-}
-
 namespace AK {
 
 bool String::operator==(const String& other) const
@@ -309,15 +302,7 @@ bool String::contains(const String& needle) const
 
 bool String::equals_ignoring_case(const StringView& other) const
 {
-    if (other.m_impl == impl())
-        return true;
-    if (length() != other.length())
-        return false;
-    for (size_t i = 0; i < length(); ++i) {
-        if (::to_lowercase(characters()[i]) != ::to_lowercase(other.characters_without_null_termination()[i]))
-            return false;
-    }
-    return true;
+    return StringUtils::equals_ignoring_case(view(), other);
 }
 
 String escape_html_entities(const StringView& html)
diff --git a/AK/StringUtils.cpp b/AK/StringUtils.cpp
index 3c96a03384..7f6c6f4a97 100644
--- a/AK/StringUtils.cpp
+++ b/AK/StringUtils.cpp
@@ -143,6 +143,26 @@ unsigned convert_to_uint(const StringView& str, bool& ok)
     return value;
 }
 
+static inline char to_lowercase(char c)
+{
+    if (c >= 'A' && c <= 'Z')
+        return c | 0x20;
+    return c;
+}
+
+bool equals_ignoring_case(const StringView& a, const StringView& b)
+{
+    if (a.impl() && a.impl() == b.impl())
+        return true;
+    if (a.length() != b.length())
+        return false;
+    for (size_t i = 0; i < a.length(); ++i) {
+        if (to_lowercase(a.characters_without_null_termination()[i]) != to_lowercase(b.characters_without_null_termination()[i]))
+            return false;
+    }
+    return true;
+}
+
 }
 
 }
diff --git a/AK/StringUtils.h b/AK/StringUtils.h
index 5f19888d48..f4b433b8ef 100644
--- a/AK/StringUtils.h
+++ b/AK/StringUtils.h
@@ -41,6 +41,7 @@ namespace StringUtils {
 bool matches(const StringView& str, const StringView& mask, CaseSensitivity = CaseSensitivity::CaseInsensitive);
 int convert_to_int(const StringView&, bool& ok);
 unsigned convert_to_uint(const StringView&, bool& ok);
+bool equals_ignoring_case(const StringView&, const StringView&);
 
 }
 
diff --git a/AK/StringView.h b/AK/StringView.h
index 00e1af1e69..068873400a 100644
--- a/AK/StringView.h
+++ b/AK/StringView.h
@@ -139,6 +139,8 @@ public:
         return !(*this == other);
     }
 
+    const StringImpl* impl() const { return m_impl; }
+
 private:
     friend class String;
     const StringImpl* m_impl { nullptr };