AK: Add begin() and end() to String and StringView

Now it's possible to use range-based for loops with String and StringView.

3 files changed, 15 insertions, 6 deletions

diff --git a/AK/String.h b/AK/String.h
index c01c771219..a77799c0c1 100644
--- a/AK/String.h
+++ b/AK/String.h
@@ -57,6 +57,8 @@ namespace AK {
 
 class String {
 public:
+    using ConstIterator = const char*;
+
     ~String() {}
 
     String() {}
@@ -144,12 +146,14 @@ public:
     bool is_empty() const { return length() == 0; }
     size_t length() const { return m_impl ? m_impl->length() : 0; }
     const char* characters() const { return m_impl ? m_impl->characters() : nullptr; }
-    char operator[](size_t i) const
+    const char& operator[](size_t i) const
     {
-        ASSERT(m_impl);
         return (*m_impl)[i];
     }
 
+    ConstIterator begin() const { return characters(); }
+    ConstIterator end() const { return begin() + length(); }
+
     bool starts_with(const StringView&) const;
     bool ends_with(const StringView&) const;
     bool starts_with(char) const;
@@ -302,5 +306,5 @@ String escape_html_entities(const StringView& html);
 }
 
 using AK::CaseInsensitiveStringTraits;
-using AK::String;
 using AK::escape_html_entities;
+using AK::String;
diff --git a/AK/StringImpl.h b/AK/StringImpl.h
index 1e8d1082f6..1698d63984 100644
--- a/AK/StringImpl.h
+++ b/AK/StringImpl.h
@@ -26,8 +26,8 @@
 
 #pragma once
 
-#include <AK/RefPtr.h>
 #include <AK/RefCounted.h>
+#include <AK/RefPtr.h>
 #include <AK/Types.h>
 #include <AK/kmalloc.h>
 
@@ -57,7 +57,7 @@ public:
 
     size_t length() const { return m_length; }
     const char* characters() const { return &m_inline_buffer[0]; }
-    char operator[](size_t i) const
+    const char& operator[](size_t i) const
     {
         ASSERT(i < m_length);
         return characters()[i];
diff --git a/AK/StringView.h b/AK/StringView.h
index 41e7e7e652..a5c1bab2b0 100644
--- a/AK/StringView.h
+++ b/AK/StringView.h
@@ -34,6 +34,8 @@ namespace AK {
 
 class StringView {
 public:
+    using ConstIterator = const char*;
+
     StringView() {}
     StringView(const char* characters, size_t length)
         : m_characters(characters)
@@ -58,7 +60,10 @@ public:
     bool is_empty() const { return m_length == 0; }
     const char* characters_without_null_termination() const { return m_characters; }
     size_t length() const { return m_length; }
-    char operator[](size_t index) const { return m_characters[index]; }
+    const char& operator[](size_t index) const { return m_characters[index]; }
+
+    ConstIterator begin() const { return characters_without_null_termination(); }
+    ConstIterator end() const { return begin() + length(); }
 
     unsigned hash() const;