libluna: Add String::trim

libluna/include/luna/String.h

@@ -32,6 +32,8 @@ class String
         return view().split_once(delim);
     }
 
+    void trim(StringView delim);
+
     static Result<String> format(const String& fmt, ...);
     static Result<String> format(StringView fmt, ...);
 

libluna/src/String.cpp

@@ -80,6 +80,25 @@ Result<Vector<String>> String::split(StringView delim) const
     return view().split(delim);
 }
 
+void String::trim(StringView delim)
+{
+    isize i = (isize)m_length;
+
+    while (i--)
+    {
+        char c = chars()[i];
+        if (!strchr(delim.chars(), c)) break;
+    }
+
+    i++;
+
+    if (m_inline) m_inline_storage[i] = '\0';
+    else
+        m_string[i] = '\0';
+
+    m_length = (usize)i;
+}
+
 const char& String::operator[](usize index) const
 {
     expect(index < m_length, "index out of range");