base: new string functions.

Add String.split(char) to split into an array, and add a simple
char const * + lol::String free operator.

src/lol/base/string.h

@@ -228,6 +228,24 @@ public:
                 && memcmp(C() + count() - s.count(), s.C(), s.count()) == 0;
     }
 
+    array<String> split(char c = '\n') const
+    {
+        array<String> ret;
+        for (int start = 0; start < m_count; )
+        {
+            char const *tmp = strchr(C() + start, c);
+            if (!tmp)
+            {
+                ret.push(String(C() + start));
+                break;
+            }
+            int size = tmp - C() - start;
+            ret.push(String(C() + start, size));
+            start += size + 1;
+        }
+        return ret;
+    }
+
     bool is_alpha() const
     {
         for (int i = 0; i < m_count; i++)
@@ -312,6 +330,11 @@ public:
     static String vformat(char const *format, va_list ap);
 };
 
+inline String operator +(char const *sz, String const &s)
+{
+    return String(sz) + s;
+}
+
 inline bool operator ==(char const* sz, String const &s)
 {
     return s == sz;

src/t/base/string.cpp

@@ -240,6 +240,37 @@ lolunit_declare_fixture(string_test)
         lolunit_assert(s1 < s4);
         lolunit_assert(!(s4 < s1));
     }
+
+    lolunit_declare_test(string_split)
+    {
+        auto l1 = String("abc").split();
+        lolunit_assert(l1.count() == 1);
+        lolunit_assert(l1[0] == "abc");
+
+        auto l2 = String("\nabc").split();
+        lolunit_assert(l2.count() == 2);
+        lolunit_assert(l2[0] == "");
+        lolunit_assert(l2[1] == "abc");
+
+        auto l3 = String("abc\n").split();
+        lolunit_assert(l3.count() == 2);
+        lolunit_assert(l3[0] == "abc");
+        lolunit_assert(l3[1] == "");
+
+        auto l4 = String("\n\n").split();
+        lolunit_assert(l4.count() == 3);
+        lolunit_assert(l4[0] == "");
+        lolunit_assert(l4[1] == "");
+        lolunit_assert(l4[2] == "");
+
+        auto l5 = String("abc\nde\n\nf\n").split();
+        lolunit_assert(l5.count() == 5);
+        lolunit_assert(l5[0] == "abc");
+        lolunit_assert(l5[1] == "de");
+        lolunit_assert(l5[2] == "");
+        lolunit_assert(l5[3] == "f");
+        lolunit_assert(l5[4] == "");
+    }
 };
 
 } /* namespace lol */