core: added StartsWith and EndsWith function for strings, and a sign function for numeric types

src/lol/base/string.h

@@ -158,6 +158,42 @@ public:
         return -1;
     }
 
+    bool StartsWith(char const* token) const
+    {
+        const char* p = C();
+        while (*token != '\0')
+        {
+            if (*p != *token)
+                return false;
+
+            ++p;
+            ++token;
+        }
+
+        return true;
+    }
+
+    bool EndsWith(char const* token) const
+    {
+        const char* p = C();
+        int token_idx = strlen(token) - 1;
+        int c_idx = strlen(p) - 1;
+
+        if (c_idx < token_idx)
+            return false;
+
+        while (token_idx >= 0)
+        {
+            if (token[token_idx] != p[c_idx])
+                return false;
+
+            --token_idx;
+            --c_idx;
+        }
+
+        return true;
+    }
+
     inline String operator +(String const &s) const
     {
         String ret(*this);

src/lol/math/functions.h

@@ -171,7 +171,9 @@ static inline ldouble ceil(ldouble x) { return std::ceil(x); }
     static inline T fract(T x) { return x - lol::floor(x); } \
     static inline T min(T x, T y) { return std::min(x, y); } \
     static inline T max(T x, T y) { return std::max(x, y); } \
-    static inline T clamp(T x, T y, T z) { return min(max(x, y), z); }
+    static inline T clamp(T x, T y, T z) { return min(max(x, y), z); } \
+    static inline T sign(T x) { return (T)(((T)0 < x) - (x < (T)0)); }
+
 LOL_GENERIC_FUNC(uint8_t)
 LOL_GENERIC_FUNC(int8_t)
 LOL_GENERIC_FUNC(uint16_t)

test/unit/string.cpp

@@ -218,7 +218,19 @@ LOLUNIT_FIXTURE(StringTest)
         LOLUNIT_ASSERT(i7 == 0);
         LOLUNIT_ASSERT(i8 == -1);
         LOLUNIT_ASSERT(i9 == 9);
-    }};
+    }
+
+    LOLUNIT_TEST(StartsEndsWith)
+    {
+        String s = "lolilol";
+        LOLUNIT_ASSERT(s.StartsWith("loli"));
+        LOLUNIT_ASSERT(!s.StartsWith("lolo"));
+        LOLUNIT_ASSERT(!s.StartsWith("lolilolilol"));
+        LOLUNIT_ASSERT(s.EndsWith("ilol"));
+        LOLUNIT_ASSERT(!s.EndsWith("olol"));
+        LOLUNIT_ASSERT(!s.EndsWith("lolilolilol"));
+    }
+};
 
 } /* namespace lol */