Added string.starts string.ends functions

tests/utils.lua

@@ -49,6 +49,26 @@ TestUtils = {} --class
     function TestUtils:test_explode()
         assertItemsEquals(explode(',',"1,2,3"), {'1','2','3'})
     end
+
+    function TestUtils:test_starts()
+        assertError(string.stats, nil, "g")
+        assertTrue(string.starts("goga", "g"))
+        assertTrue(string.starts("goga", "go"))
+        assertTrue(string.starts("goga", "gog"))
+        assertTrue(string.starts("goga", "goga"))
+        assertFalse(string.starts("goga", "a"))
+        assertError(string.starts, "goga", nil)
+    end
+
+    function TestUtils:test_ends()
+        assertError(string.ends, nil, "g")
+        assertTrue(string.ends("goga", "a"))
+        assertTrue(string.ends("goga", "ga"))
+        assertTrue(string.ends("goga", "oga"))
+        assertTrue(string.ends("goga", "goga"))
+        assertFalse(string.ends("goga", "f"))
+        assertError(string.ends, "goga", nil)
+    end
 -- class TestUtils
 
 TestStack = {}

utils.lua

@@ -120,6 +120,14 @@ function explode(delimiter, text)
     return list
 end
 
+function string.starts(String,Start)
+   return string.sub(String,1,string.len(Start))==Start
+end
+
+function string.ends(String,End)
+   return End=='' or string.sub(String,-string.len(End))==End
+end
+
 -- Stack Table
 -- Uses a table as stack, use <table>:push(value) and <table>:pop()
 -- Lua 5.1 compatible