Define startsWith and endsWith in PS

Author: triallax

src/Data/String/CodeUnits.js

@@ -116,15 +116,3 @@ exports.splitAt = function (i) {
     return { before: s.substring(0, i), after: s.substring(i) };
   };
 };
-
-exports.startsWith = function (pattern) {
-  return function (s) {
-    return s.startsWith(pattern);
-  };
-};
-
-exports.endsWith = function (pattern) {
-  return function (s) {
-    return s.endsWith(pattern);
-  };
-};

src/Data/String/CodeUnits.purs

@@ -352,12 +352,14 @@ foreign import splitAt :: Int -> String -> { before :: String, after :: String }
 -- | startsWith (Pattern "foo") "foobar" == true
 -- | startsWith (Pattern "bar") "foobar" == false
 -- | ```
-foreign import startsWith :: Pattern -> String -> Boolean
+startsWith :: Pattern -> String -> Boolean
+startsWith pat = isJust <<< stripPrefix pat
 
 -- | Checks whether the given string ends with the pattern.
 -- |
 -- | ```purescript
 -- | endsWith (Pattern "bar") "foobar" == true
 -- | endsWith (Pattern "foo") "foobar" == false
 -- | ```
-foreign import endsWith :: Pattern -> String -> Boolean
+endsWith :: Pattern -> String -> Boolean
+endsWith pat = isJust <<< stripSuffix pat