001    package fj.function;
002    
003    import fj.F;
004    import fj.F2;
005    import static fj.Function.curry;
006    
007    /**
008     * Curried string functions.
009     *
010     * @version %build.number%<br>
011     *          <ul>
012     *          <li>$LastChangedRevision$</li>
013     *          <li>$LastChangedDate$</li>
014     *          </ul>
015     */
016    public class Strings {
017      private Strings() {
018        throw new UnsupportedOperationException();
019      }
020    
021      /**
022       * A curried version of {@link String#isEmpty()}.
023       */
024      public static final F<String, Boolean> isEmpty = new F<String, Boolean>() {
025        public Boolean f(final String s) {
026          return s.length() == 0;
027        }
028      };
029    
030      /**
031       * A curried version of {@link String#length()}.
032       */
033      public static final F<String, Integer> length = new F<String, Integer>() {
034        public Integer f(final String s) {
035          return s.length();
036        }
037      };
038    
039      /**
040       * A curried version of {@link String#contains(CharSequence)}.
041       * The function returns true if the second argument contains the first.
042       */
043      public static final F<String, F<String, Boolean>> contains = curry(new F2<String, String, Boolean>() {
044        public Boolean f(final String s1, final String s2) {
045          return s2.contains(s1);
046        }
047      });
048    
049      /**
050       * A curried version of {@link String#matches(String)}.
051       * The function returns true if the second argument matches the first.
052       */
053      public static final F<String, F<String, Boolean>> matches = curry(new F2<String, String, Boolean>() {
054        public Boolean f(final String s1, final String s2) {
055          return s2.matches(s1);
056        }
057      });
058    
059    }