Comments on: Project Euler Problem 2 Functional Java http://blog.tmorris.net/project-euler-problem-2-functional-java/ The weblog of Tony Morris Tue, 07 Feb 2012 18:26:57 +0000 http://wordpress.org/?v=2.6 By: Vladimir http://blog.tmorris.net/project-euler-problem-2-functional-java/#comment-21620 Vladimir Thu, 30 Oct 2008 16:57:22 +0000 http://blog.tmorris.net/?p=369#comment-21620 I was always wondering why no one is using symbol "$" for function application when creating a lambda supporting library for Java. <code> Function<Long, String> longToStr = StringUtils.toStr(); Function<Long, Boolean> hasNo245680 = new Function<Long, Boolean>(){     public Boolean $(Long l) {         String s = l.toString();             return s.indexOf('2') == -1                 && s.indexOf('4') == -1                 && s.indexOf('5') == -1                 && s.indexOf('6') == -1                 && s.indexOf('8') == -1                 && s.indexOf('0') == -1;     } }; primes = ListUtils.<Long>filter().$(hasNo245680).$(primes); Set<String> primesSet = new HashSet<String>(     ListUtils.<Long, String> map().$(longToStr).$(primes) ); </code> I was always wondering why no one is using symbol “$” for function application when creating a lambda supporting library for Java.


Function<Long, String> longToStr = StringUtils.toStr();
Function<Long, Boolean> hasNo245680 = new Function<Long, Boolean>(){
    public Boolean $(Long l) {
        String s = l.toString();
            return s.indexOf('2') == -1
                && s.indexOf('4') == -1
                && s.indexOf('5') == -1
                && s.indexOf('6') == -1
                && s.indexOf('8') == -1
                && s.indexOf('0') == -1;
    }
};
primes = ListUtils.<Long>filter().$(hasNo245680).$(primes);
Set<String> primesSet = new HashSet<String>(
    ListUtils.<Long, String> map().$(longToStr).$(primes)
);

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