Comments on: Y Combinator in Java With Generics http://szeiger.de/blog/2007/08/12/y-combinator-in-java-with-generics/ Stefan Zeiger's Software Development Weblog Wed, 17 Mar 2010 13:24:26 +0100 http://wordpress.org/?v=2.8.4 hourly 1 By: Daniel Martin http://szeiger.de/blog/2007/08/12/y-combinator-in-java-with-generics/comment-page-1/#comment-19 Daniel Martin Thu, 28 Feb 2008 11:17:09 +0000 http://szeiger.de/blog/2007/08/12/y-combinator-in-java-with-generics/#comment-19 Ugh. That was supposed to be: So that Function<String,Integer> is a function that takes a String as a parameter, and returns an Integer. Unfortunately, I had no way of knowing whether this blog accepted html in the comments and no way of previewing my comment before I made it. Ugh. That was supposed to be:
So that Function<String,Integer> is a function that takes a String as a parameter, and returns an Integer.

Unfortunately, I had no way of knowing whether this blog accepted html in the comments and no way of previewing my comment before I made it.

]]> By: Daniel Martin http://szeiger.de/blog/2007/08/12/y-combinator-in-java-with-generics/comment-page-1/#comment-18 Daniel Martin Thu, 28 Feb 2008 11:14:53 +0000 http://szeiger.de/blog/2007/08/12/y-combinator-in-java-with-generics/#comment-18 You can go further with the annotations - it's possible to do it entirely with annotations and no casting (I note that you need to do a cast to R and a cast to F in your version). What you need to do to do this is to define a recursive type. I show how here: http://dtm.livejournal.com/36832.html I use the interface com.google.common.base.Function, which is like F except that the single method is called "apply" and the order of the type parameters are switched. (So that Function is a function that takes a String as a parameter, and returns an Integer) You can go further with the annotations – it’s possible to do it entirely with annotations and no casting (I note that you need to do a cast to R and a cast to F in your version). What you need to do to do this is to define a recursive type.

I show how here: http://dtm.livejournal.com/36832.html

I use the interface com.google.common.base.Function, which is like F except that the single method is called “apply” and the order of the type parameters are switched. (So that Function is a function that takes a String as a parameter, and returns an Integer)

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