I was developing this project of mine, which has an intricate business logic, and I wrote a macro that makes programming this kind of stuff more comfortable. It's called "ilet", which stands for "implicit let". The name is probably no longer appropriate, since I added more features to it, but I can't make up anything better right now.
I'd really appreciate it if you could dissuade (or persuade) me from posting this to clojure-dev for inclusion in contrib. I need to know if this could be useful to someone besides me. Here's the rationale of the ilet macro. (Warning: the examples are silly. See below for a real world example.) We have "->" in Clojure because it lets you do dataflow-programming- like manipulations. The first version of ilet was used in a similar way, but it simply bound a symbol ($). It works like "->" but it's more flexible, because you can put the value of the previous expression wherever you want (e.g., see http://pastebin.com/g7k8wK4a). This is nice, but it's often useful to bind symbols explicitly. Using a "let" inside an "ilet" is clunky, so I added this capability inside "ilet" itself. If you write [symbol] [expression], ilet interprets that as an explicit binding (see http://pastebin.com/2VJ8D738). Finally, I wanted to be able to interrupt this kind of calculations. Unfortunately, Clojure doesn't provide any return-like constructs: you'd need to use if's and cond's. So I added a new syntax to ilet: "<" [condition] [expression] where if [condition] is true, the value of the whole ilet expression is just [expression] (see http://pastebin.com/np2M9kZr). I hope my explanation was clear, in spite of my poor English. This is the definition of the ilet macro: http://pastebin.com/nHLifsu3 And this is a real world example, straight from my repository: http://pastebin.com/xGQT1c5h Thank you all for your input! -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
