Nicolas Pouillard wrote:
Excerpts from Edward Kmett's message of Fri Oct 09 20:04:08 +0200 2009:
I have idiom brackets in that toy library already, but the ado syntax is fairly useful if you want to refer to several intermediate results by name. To work with idiom brackets you need to manually write a big lambda yourself and them apply it. If you have a lambda that takes several arguments -- which isn't all that uncommon in a parser! -- the names you are binding and their position in the input can get rather far apart, even using idiom sugar. Philippa's ado sugar lets you amortize that big binding statement over several lines and keeps the names closer to the binding.
You can still name intermediate *computations* using local bindings, right? Then you just have to use the named computations in idioms brackets.
Not really good enough, because of all the computations whose results aren't used. Being able to tell at a glance which bits of the parser are handling data for the abstract syntax and which're structure to guide the parser is pretty handy. -- flippa@flippac.org