Re: [Haskell-cafe] combinators for a simple grammar

6 Aug 2007

      On Monday 06 August 2007, Rahul Kapoor wrote:
...
I am having problems coming up with nice combinators for a simple
DSEL. The abstract syntax is simply given by the types:
<snip>
...
Or is it a better idea to just remove the precedence rules from the
types and move it the part of the code that evaluates the expressions?
Exactly thus.  Say:

data SearchCondition
  = Constant Bool
  | SearchCondition :||: SearchCondition
  | SearchCondition :&&: SearchCondition

infixr 3 (:&&:)
infixr 2 (:||:)

And you're set.

Jonathan Cast
http://sourceforge.net/projects/fid-core
http://sourceforge.net/projects/fid-emacs