F# and Concurrent Clean introduced special syntax for doing this. Basically they just invent new names for you. In Haskell (warning: I'm a newbie, so take this with a grain of salt), I guess you just use monads if you want to pass a value from one function to another under some context, or you could just make your own little much simpler combinator like: infixl 0 \> -- I just took the first weird symbol combination that came to mind, this does not mean anything (I hope ;-) x \> fx = fx x f x = x * scale \> \x -> x + transform \> \x -> g x like this you don't have to invent new names, and you don't have to type much more. I'm sure this silly sequencing operator must already exist in the library somewhere? -----Original Message----- From: haskell-cafe-bounces@haskell.org [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of Peter Hercek Sent: Thursday, August 30, 2007 6:18 PM To: haskell-cafe@haskell.org Subject: [Haskell-cafe] let and fixed point operator Hi, I find the feature that the construct "let x = f x in expr" assigns fixed point of f to x annoying. The reason is that I can not simply chain mofifications a variable like e.g. this: f x = let x = x * scale in let x = x + transform in g x When one is lucky then it results in a compile error; in worse cases it results in stack overflow in runtime. The annoying part is figuring out new and new variable names for essentially the same thing to avoid the search/evaluation of the fixed point. I suppose Haskell was designed so that it makes sense. The only usage I can see is like this: let fact = \x -> if x == 0 then 1 else x * fact (x-1) in ... but that is not any shorter than: let fact x = if x == 0 then 1 else x * fact (x-1) in So the question is what am I missing? Any nice use cases where fixed point search is so good that it is worth the trouble with figuring out new and new variable names for essentially the same stuff? Peter. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe