[Haskell-cafe] Re: What are side effects in Haskell?

"Reiner Pope" wrote:

2009/1/3 Conal Elliott :

...

Are there other thoughts & insights about the source of the idea that "everything is a function"?

Lazy evaluation can make values seem like functions, given that laziness can be modeled in a strict imperative language by 0-argument functions.

Also, in an uncurried language, decreasing the number of arguments to a function, still keeps it a function, eg foo(int a, int b); // 2 arguments foo(int a); // 1 argument foo(); // 0 arguments, but still a function In a strict language, there is a distinction between 0-argument functions and values; there isn't in Haskell, but it is still nice to maintain the idea of "0-argument functions" in Haskell -- which are just values.

You can factor a cool intuitive understanding about IO actions not being the action itself, but just tokens that represent an action, out of this, by adding just one sentence. I guess the proper way to offset functions and values depends on what you want to explain, and multiple views on the same thing can't hurt. Conal, you aren't interrogating the list to figure out how to write a Haskell version of the wizard book, are you? We'd have to stop the pizza deliveries if you stop working on reactive... ;) -- (c) this sig last receiving data processing entity. Inspect headers for copyright history. All rights reserved. Copying, hiring, renting, performance and/or quoting of this signature prohibited.