Suggestions from HN

[engelju]

Since it peaked on HN1 a few hours ago, there were some suggestions on things we could improve:

From mjburgess:

These definitions don't really give you the idea, rather often just code examples..
"The ideas", in my view:

Monoid = units that can be joined together

Functor = context for running a single-input function

Applicative = context for multi-input functions

Monad = context for sequence-dependent operations

Lifting = converting from one context to another

Sum type = something is either A or B or C..

Product type = a record = something is both A and B and C

Partial application = defaulting an argument to a function

Currying = passing some arguments later = rephrasing a function to return a functions of n-1 arguments when given 1, st. the final function will compute the desired result

EDIT: Context = compiler information that changes how the program will be interpreted (, executed, compiled,...)

Eg., context = run in the future, run across a list, redirect the i/o, ...

From ncmncm:

1. It should explain map somewhere before it is used.

2. For the more abstruse and abstract concepts, a comment suggesting why anybody should care about this idea at all would be helpful. E.g., "A is just a name for what [familiar things] X, Y, and Z have in common."

3. It goes off the rails halfway through. E.g. Lift.

From sanderjd:
Expanding on your #1, I think they could use some more definitions. As you say, they use "map" in its functional programming sense before defining it, but I think more confusing is this one:

A category in category theory is a collection of objects and morphisms between them.

What is a "morphism"?

I think this is a great starting point though, which could use some expansion.

[jethrolarson]

Thanks for sharing!

It should explain map somewhere before it is used.

I keep going back and forth on this. Like is this fundamentally a glossary or something you read straight through? Also I fear there are some concepts which I think would prevent a sensical order. There is also the fact that changes to this document come from many people so maintaining a coherent flow hasn't happened.