Are there any differences between Select and Map? if not why include Map in this library

[RollsChris]

Hi

I cant see any difference between Select and Map Implementation when reading the docs?

Why include Map? I think it adds more confusion when we already have Select

Thanks

[StefanBertels]

This is not my library so maybe the following answer is a guess.

But from what I learned by using the library and sometimes diving into details, the main reason is probably that map, filter, bind, fold etc are common names for those FP operations outside of C#. As a lot of concepts in LanguageExt try to bring FP into "C# world" this makes it a lot easier to understand concepts and to communicate with others.

Probably the name choice in C# (select, where, selectmany, aggregate) was unfortunate from today's FP perspective -- it was heavily inspired by SQL terminology. But that's history.

For practical reasons LanguageExt types supports C# select, where ...., too. This enables LINQ style -- which is a good fit here, because LINQ is a very functional (FP) concept in C# and it is very useful with LanguageExt.

There might be more technical reasons because of implementation differences between .Bind and .SelectMany (latter includes projection) or different (more) signatures for .Map in comparison to .Select (e.g. iterating over (key,value) or (index,value)).

[RollsChris]

I kind of thought that would be the case but it does make the landscape a whole lot more confusing lol

[louthy]

@StefanBertels is correct, Select, SelectMany, and Where are SQL terminology, not FP terminology. If I could get away with just Map, Bind, and Filter I would, but Select, SelectMany, and Where are needed to make the monadic types work in LINQ expressions.