dash.el [was: Re: Imports / inclusion of s.el into Emacs]

[Joost Kremers]

On Fri, May 08 2020, Alfred M. Szmidt wrote:
>      > My guess: he doesn't know dash.el 
>
> Neither do I, I looked it up.  
>
> The manual for dash.el doesn't explain what dash.el is about, it
> advertises it self as a 'modern list library for Emacs'.
>
> From the looks it contains a big mix of various functions that 
> operate
> on lists, anaphoric variants of Emacs lisp ones, some functions
> borrowed from Haskell, some functions to work on tree, and a 
> thin
> layer for various Emacs Lisp functions to follow the dash.el 
> libraries
> internal naming converntion of prefixing everything with a dash, 
> and
> the Scheme naming style for predicate.  At the end, I still do 
> not
> know what dash.el does, 

But you just described what dash does. ;-) It is just a collection 
of list-handling functions such as they exist in modern functional 
programming languages. If you're used to thinking in this paradigm 
and then come (back) to Emacs Lisp, it feels like a hopelessly 
clunky language. `dash.el` was written to remedy this.

I assume the short prefix was chosen because list handling 
functions are part of the core language in Clojure (and I assume 
other functional programming languages) and using a dash was the 
best way to not conflict with existing names and still create the 
feeling that you're not actually using a library. (I assume 
"easier to type" won't have much to do with it, we have 
completion, after all.)

The convention of using `?` for predicates is probably also 
borrowed more from Clojure than from Scheme (though Clojure 
obviously borrowed it from Scheme).

> or what to use it for.

Well, you use it if you want to program in a Clojure-like style.


--
Joost Kremers
Life has its moments