Elisp

http://lisp-lang.org/style-guide/

• variable naming
  

  • *earmuff* style for mutable globals?
    

  but:
  

  • dynamic variables have a prefix
    
  • local variables (or anything set with a let) do not have a prefix
    
• prefer when cond to if cond ..., prefer unless cond to if (not cond)
  
• predicates
  end with p or -p
  
• doesn't have namespaces. package--private-function package-public-function
  

cursor point region http://ergoemacs.org/emacs/elisp_cursor_position.html
http://ergoemacs.org/emacs/elisp_editing_basics.html

http://ergoemacs.org/emacs/elisp_optional_params.html

&optional prams.
&rest remaining params

no named params, no type checking..

thing-at-point

A cleaner approach to regular expressions in Emacs, as most package maintainers will tell you, is to use the rx library instead. rx translates regular expressions in sexp form to a regexp string:

Function: add-text-properties start end props &optional object
This function adds or overrides text properties for the text between start and end in the string or buffer object. If object is nil, it defaults to the current buffer.

jesus

https://www.reddit.com/r/orgmode/comments/d6wzkr/how_to_locate_the_variable_i_need/

The way I deal with these things: if it's not immediately searchable on stackoverlow, I wouldn't bother doing web search.
My thinking would be:
Ok, what builting org function could possibly use number of stars? Right, when I promote/demote the subtree it must be using that at some point.

small tutorial for hacking on emacs?

Yes, it's generally slower because it checks every heading with predicates. The tradeoff is that the code is more composable and understandable than the 5-screens-long functions in org-agenda.el. Even so, for a lot of use cases, it's fast enough already. There is already a per-buffer, per-query cache that makes performance fast on repeated queries in unchanged buffers, which helps a lot.

    One cool trick that elfeed implements is JIT-compilation of search queries. If you call a function in a map or a loop or something similar this makes a difference.
Yeah, I learned that trick from Chris's code. Both the "predicate" function and "action" function are byte-compiled before running the "query".

https://github.com/bbatsov/emacs-lisp-style-guide

I mean.. ok, but nothing super remarkable idk?
should do a similar demo in python, for example

(elt "arst" 2)

nth element of string