> On 15 Mar 2024, at 03:57, Mark Devine <m...@markdevine.com> wrote:
>
> Rakoons,
> I keep running into a space with Raku where it would be nice to have some
> magic to reduce boilerplate. I often make roles & classes with interface
> options that flow from a consuming script’s MAIN arguments, then the first
> bit of code at the top the MAIN block, then into instantiation. If a person
> makes nice utility libraries with lots of options for the user & employs them
> a lot, the time consumed typing out the boilerplate adds up & bloats the
> code. Is there any way to shorten this pattern? I was thinking about a
> ‘switchable’ trait for attributes (with the naivety of a schoolboy).
> my class Output {
> has $.csv is switchable;
> has $.html is switchable;
> .
> .
> .
> has $.xml is switchable;
> }
> my class Timer {
> has $.count is switchable;
> has $.expire is switchable;
> has $.interval is switchable;
> }
> sub MAIN (
> Output.switchables, #= switchables from Class 'Output'
> Timer.switchables, #= switchables from Class 'Timer'
> ) {
> my Timer $t .= new: :$expire, :$interval, :$count; # variables
> magically appear in scope
> my Output $o .= new: :$csv, :$html, … , :$xml; # variables
> magically appear in scope
> }
> I estimate 10-50 lines of boilerplate could be removed from most of my Raku
> scripts with something like that. Unfortunately, I don’t possess any dark
> magic for such things or I’d put forward an attempt.
An interesting idea!
Unfortunately I don't see this happening in the legacy grammar. And it may
still be pretty hard to do in RakuAST.
If you'd want to have a solution now, I'd look at *generating* the boilerplate
code where appropriate. This approach is used in the core in several
locations, most notably recently in the localization modules.
Liz
