Re: implementation language [was: library for unicode collation in C for texi2any?]

[Per Bothner]

On 10/15/23 05:41, Gavin Smith wrote:
> texi2any is full of code like this:
>
>       if ($target_element->{'extra'}
>            and $target_element->{'extra'}->{'unit_command'}) {
>          if ($target_element->{'extra'}->{'unit_command'}->{'cmdname'} eq 
> 'node') {
>            $command = $target_element->{'extra'}->{'unit_command'};
>          } elsif ($target_element->{'extra'}->{'unit_command'}->{'extra'}
>                   and $target_element->{'extra'}->{'unit_command'}
>                                            ->{'extra'}->{'associated_node'}) {
>            $command = $target_element->{'extra'}->{'unit_command'}
>                                            ->{'extra'}->{'associated_node'};
>          }
>        }

I'm far from a C++ expert these days, but some ideas:

* First of course you can define some helper methods:

class TargetElement {
  Extra *extra;
  Command *unit_command() { return extra ? extra->init_command() : nullptr; }
}

* Declarations in 'if' statement:

if (auto unit_command = target_elememt->unit_command()) {
    if (unit_command->cmdname() == "node") ...
}

* Some kind of smart pointer may be useful.
However, I don't really have a good handle on smart pointer,
and I don't know if this further than you want to go in terms of C++-isms.
I can do some research, though.

* Perhaps use a subclass for the "extra" fields:

class TargetElementWithExtra :: TargetElement {
    Command *unit_command;
}

if (auto te = dynamic_cast<TargetElementWithExtra*>(target_element)) {
    // te is target_element safely cast to TargetElementWithExtra*.
}
--
        --Per Bothner
per@bothner.com   http://per.bothner.com/