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

[Gavin Smith]

On Sat, Oct 14, 2023 at 01:49:26PM -0700, Per Bothner wrote:
> On 10/14/23 09:12, Patrice Dumas wrote:
> > On Thu, Oct 12, 2023 at 10:25:23AM -0700, Per Bothner wrote:
> > > C++ has a more extensive and useful standard library than C.
> > 
> > I guess there is an hash map, but I am not sure that we would need much
> > more.
> 
> In addition to hash maps and maybe some other container classes,
> I suggest using C++ std::string as being safer and more convenient that C 
> strings.
> 
> > I am not a good judge, but it is unclear to me that the rewriting in
> > perl was a mistake, it allowed to have the current design, which I
> > believe is much better than the design of makeinfo in C had.  It is
> > easier to redesign in a high level language and then translate the parts
> > than need to be sped up to a low level language than do everything in a
> > low level language.
> 
> I think C++ is about as high-level as Perl, and I think you can
> write programs that as similarly concise and legible.
> My hunch is that tp/Texinfo written in C++ would be at most a small amount 
> (20% ?)
> more verbose, and to many (including myself) it would be much more readable.

A language that has an "optional chaining" operator would make some texi2any
code much more concise:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining

https://en.wikipedia.org/wiki/Safe_navigation_operator

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'};
        }
      }


It would be much nicer if it looked like this (imaginary PL syntax):

    if (target_element.extra?.unit_command?.cmdname eq 'node') {
      command = target_element.extra.unit_command
    } elsif (target_element.extra?.unit_command?.extra?.associated_node) {
      command = target_element.extra?.unit_command?.extra?.associated_node
    }

The closest thing to this is JavaScript AFAIK.

However, rewriting texi2any from Perl to JavaScript would be a huge undertaking
that would offer no value for the end user.