[Info-vax] Pascal question

[John Reagan]

On Wednesday, January 23, 2019 at 11:06:00 AM UTC-5, Brian_R wrote:
> On Wednesday, January 23, 2019 at 3:00:15 PM UTC, Arne Vajhøj wrote:
> > On 1/22/2019 2:58 AM, Brian_R wrote:
> > > On Tuesday, January 22, 2019 at 1:44:04 AM UTC, John Reagan wrote:
> > >> As for string manipulation, like upcase, it hasn't been a popular
> > >> request.
> > > 
> > > Why would it be, its handled quite nicely by the OS libraries. I use
> > > VMS Pascal on a daily basis and we use STR$xxxxx for standard string
> > > handling.
> > 
> > I still think builtin Pascal functions would be nicer.
> > 
> > > Now additional routines (RTL preferred) for the manipulation of JSON
> > > structures might be a plan.
> > 
> > Given that VMS Pascal AFAIK does not support any type of reflection,
> > then there are heavy constraints on what is possible.
> > 
> > Do you basically just need a good parser that makes it easy to do:
> > 
> > JSON string---(generic parser)--->generic data structure---(custom 
> > code)--->custom data structure
> 
> A generic parser would be fine. We effectively hand-rolled our own JSON-RPC interface using a standard C parser (called from Pascal) which returned a tree structure of json objects which we could iterate through using Pascal wrappers. 
> 
> LIB$FIND_IMAGE_SYMBOL was then used to find the RPC function in the library and the target Pascal routine called via LIB$CALLG. It worked and made it reasonably simple to extend, especially over the binary formats we'd been using previously.
> 
> The list of available routines and their parameters was stashed in a JSON configuration file.
> 
> > 
> > ?
> > Arne

function types and function pointers is one of the missing pieces of Pascal that you get in C.  I almost added them years ago about the time I moved over to NonStop.