[Vm-dev] [Vm-beginners] Stability of the external plugin interface

[tim Rowledge]

> On 2020-05-25, at 10:25 AM, K K Subbu <kksubbu.ml at gmail.com> wrote:
> 
> On 25/05/20 5:04 pm, Jakob Reschke wrote:
>> If a library breaks compatibility, you would have to update the plugin and maybe think about how to stay compatible with older Squeaks. If it were FFI with a proper facade that finds out how to link to the external library, you would need to update the facade and worry there about staying compatible, but you could do it in Smalltalk. It requires discipline and guidance to only use the facade, of course.
> Libraries like OpenGL are frustrating because of poorly abstracted, low level functions. Trying to stable facade around its warts will not solve the core problem of having to deal with static code and compile cycles.
> 
> The frustration is having to regress from live programming into code-compile-link-test cycle in 2020! Given a choice between live programming and backward compatibility, I would choose live programming because I can close any gaps through live coding.


Nicely put.
> 

> For instance, a few years back I developed live previews for LaTeX without leaving Squeak (Etoys) by using OSProcess to build a LaTeX pipeline that converted code into image as the code was being typed. It is an inefficient design but it took just half a day and has served well over the years.
> 
> But this was at process level. If only I could do the same with DLLs. If only Squeak had a tool (ELF reader?) to reify a DLL, extract its instruction set, interface definitions, state variables and calling conventions. Then I can livecode a class and dynamically compile it (now that we have JIT) to call functions DLL without leaving the image. The code may not be 'portable' in traditional sense. But it will be a lot more manageable than static designs.


VW has a parser of C header files that is I suppose the right way to do this sort of thing - you parse the headers (warning - I seem to recall parsing 'windows.h' taking several days in the original VW ddl product) and build proxies of all the types/structs/etc.  Is that a practical way to do it? Hell of a lot of work to do, certainly.

tim
--
tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
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