[m-users.] Parsing source files / tem-rewriting

[Volker Wysk]

Am Freitag, dem 16.08.2024 um 08:05 +0100 schrieb Sean Charles
(emacstheviking):
> Agreed. It is without doubt the hardest language I have ever learned, I
> still struggle with it at times, and the code I write is probably 'awful'
> as I don't fully grok all the concepts to the Nth degree, solver types for
> example.... whooooosh straight over the top of my head.

I've googled a little. There doesn't seem to be a shortage of tutorials on
constraint programming.

> What Mercury has provided me with is a means to help me think hard about
> the problem at hand, and then give me a rock solid basis on which to
> implement the solution with its types, type-classes. 

Yes, formulating the problem in Mercury means understanding it. 

> I've used the sub-types here and there but I find they sometimes make
> things harder, again, probably down to my lack of formal education in
> 'logic programming.

I haven't used subtypes, or solver types yet. 

Bye,
Volker

> 
> All the best and thanks again to "Team Core Mercury"!
> 
> > On 16 Aug 2024, at 07:04, Volker Wysk <post at volker-wysk.de> wrote:
> > 
> > 
> > Am Freitag, dem 16.08.2024 um 06:37 +0100 schrieb Sean Charles
> > (emacstheviking):
> > > Yes, there is something *special* that Mercury does to your mind!
> > 
> > 
> > I think it's its strictness and cleanness - the logic programming
> > paradigm, with modes and determinism categories... And the type system
> > too...
> > 
> > Cheers,
> > Volker
> > 
> > > 
> > > > On 15 Aug 2024, at 16:26, Volker Wysk <post at volker-wysk.de> wrote:
> > > > 
> > > > Hi, Sean!
> > > > 
> > > > I see, you've adopted the philosophy "Don't give in until it's done
> > > > right." 
> > > > 
> > > > That's not bad, I've adopted it too, not very long ago. It was after
> > > > I've learned Mercury.
> > > > 
> > > > Keep hacking, and make that transpiler of yours a success. :-)
> > > > 
> > > > Cheers,
> > > > Volker
> > > > 
> > > > 
> > > > Am Donnerstag, dem 15.08.2024 um 07:29 +0100 schrieb Sean Charles
> > > > (emacstheviking):
> > > > > 
> > > > > 
> > > > > > On 15 Aug 2024, at 04:18, Volker Wysk <post at volker-wysk.de>
> > > > > > wrote:
> > > > > > 
> > > > > > Am Mittwoch, dem 14.08.2024 um 19:19 +0100 schrieb Sean Charles
> > > > > > (emacstheviking):
> > > > > > > Yes, I have resisted the urge to use it, Uncle Bens rule
> > > > > > > applies here!  :D
> > > > > > 
> > > > > > Hmm... I couldn't find out what Uncle Ben's rule is.
> > > > > 
> > > > > 
> > > > > Ah, it's from a Spiderman movie:
> > > > > "
> > > > > <DreamHaven_May_30_2020_storeboards.jpg>With great power comes
> > > > > great responsibility
> > > > > en.wikipedia.org
> > > > > 
> > > > > "
> > > > > 
> > > > > https://en.wikipedia.org/wiki/Uncle_Ben
> > > > > Sorry!
> > > > > 
> > > > > > 
> > > > > > > I am working on a FORTH engine in Mercury right now, it's
> > > > > > > going well, it
> > > > > > > will basically expose the strictness of Mercury through a
> > > > > > > stack based
> > > > > > > system... currently the core words are hand assembled but they
> > > > > > > have a very
> > > > > > > common pattern so far, and when the dust settles I think there
> > > > > > > MIGHT be a
> > > > > > > case for term rewriting to create that data.
> > > > > > 
> > > > > > You have a lot of projects. But what would you want to do with a
> > > > > > Forth
> > > > > > engine? Is it just for the fun of programming? ;-)
> > > > > 
> > > > > 
> > > > > Well, a loooooooong time ago I wrote this, felt-lang.com, since
> > > > > then I have rewritten it in Haskell, SWI-Prolog and C as POCs but
> > > > > wasn't hasppy, then the Universe showed my Mercury. It's been a
> > > > > very rewarding journey since and lots of what I have learned has
> > > > > filtered into my daily coding, mostly improved rigour in thinking
> > > > > about things.
> > > > > 
> > > > > The concept of  a transpiler is not new, I've used HaXe in the
> > > > > past, but *I* have never written one, currently the Mercury
> > > > > version parses s-expressions into working C code, which compiles,
> > > > > but the more I got into the weeds, the more I realised that I
> > > > > wanted a faster REPL based interactive/explorative environment for
> > > > > the code render phase, with the view that users vould use a glue
> > > > > language for the AT-->Code part to do whatever they want with the
> > > > > parsed s-expression tree.
> > > > > 
> > > > > For reasons best known to me3, and to avoid triggering Greenspun's
> > > > > tenth law, I decided I needed a custom FORTH dialect and so now I
> > > > > find myself engaged in hand-to-keyboard, I already have
> > > > > implemented basic stack ops, basic arithmetic, and a bunch of
> > > > > words,
> > > > > 
> > > > > 
> > > > > ➜  mercury-merth git:(main) ✗ ./dstack
> > > > >  > words
> > > > > 
> > > > > System words:
> > > > > * + - -> . .S .SEEVM .STATUS .STRICT / /MOD : ; >IOP >IOW BYE
> > > > > CLEARSTACK CONSTANT CR DROP DUP ELSE EMIT ENDIF IF MOD OVER
> > > > > RECURSE ROT SEE SPACE SPACES SWAP THEN TYPE T{ WORDS }T 
> > > > > 
> > > > > User words:
> > > > > 
> > > > > 
> > > > >  > : hv "Hello Volker!" type cr ;
> > > > > New word defined: hv
> > > > >  > words
> > > > > 
> > > > > System words:
> > > > > * + - -> . .S .SEEVM .STATUS .STRICT / /MOD : ; >IOP >IOW BYE
> > > > > CLEARSTACK CONSTANT CR DROP DUP ELSE EMIT ENDIF IF MOD OVER
> > > > > RECURSE ROT SEE SPACE SPACES SWAP THEN TYPE T{ WORDS }T 
> > > > > 
> > > > > User words:
> > > > > HV 
> > > > > 
> > > > >  > hv
> > > > > Hello Volker!
> > > > >  > 
> > > > > 
> > > > > I implemented the test words, T{ -> }T early on, and I copy the
> > > > > relevant tests from the Forth standards site and so far all
> > > > > passing which feels nice, for example,
> > > > > from https://forth-standard.org/standard/core/IF
> > > > > 
> > > > > "If/Else/Then" suite
> > > > > T{ : GI1 IF 123 THEN ; -> }T
> > > > > T{ : GI2 IF 123 ELSE 234 THEN ; -> }T
> > > > > T{  0 GI1 ->     }T
> > > > > T{  1 GI1 -> 123 }T
> > > > > T{ -1 GI1 -> 123 }T
> > > > > T{  0 GI2 -> 234 }T
> > > > > T{  1 GI2 -> 123 }T
> > > > > T{ -1 GI1 -> 123 }T
> > > > > 
> > > > > 
> > > > > My dialect will expose all the Mercury basic types and modules,
> > > > > the stack only allows int and string at the moment but I have some
> > > > > planned features to allow a Lua like table structure, stack
> > > > > signature checking, there is NO coercion of types, as I say, under
> > > > > the hood I intend to 'expose' Mercurys world view into the
> > > > > dialect, it will be a strict strict puppy that's for sure,
> > > > > 
> > > > > The other feature I've designed is Forth->Mercury, by analysing
> > > > > the stack signatures, I plan to generate raw Mercury code so I use
> > > > > the engine for rapid prototyping of code, then it can be printed
> > > > > and incorporated into my custom IDE as I go, the IDE being written
> > > > > in Mercury too, still on paper that one but heavily inspired by
> > > > > 'that Doug Englebart demo' and the Squeak Smalltalk Morphic
> > > > > engine.
> > > > > 
> > > > > So much to do, so little time.
> > > > > 
> > > > > And, it's *always* for the fun of programming!
> > > > > 
> > > > > :D
> > > > > 
> > > > > Sean
> > > > > 
> > > > > 
> > > > > 
> > > > > > 
> > > > > > Cheers,
> > > > > > Volker
> > > > > > 
> > > > > > > 
> > > > > > > Thanks again.
> > > > > > > Sean
> > > > > > > 
> > > > > > > 
> > > > > > > > On 14 Aug 2024, at 19:16, Volker Wysk <post at volker-wysk.de>
> > > > > > > > wrote:
> > > > > > > > 
> > > > > > > > Am Mittwoch, dem 14.08.2024 um 19:10 +0100 schrieb Sean
> > > > > > > > Charles (emacstheviking):
> > > > > > > > > That's the chap!
> > > > > > > > > 
> > > > > > > > > Thanks Volker, I just could see it, my brain was convinced
> > > > > > > > > it was in a folder!
> > > > > > > > 
> > > > > > > > That thing is ridiculously small, for what it does.
> > > > > > > > 
> > > > > > > > Enjoy it!  :-)
> > > > > > > > 
> > > > > > > > Bye, 
> > > > > > > > V.W.
> > > > > > > > 
> > > > > > > > > > On 14 Aug 2024, at 19:00, Volker Wysk <post at volker-
> > > > > > > > > > wysk.de> wrote:
> > > > > > > > > > 
> > > > > > > > > > Am Mittwoch, dem 14.08.2024 um 18:29 +0100 schrieb Sean
> > > > > > > > > > Charles
> > > > > > > > > > (emacstheviking):
> > > > > > > > > > > Hi,
> > > > > > > > > > > 
> > > > > > > > > > > There was an example of term rewriting but I cannot
> > > > > > > > > > > seem to find it
> > > > > > > > > > > anywhere!
> > > > > > > > > > > 
> > > > > > > > > > > Is there any code I can leverage to scan a .m file and
> > > > > > > > > > > produce an AST or
> > > > > > > > > > > at least scan the terms... I know the rewrite example
> > > > > > > > > > > pretty has all the
> > > > > > > > > > > answers I need but I just can't find it.
> > > > > > > > > > 
> > > > > > > > > > I think you mean samples/expand_terms.m.
> > > > > > > > > > 
> > > > > > > > > > Cheers,
> > > > > > > > > > Volker
> > > > > > > > > > _______________________________________________
> > > > > > > > > > users mailing list
> > > > > > > > > > users at lists.mercurylang.org
> > > > > > > > > > https://lists.mercurylang.org/listinfo/users
> > > > > > > > > 
> > > > > > > 
> > > > > > 
> > > > > 
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