Re: [9fans] Typestr usage (inspired by libgeometry)

[arnold@skeeve.com]

Down this path lies C++ constructors and destructors, and likely
additional mess.  For example, stack allocation of a point - who
initializes the members? Etc, etc.

It's probably best not to mess with it, as it's a non-standard
extension.

My two cents.

Skip Tavakkolian <skip.tavakkolian@gmail.com> wrote:

> if you restricted the typestr to integral types (or composition of
> integral types), would there be any garbage collection issues?
>
> On Tue, Dec 16, 2025 at 8:19 AM <ori@eigenstate.org> wrote:
> >
> > Quoth sirjofri via 9fans <9fans@9fans.net>:
> > > Hi,
> > >
> > > I just had a quick thought about using typestr in libgeometry. However, I noticed that typestr is nowhere used in 9front at all (besides the compiler that implements it as a feature).
> > >
> > > Thinking about how typestr provides pretty cool syntactic sugar, I was wondering why that's the case? Is there a goal to maintain the C standard as far as it makes sense, or is it compatibility between plan 9 systems?
> > >
> > > Before thinking about it too much, I just ask here.
> > >
> > > I personally only use it in some cases where it makes sense, in cases similar to the complex number example I was able to find online[1]. I don't think it should be used to hide things, just to provide the ability to write code that's easier to read and understand. For example, instead of combining matrices using functions, I could just type S * R * S, or to add vectors, I can just V + W. For plan 9, adding Points would be trivial.
> > >
> > > Note that I'm _not_ proposing to update all of the routines to use this feature. I'd just like to know your thoughts about using it (or not using it).
> > >
> > > sirjofri
> > >
> > > [1] https://github.com/henesy/plan9-typestr/blob/master/typestr.md
> > >
> > 
> > It's a subtly wrong feature -- it looks cute, but doesn't
> > generalize well in C. Finishing it would imply garbage
> > collection (or at least destructors), which have their
> > own disadvantages.
> > 
> > It may work for some things. This, for example, is fine:
> > 
> > typestr mpint ...;
> > 
> > mpint *x = mpnew(42);
> > mpint *y = mpnew(123);
> > mpint *z = x * y; //ok, fine
> > mpfree(x);
> > mpfree(y);
> > 
> > but what about:
> > 
> > mpint *x = mpnew(42);
> > mpint *y = mpnew(123);
> > mpint *z = x * (y - x) * (y - x);
> > mpfree(x);
> > mpfree(y);
> > 
> > There are intermediate expressions along the way
> > which would need to be allocated; who frees them?
> > 

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