Le 26 sept. 11 à 18:44, Gabriel Scherer a écrit :
Phantom types could be a solution but we must declare a new type for
each possible size, which is cumbersome / annoying.
If you define the type system yourself, you can easily add a family of
type constants `sizen` (with `n` an integer
Le 26 sept. 11 à 14:45, Yaron Minsky a écrit :
As written, the behavior of the types might not be what you expect,
since addition of two 16 bit ints may result in an int that requires
17 bits.
In the current situation, this will be handled at the VHDL level.
Making it explicit at CAPH
You're perfectly right Christophe,
I now realize that i've opened some kind of Pandora box.
Supporting function declaration
concat : intn - intm - intn+m (or multiplication)
would be great (even with only addition on sizes), but a too long
term goal for me (esp. taking into account that
Yes, this is right. You can already experiment in ocaml, as Denis
Berthod suggested, by adding abstract types by hand instead of having
constants in the initial environment.
You can also embed the natural numbers in Ocaml's type system by declaring
the following two types:
type 'a s
type z
That's pretty cool, everyone and his mother has a solution to the proposed
problem.
I think, for the sake of exhaustivity, i can share my own weird hack.
It can express all power of 2 sizes (for example add, mul and div).
It uses a nested data type.
type 'a size =
| Word of 'a
| DWord
Sorry,
foo = add
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As written, the behavior of the types might not be what you expect, since
addition of two 16 bit ints may result in an int that requires 17 bits.
When using phantom types, you need to be especially careful that the types
mean what you think they mean.
On Sep 26, 2011 8:13 AM, Denis Berthod
Thanks to all for your answers.
Phantom types could be a solution but we must declare a new type for
each possible size, which is cumbersome / annoying.
Moreover, since i'm writing a DSL, the fact that they do not require a
modification to the existing type system is not really an
Phantom types could be a solution but we must declare a new type for
each possible size, which is cumbersome / annoying.
If you define the type system yourself, you can easily add a family of
type constants `sizen` (with `n` an integer literal) to the default
environment of the type checker.
On Mon, Sep 26, 2011 at 01:42:51PM +0200, Jocelyn Sérot wrote:
Hello,
I've recently come across a problem while writing a domain specific
language for hardware synthesis
(http://wwwlasmea.univ-bpclermont.fr/Personnel/Jocelyn.Serot/caph.html
[...]
Very interesting.
I also once thought
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