Variant that uses no GHC-specific extensions / functions about vault HOT 7 OPEN

I didn't try it, but ST is in the UHC repository: https://github.com/uhc/uhc/blob/master/EHC/ehclib/base/Control/Monad/ST.hs

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@sjoerdvisscher Nice!

The package now uses GHC-specific extensions only when they are available.

Furthermore, I have included a module Data.Unique.Really that provides unique symbols that can survive a GHCi reload. This is important for type safety!

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For posterity, there is also a package

http://hackage.haskell.org/package/statethread

that implements the ST monad in terms of IORef and can be used with other compilers.

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This variant works fine with UHC.
Only thing I needed to implement was Data.Unique, for which I chose a simple increment_from_0 counter.

I did one extra tweak to vault's codebase: change Integer to Int in Data/Unique/Really.hs
Int is implemented natively in javascript, while Integer (infinite precision) needs a library. This library is not that huge, but I've managed to avoid it until now.

As javascript's Int is 53bit according to the ECMA standard (independent if the host platform is 32 or 64 bit) , this is more than enough for my needs.

But I don't expect vault to follow this, as this might be problematic on a 32bit architecture.

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Great!

We can make a CPP conditional for the Int if you like.

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What would the condition be?

"if UHC" doesn't seem right. I don't know if there's a macro for
UHC/JS, but even then it's probably a bit personal.
It all depends on how many unique's you expect.
Probably for 32bit archs, maxBound is already quite enough.
The only somewhat logical choice is to target UHC/JS specifically.
Just leave it for now, I have small todo/findout list, I'll add
investigating possible macros and get back to you.

On Tue, Apr 10, 2012 at 6:35 PM, Heinrich Apfelmus
[email protected]
wrote:

Great!

We can make a CPP conditional for the Int if you like.

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Reply to this email directly or view it on GitHub:
#5 (comment)

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The only somewhat logical choice is to target UHC/JS specifically.

Yup.

It's indeed rather narrow, but I am beginning to learn that sometimes, putting workarounds in the official branch can make life easier. (Had that problem with compilation of reactive-banana on GHC 7.2)

Just leave it for now, I have small todo/findout list,

Ok.

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