[Template-haskell] RE: Documentation fix for TH example

Gregory Wright gwright at comcast.net
Tue Feb 3 13:19:16 EST 2004


On Feb 3, 2004, at 10:58 AM, Simon Peyton-Jones wrote:

> All true!  Good suggestions.
>
> Are you getting on all right with TH now.  The mailing list has been
> rather quiet recently.
>
> Simon
>


Hi Simon,

I'm starting to understand TH and I've been able to make all the 
examples
people have given me compile on 6.2. This is good progress.

My recent interest in TH began with a question I posted to the 
haskell-cafe
list, asking what was the best way to handle fields in a buffer. (I 
spend a lot of
time looking at IP packets.) Mikael Brockman suggested looking at 
Erlang's
bit syntax. Tomasz Zielonka posted his code which uses TH to generate 
the
boilerplate for handling byte fields in arrays.

I'm starting from Tomasz's code but will add bit fields. I'll also have 
to add handling
for mutable arrays.

Tomasz's code uses parsec, which I'd never bothered to learn parsec so 
I spent
part of the weekend doing the examples in the user guide. Tomasz's 
deserialization
package is a good starting point, and I hope to have something soon. On 
the
other hand, we have a six week old daughter, and while she is quite 
'functional'
(unique outputs for every input), she still has trouble with emacs. 
Perhaps we should
have started her with vi.

It appears as if people are happy to answer TH questions on the ghc-* 
or haskell-cafe
lists. Perhaps inquiries could be directed there and the TH list used 
for announcements?

Best Wishes,
Greg



> | -----Original Message-----
> | From: glasgow-haskell-bugs-bounces at haskell.org
> [mailto:glasgow-haskell-bugs-
> | bounces at haskell.org] On Behalf Of Gregory Wright
> | Sent: 29 January 2004 22:04
> | To: glasgow-haskell-bugs at haskell.org
> | Subject: Documentation fix for TH example
> |
> |
> | Hi,
> |
> | The GHC 6.2 User's Guide has some misleading information w.r.t.
> | template haskell.
> |
> | It still uses Expr instead of ExpQ. It refers to Tim Sheard's notes,
> | but doesn't have the link
> |
> | http://research.microsoft.com/~simonpj/tmp/notes2.ps
> |
> | It should also warn that not all of the features discussed in the
> above
> | notes are implemented.
> | In particular, the way to get TH is still to import
> | Language.Haskell.THSyntax, not Language.Haskell.TH.
> |
> | The example doesn't compile under 6.2. The attachment corrects this.
> |
> | A note that TH is rapidly evolving and that the API is likely to
> change
> | incompatibly between
> | compiler releases might not be out of place either. (I know that such
> | warnings are present
> | in the literature and in some places on the mailing list, but 
> language
> | users who are not
> | part of the FP community look to the documentation first.)
> |
> | Best Wishes,
> |
> | Greg
> |
> | Gregory Wright
> | Antiope Associate LLC
> | 18 Clay Street
> | Fair Haven, New Jersey 07704
> |
> | gwright at antiope.com
> |
>
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