Re: [Haskell-cafe] Porting GHC to OSX86?
Thanks for your response, I'll follow your saga and hopefully learn a bit more about GHC's guts in the process. On 07/05/2006, at 4:05 AM, Reilly Hayes wrote: You'll get a better response to this on the glasgow-haskell-users list. I'm cross-posting my reply. I'm brand new to hacking on GHC, but I've been working on this in my pitifully meagre spare time. The actual expert is Wolfgang Thaller, but he doesn't seem to be around the lists lately. I was able to generate hc files on a 386 linux box (actually on a Parallels virtual machine on my mac, as my linux boxen all run 64 bit linuces).I'll share my findings so far: 1) STABLE does not have the appropriate code in the Mangler to deal with Darwin/86. I've been playing with various versions of HEAD. 2) HEAD has gone through a major revision to the directory structure. The documentation and some of the build processes have not caught up. Simon Marlow sent a helpful e-mail to the ghc users list a few days ago that you should look at. 3) Building the .hc files mostly requires the appropriate settings in mk/build.mk on the Host (linux) machine. I'll include my build.mk below. There is a target in the top level makefile called hc-file-bundle (which needs to be invoked with the parameter ProjectNameShort=ghc in HEAD and Project=ghc in STABLE). This target packages up the .hc files, but does not build them. Some of the .hc files in utils (genapply, genprimopcode, ghc-pkg) don't get built. I just cd to the directories and make them by hand (be sure to use the in-place compiler). A GhcUtilsHcOpts variable in the make structure would be nice (in order to pass -keep-hc-files to ghc when building these on the host). 4) I have been working with Registerised hc files. This may have been a mistake, as registerised code seems to present some unique challenges on Darwin/86. See the items below for a discussion. 5) If I understand correctly (somebody with better knowledge please correct me), there is a register allocation conflict between ghc and relocatable code generated by gcc on the 386 (gcc flag -fPIC). This limits ghc to producing static binaries. The gcc in Xcode builds relocatable code by default and requires -static to build static binaries. I think this conflict is limited to code that goes through the Mangler (registerized code). 6) If I understand correctly, there is code in the RTS that cannot be built using the native code generator. Which suggests that we're stuck with static binaries. There is a ticket to fix this in HEAD. 7) Mac OS X really doesn't like static binaries. In fact, in order to link a static binary, you have to go to opendarwin and download the Csu package to build crt0.o. It's not included in any of the development tools. Apple warns that static binaries are likely to fail to operate in O/S version changes. Curently I'm fighting with the Makefiles to figure out how to get the -static flag stuffed into all of the invocations of gcc. Some of the invocations in rts components don't seem to obey the normal variables used in the makefile structure. I haven't had time to puzzle this out and won't for a few days. mk/build.mk used to generate hc files: GhcLibHcOpts = -O -fasm -keep-hc-files GhcRtsHcOpts = -fasm -keep-hc-files GhcWithInterpreter = NO GhcStage1HcOpts = -O GhcStage2HcOpts = -O -fasm -keep-hc-files SRC_HC_OPTS += -H32m -reilly hayes On May 5, 2006, at 7:34 PM, Scott Weeks wrote: Hi All, Does anyone know if there's been any headway on this? If there's not a port available, where do I go about finding the hc files? Could I compile on a windows or linux x86 box and use the generated hc files to bootstrap? Cheers, Scott On 22/03/2006, at 7:09 AM, Deling Ren wrote: Hi there, Has anyone made any attempt to port GHC to Mac OS X on x86? Wolfgang Thaller’s binary package runs over Rosetta but slow (not surprising). It can not be used to compile a native version either (I got some errors related to machine registers). I tried to do a bootstrap but can't find the .HC files mentioned in the manual. They don't seem to be on the download page of GHC. Any ideas? Thanks. Deling___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe Reilly Hayes [EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Porting GHC to OSX86?
Hi All, Does anyone know if there's been any headway on this? If there's not a port available, where do I go about finding the hc files? Could I compile on a windows or linux x86 box and use the generated hc files to bootstrap? Cheers, Scott On 22/03/2006, at 7:09 AM, Deling Ren wrote: Hi there, Has anyone made any attempt to port GHC to Mac OS X on x86? Wolfgang Thaller’s binary package runs over Rosetta but slow (not surprising). It can not be used to compile a native version either (I got some errors related to machine registers). I tried to do a bootstrap but can't find the .HC files mentioned in the manual. They don't seem to be on the download page of GHC. Any ideas? Thanks. Deling___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Ambiguous types for collection keys
Hello everyone,
I've been banging my head against my desk a bit so I figured it's time
to ask for help :-)
I'm writing an application that persists data to disk. The hard stuff
is pretty much done (binary serialisation, etc...) The big stumbling
block is that I want users to be able to define their own schemas. This
means that the keys for a data store may be Integer, Strings, etc...
I have a BTreeIndex type:
data BTreeIndex a b = Branch { parentBT :: !BlockPtr,
keysBT :: ![a],
kidsBT :: ![BlockPtr] }
| Leaf { parentBT :: !BlockPtr,
valsBT :: !(LeafMap a b),
prevBT :: !PrevLeaf,
nextBT :: !NextLeaf }
type IdxPS = BTreeIndex PackedString BlockPtr
type IdxInt = BTreeIndex Integer BlockPtr
When a user queries I have to read the input from IO and then somehow
cast the key/index type without angering the type checker. If I omit
the following function I get the ominous Ambiguous type variable a...
error. If I use it I get a complaint that the checker was expecting an
Integer rather than a PackedString.
coerceIndex f (Schema _ SInt SPtr _) (r,hdl,o,hdr) = f
(r::IdxInt,hdl,o,hdr)
coerceIndex f (Schema _ SStr SPtr _) (r,hdl,o,hdr) = f
(r::IdxPS,hdl,o,hdr)
Where f is a curried select function (e.g. selectAll, selectByKey,
etc...) waiting for the final tuple containing the index and other
miscellanea that is needed to read the data.
I'm hopelessly lost and I assume that the many brilliant minds on this
list will chuckle, pat me on the head and tell me what I've been doing
wrong.
Thanks for your time guys,
Scott
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Re: [Haskell-cafe] Ambiguous types for collection keys
Well, if you get an ambiguous type variable error, you probably (I think) need to add some type annotations. For example: class Foo a where foo :: a bar :: a - String Evaluating bar foo will result in an error, but bar (foo :: Integer) will work just fine. The problem is that I get an incoming value which is a key of some sort. There's no way of knowing what type that value is supposed to be until I compare it with the schema from the above example. where I _am_ adding type annotations. coerceIndex f (Schema _ SInt SPtr _) (r,hdl,o,hdr) = f (r::IdxInt,hdl,o,hdr) coerceIndex f (Schema _ SStr SPtr _) (r,hdl,o,hdr) = f (r::IdxPS,hdl,o,hdr) When I try to add type annotations I get a complaint from the typechecker that says (In the case of the above example) Expected type: Integer, Inferred Type: PackedString. Is the alternative to write different select methods for each key type (selectInt, selectPS, ...)? God I hope not, that would be a bit scary. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Ambiguous types for collection keys
Or carry an instance in along with a type parameter, using existentials or GADT. Brandon Moore Do you know of an example that would apply to my situation? I think I neglected to state part of my problem. I am storing the root nodes of btree indexes in a heterogeneous list using Typeable. When they come out of the list they need to be unwrapped I think this will clarify my situation because I've been doing a poor job of explaining: import Data.Dynamic data Foo a = FVal a deriving (Show, Typeable) type FooStr = Foo String type FooInt = Foo Integer main = do fooType - getLine fooVal - getLine let foo = toDyn (FVal fooVal) fs= [foo] (f:_) = fs Just dynFoo = fromDynamic f dostuff dynFoo dostuff :: (Show a) = Foo a - IO () dostuff (FVal x) = print x This fails with: Ambiguous type variable `a' in the constraints: `Typeable a' arising from use of `fromDynamic' at /Users/weeksie/workspace/haskell/Main.hs:243:20-30 `Show a' arising from use of `dostuff' at /Users/weeksie/workspace/haskell/Main.hs:247:2-8 Probable fix: add a type signature that fixes these type variable(s) However, changing main: main = do fooType - getLine fooVal - getLine let foo = toDyn (FVal fooVal) fs= [foo] (f:_) = fs Just dynFoo = fromDynamic f if fooType == str then dostuff (dynFoo::FooStr) else dostuff (dynFoo::FooInt) Fails with: Couldn't match `Integer' against `String' Expected type: FooInt Inferred type: FooStr In the expression: dynFoo :: FooInt In the first argument of `dostuff', namely `(dynFoo :: FooInt)' I'm probably going about this in the wrong way. I'd love some advice on how to either do it better or weave some Type Magic to achieve the same effect. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Ambiguous types for collection keys
You are trying to assign two distinct types to dynFoo; that's a no-no.
You need to move the usage of the polymorphic function out of the let
so that the use at each distinct type doesn't get unified.
{-# OPTIONS -fglasgow-exts #-}
import Data.Dynamic
data Foo a = FVal a
deriving (Show, Typeable)
type FooStr = Foo String
type FooInt = Foo Integer
main = do
fooType - getLine
fooVal - getLine
let foo = toDyn (FVal fooVal)
fs= [foo]
(f:_) = fs
if fooType == str
then dostuff (fromDyn f undefined :: Foo String)
else dostuff (fromDyn f undefined :: Foo Int)
dostuff :: (Show a) = Foo a - IO ()
dostuff (FVal x) = print x
BTW, this little example always stuffs a string into the FVal, so
trying to get anything else out will fail.
Thanks for the example it makes a bit of sense now, I really appreciate
you taking the time to help me on this.
Cheers,
Scott
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Re: [Haskell-cafe] does haskell have plist's ?
I just wanted to say thanks for posting that, I have been struggling with a similar problem and I still haven't fully wrapped my head around Typeable and fundeps so that PList code you posted helped immensely. Cheers, Scott On 05/02/2006, at 3:57 AM, J. Garrett Morris wrote: On 2/4/06, raptor [EMAIL PROTECTED] wrote: does Haskell have a property lists. Like Lisp ? any pointer to examples ? Not built in to the language. It's not hard to get the same functionality though - I've attached a module that takes a (not tremendously elegant) approach to the same thing, though. You'll have to store PLists explicitly, though, and this requires GHC. /g -- We have lingered in the chambers of the sea By sea-girls wreathed with seaweed red and brown Till human voices wake us, and we drown. PList.hs___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to use a wiki to annotate GHC Docs? was Re: [Haskell] Re: Making Haskell more open
The public comment/wiki spam problem is easily solved. Use JavaScript to generate a value and put it in a hidden form field. Check for that value server side, if it's there then allow the post otherwise disallow. Most if not all bots don't have JavaScript engines. On 16/11/2005, at 10:15 PM, Neil Mitchell wrote: I don't think restricting editing to registered users is a significant turn off if registration is simple. It really really is a turn off. Sometimes when I spot a mistake, and I'm at a computer where I haven't logged in to hawiki, I don't bother fixing it. No one wants to have yet another account, to fill in their personal details yet again. I appreciate spam is a problem, but turning off unregistered users is a trade off - less content, less spam, less open to people joining - its not a free solution. Thanks Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] How to use a wiki to annotate GHC Docs? was Re: [Haskell] Re: Making Haskell more open
Most if not all bots don't have JavaScript engines. But not all users use JavaScript. I can certainly understand that some users don't have JavaScript but it's the vast minority. The choice is between usability. With captchas you can exclude the disabled and people with poor eyesight (as well as those who can't be bothered trying to figure out what it says). Those that have JavaScript turned off are generally technically proficient because (in most cases) they've made the choice to turn it off. So the choice is still there to post as long as you provide good error messages. So JavaScript is the least intrusive Captchas are the most In between would be a form field that asks a very simple question such as what's this site about? Hint: it's Haskell Cheers, Scott ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] doc/html - wiki - xml
Frankly, the best way to go about writing your doc would be to do it in LaTeX/literate haskell. That way you could compile it to html/pdf/whatever. On 15/11/2005, at 2:40 AM, Bulat Ziganshin wrote: Hello Haskellers, i'm now write documention about Template Haskell in MS Word. when it will be written, i will be glad to publish it in Wiki, so anyone can correct it. and when all be done, it will be great to automatically convert this wiki text to DocBook XML for inserting in GHC documentation can anyone say me about tools/scripts which can be used to do this? or share your ideas - how can i write scripts to do it? -- Best regards, Bulat mailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Information on B-Tree IO implemenations
Thanks Malcolm, that is a great explanation. In this code, in fact we managed to keep the lookup function pure, because the Binary interface allows referentially-transparent I/O (getFAt), which may not be possible in other serialisation libraries. This facility however depends on an invariant that the B-Tree can only be extended - there is no operation to remove nodes or data. That's perfect. The insertion functions clear up the IO part of the equation immensely and since I will need to be able to delete nodes and data it will allow me to implement search/delete myself and cement a bit of this in my head. Cheers, that was a great help. On 07/11/2005, at 11:12 PM, Malcolm Wallace wrote: Scott Weeks [EMAIL PROTECTED] writes: For a project that I'm working on I need to implement a B-Tree or similar disk based data structure for storing large amounts of data. I feel like I'm getting it and then I get hung up on disk IO operations and trying to figure out how they should fit into the mix. Here is a first-cut specification of a B-Tree: data BTree k d = BTree Int [(k,[d])] [BTree k d] where k = key and d = stored data. Obviously this does not actually store the B-Tree on file, it just gives a flavour of the intended structure. In order to store the data on file, we need to introduce an indirection corresponding to a file pointer, on each of the child nodes. data BTree k d = BTree Int [(k,[d])] [FilePtr (BTree k d)] Then you need a serialisation routine to write any one node of the tree out and read it back in. And your tree-traversal routines (lookup, insert, etc) need to be embedded in the IO monad, so they can do the necessary file access. Attached is an implementation of B-Trees (by Colin Runciman), which uses nhc98's Binary class http://haskell.org/nhc98/libs/Binary.html for serialisation. The type BinHandle corresponds to a file handle, and Bin corresponds to a file pointer. In this code, in fact we managed to keep the lookup function pure, because the Binary interface allows referentially-transparent I/O (getFAt), which may not be possible in other serialisation libraries. This facility however depends on an invariant that the B-Tree can only be extended - there is no operation to remove nodes or data. However the insertion routine clearly must use I/O to extend the tree. I hope you can see the pattern of how this I/O works. Note also that the B-Tree structure is stored in BPages, separate from the data values hanging off the tree, which are in DBlocks. Hope this helps, Regards, Malcolm BTree.hs___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Information on B-Tree IO implemenations
Hello all, (I'm resending this because I sent the first one without being a member of the list and I'm assuming it bounced) I'm a newbie and while I grasp some of the basics of FP I have yet to really understand the guts of Haskell. The type system is starting to clear up for me and so are Monads but I have a long way to go. For a project that I'm working on I need to implement a B-Tree or similar disk based data structure for storing large amounts of data. I feel like I'm getting it and then I get hung up on disk IO operations and trying to figure out how they should fit into the mix. I'm not necessarily looking for someone to point me at an implementation (although I wouldn't mind) but if someone could point me in the direction of some material that could shed a light on things I would be much obliged. I've read some Okasaki and found a promising paper called Database Manipulation in Haskell 1.3 by Kevin Hammond and Phil Trinder but while they talk to the data structures themselves they don't quite get around to mentioning how they achieve the IO part of the equation. Thanks, Scotty Weeks ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
