RE: Revival: PROPOSAL: Literate haskell and module file names
Dear Merijn, Do you even need a separate extension or filename convention for this? Can't you just call it lhs and expand the definition thereof to include markdown? (I suggested something similar before, but objections were raised that having too good and too broad an unlitter might lead to the bit-rot of the flag to employ external unlitters. I didn't quite understand that objection, but didn't pursue it) Regards, Philip Van: Glasgow-haskell-users glasgow-haskell-users-boun...@haskell.org namens Merijn Verstraaten mer...@inconsistent.nl Verzonden: zaterdag 16 augustus 2014 00:40 Aan: haskell-pr...@haskell.org; glasgow-haskell-users@haskell.org Onderwerp: Revival: PROPOSAL: Literate haskell and module file names Ola! I raised this proposal earlier this year and got to busy to follow up, this week I was suddenly reminded and decided to reraise this. To summarise the discussion up until this point: There was no real opposition to the general idea, the only real objection to the original proposal was that “Foo.lhs.md” and “Foo.md.lhs” would collide with the naming scheme used by JHC on case insensitive filesystems. Alternative proposal raised during the discussion: Foo+md.lhs, Foo.lhs+md” and “Foo.md+lhs”. According to MS documentation and testing the + should not be an issue on windows, the + doesn’t collide with any other haskell compiler (at least, not any I’m aware off) and since the report doesn’t specify any module name resolution mechanism, it does not conflict with the report either. My personal preferences goes to either “.lhs+md” or “.md+lhs”, since GHC currently tries every alternative in turn, I propose to just extend this list to look for any file whose extension is “.lhs+*” or “.*+lhs”. Are there any objections to this? If not, I’m just going to produce a patch + ticket as there were no real objections to the proposal last time. Cheers, Merijn On 16 Mar 2014, at 05:56 , Merijn Verstraaten mer...@inconsistent.nl wrote: Ola! I didn't know what the most appropriate venue for this proposal was so I crossposted to haskell-prime and glasgow-haskell-users, if this isn't the right venue I welcome advice where to take this proposal. Currently the report does not specify the mapping between filenames and module names (this is an issue in itself, it essentially makes writing haskell code that's interoperable between compilers impossible, as you can't know what directory layout each compiler expects). I believe that a minimal specification *should* go into the report (hence, haskell-prime). However, this is a separate issue from this proposal, so please start a new thread rather than sidetracking this one :) The report only mentions that by convention .hs extensions imply normal haskell and .lhs literate haskell (Section 10.4). In the absence of guidance from the report GHC's convention of mapping module Foo.Bar.Baz to Foo/Bar/Baz.hs or Foo/Bar/Baz.lhs seems the only sort of standard that exists. In general this standard is nice enough, but the mapping of literate haskell is a bit inconvenient, it leaves it completelyl ambiguous what the non-haskell content of said file is, which is annoying for tool authors. Pandoc has adopted the policy of checking for further file extensions for literate haskell source, e.g. Foo.rst.lhs and Foo.md.lhs. Here .rst.lhs gets interpreted as being reStructured Text with literate haskell and .md.lhs is Markdown with literate haskell. Unfortunately GHC currently maps filenames like this to the module names Foo.rst and Foo.md, breaking anything that wants to import the module Foo. I would like to propose allowing an optional extra extension in the pandoc style for literate haskell files, mapping Foo.rst.lhs to module name Foo. This is a backwards compatible change as there is no way for Foo.rst.lhs to be a valid module in the current GHC convention. Foo.rst.lhs would map to module name Foo.rst but module name Foo.rst maps to filename Foo/rst.hs which is not a valid haskell module anyway as the rst is lowercase and module names have to start with an uppercase letter. Pros: - Tool authors can more easily determine non-haskell content of literate haskell files - Currently valid module names will not break - Report doesn't specify behaviour, so GHC can do whatever it likes Cons: - Someone has to implement it - ?? Discussion: 4 weeks Cheers, Merijn ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
RE: GhcPlugin-writing and finding things
Dear Andrew,
Thanks for your suggestion. I had considered it earlier and decided against it
for the extra dependencies. Maybe I was too picky there. I will give it another
go. Could there possibly be a subset of hermit that plugin-writers could depend
on, but that have fewer dependencies? I find it hard to explain to people why
they require things like ansi-terminal if they want to use my
parser-combinators.
I still think this isn't an unreasonable use case to take on board for future
GHC API design, though. Also, the thing with findImportedModule still scares me.
Regards,
Philip
-Original Message-
From: xicheko...@gmail.com [mailto:xicheko...@gmail.com] On Behalf Of
Andrew Farmer
Sent: woensdag 23 juli 2014 19:22
To: Holzenspies, P.K.F. (EWI)
Cc: glasgow-haskell-users@haskell.org
Subject: Re: GhcPlugin-writing and finding things
Have you considered using HERMIT for this? I think this is a rough
approximation of what you are trying to do (using HERMIT):
import HERMIT.Plugin
import HERMIT.Dictionary
plugin = hermitPlugin $ \ opts - firstPhase $ run $ tryR $ innermostR
$ promoteBindR compileFooBindR
compileFooBindR :: RewriteH CoreBind
compileFooBindR = prefixFailMsg compileFooBindR failed: $ do
NonRec b rhs - idR -- only match on non-recursive bindings
tcFoo - findTyConT Foo -- can be fully qualified name if target
code doesn't import directly
guardMsg (varType b `containsTyConAnywhere` tyFoo) does not contain
Foo -- abort if binder doesn't contain Foo in type
return $ NonRec b $ {- magicCompileFunction -} rhs
The goal of HERMIT is to make writing these plugins easier. For
instance, if you give a fully qualified name to findTyConT (or the
other find functions), and HERMIT can't find the name in scope in the
target module, it'll look in the package database for the appropriate
interface and load it.
You can even run your compilation functions interactively and view
their output in a REPL. To do so, change your plugin to:
plugin = hermitPlugin $ firstPhase . interactive exts
exts :: Externals
exts = [ external compile-foo (promoteBindR compileFooBindR) [
compiles bindings involving Foo ] ]
{- compileFooBindR as before -}
Then you can navigate around your AST and use the compile-foo
command to test out your compilation.
If you want to try, I'd highly recommend using the latest from github,
rather than what is on hackage:
https://github.com/ku-fpg/hermit
Here are a few examples of larger HERMIT plugins:
https://github.com/xich/hermit-syb/blob/master/hermit-
syb/HERMIT/Optimization/SYB.hs#L28
https://github.com/conal/lambda-
ccc/blob/master/src/LambdaCCC/Reify.hs#L866
Let me know if you have questions!
Andrew
On Wed, Jul 23, 2014 at 11:06 AM, p.k.f.holzensp...@utwente.nl wrote:
Dear GHC-ers,
I'm working on a plugin for GHC that should help compile the library
with which this plugin is to ship. What this plugin does is traverse the
CoreProgram(s) to find things of types defined in my library and
optimizes them. I have worked out how to find things, but I was
wondering whether the API could be improved for plugin-writers.
For the sake of argument, I have the following:
- module Foo: library for users to import, containing functions, ADTs
etc
- module Foo.Plugin: GhcPlugin that compiles out all uses of things
in Foo
module Foo where
data Foo x = Foo x
runFoo :: Foo x - x
runFoo (Foo x) = x
This example is trivial and I imagine GHC will have no trouble
eliminating most cases of this, but imagine more complex stuff. Now, if
I want to traverse the CoreProgram in my plugin, I need to find
occurrences of these, so somewhere there's stuff like:
pass tcFoo _ _ (NonRec b expr)
| varType b `containsTyConAnywhere` tcFoo
= {- clever stuff to compile out Foo -}
My problem is getting tcFoo in this example. Below is how I do it
now. Maybe I'm being thick, or maybe there's just no simpler way. This
is my 'plugin' function in Foo.Plugin:
plugin = Plugin $ \opts todo - do
hsc - getHscEnv
dfs - getDynFlags
fr - liftIO $ findImportedModule hsc (mkModuleName Foo) Nothing
mod - case fr of
Found ml m - return m
_ - panic Failed to (unambiguously) find 'Foo' (using
findImportedModule)
onc - getOrigNameCache
let nms = lookupWithDefaultModuleEnv nms (panic No names defined
for module 'Foo') mod
find_ d occ fnd nm
= maybe
(fail $ Failed to find ++ d ++ ' ++ nm ++ ')
fnd
(lookupOccEnv nms $ occ nm)
tcFind = find_ TyCon mkTcOcc lookupTyCon
dcFind = find_ DataCon mkDataOcc lookupDataCon
idFind = find_ Id mkVarOcc lookupId
tcFoo- tcFind Foo
dcFoo- dcFind Foo
idRunFoo - idFind runFoo
return $ CoreDoPluginPass Foo optimisation (pass tcFoo dcFoo
idRunFoo) : todo
I have the following questions:
1) Is this a/the right way to
GhcPlugin-writing and finding things
Dear GHC-ers,
I'm working on a plugin for GHC that should help compile the library with which
this plugin is to ship. What this plugin does is traverse the CoreProgram(s) to
find things of types defined in my library and optimizes them. I have worked
out how to find things, but I was wondering whether the API could be improved
for plugin-writers.
For the sake of argument, I have the following:
- module Foo: library for users to import, containing functions, ADTs etc
- module Foo.Plugin: GhcPlugin that compiles out all uses of things in Foo
module Foo where
data Foo x = Foo x
runFoo :: Foo x - x
runFoo (Foo x) = x
This example is trivial and I imagine GHC will have no trouble eliminating most
cases of this, but imagine more complex stuff. Now, if I want to traverse the
CoreProgram in my plugin, I need to find occurrences of these, so somewhere
there's stuff like:
pass tcFoo _ _ (NonRec b expr)
| varType b `containsTyConAnywhere` tcFoo
= {- clever stuff to compile out Foo -}
My problem is getting tcFoo in this example. Below is how I do it now. Maybe
I'm being thick, or maybe there's just no simpler way. This is my 'plugin'
function in Foo.Plugin:
plugin = Plugin $ \opts todo - do
hsc - getHscEnv
dfs - getDynFlags
fr - liftIO $ findImportedModule hsc (mkModuleName Foo) Nothing
mod - case fr of
Found ml m - return m
_ - panic Failed to (unambiguously) find 'Foo' (using
findImportedModule)
onc - getOrigNameCache
let nms = lookupWithDefaultModuleEnv nms (panic No names defined for module
'Foo') mod
find_ d occ fnd nm
= maybe
(fail $ Failed to find ++ d ++ ' ++ nm ++ ')
fnd
(lookupOccEnv nms $ occ nm)
tcFind = find_ TyCon mkTcOcc lookupTyCon
dcFind = find_ DataCon mkDataOcc lookupDataCon
idFind = find_ Id mkVarOcc lookupId
tcFoo- tcFind Foo
dcFoo- dcFind Foo
idRunFoo - idFind runFoo
return $ CoreDoPluginPass Foo optimisation (pass tcFoo dcFoo idRunFoo) :
todo
I have the following questions:
1) Is this a/the right way to find those things in the plugin?
2) There seems to be a lot to gain with quasi-quoting a la Template Haskell
for people writing plugins to go with a library that they wrote. Can such QQ be
done? Has it been considered?
3) Is findImportedModule the right function to find my starting point to
begin with?
4) What is the 'Maybe FastString' argument in findImportedModule for? I've
been trying to put in the FSs of PackageIDs, but they make the lookup fail.
This (dumb) example really made me nervous:
fr - liftIO $ findImportedModule hsc (mkModuleName Foo) Nothing
mod - case fr of
Found ml m - do
fr' - liftIO $ findImportedModule hsc (moduleName m) (packageIdFS $
packageId m)
Here, fr' should always be a Found ml' m' such that ml == ml' and m == m',
but... it consistently results in NotFound{} for me. Also, I find this
especially round-about. Shouldn't Paths_Foo.hs (the Cabal-generated file) maybe
contain variables for every module in the package? In my case it would thus
contain some modFoo :: Module
Comments and suggestions more than welcome!
Regards,
Philip
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RE: Desugaring do-notation to Applicative
I thought the whole point of Applicative (at least, reading Connor’s paper) was to restore some function-application-style to the whole effects-thing, i.e. it was the very point *not* to resort to binds or do-notation. That being said, I’m all for something that will promote the use of the name “pure” over “return”. +1 for the Opt-In Ph. From: Glasgow-haskell-users [mailto:glasgow-haskell-users-boun...@haskell.org] On Behalf Of Iavor Diatchki do x1 - e1 -- The following part is `Applicative` (x2,x3) - do x2 - e2 x1 x3 - e3 pure (x2,x3) f x1 x2 x3 ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
RE: Question about correct GHC-API use for type checking (or zonking, or tidying)
Well, my tcLocalBinds seems to have a different type then yours (this is from
my copy of 7.6.3 and it's the same in the HEAD that I just synced):
tcLocalBinds :: HsLocalBinds Name - TcM thing - TcM (HsLocalBinds TcId, thing)
If I want to get a GblEnv out, I can use getGblEnv, but doing this:
mkId :: Maybe FreeVars - LHsExpr Name - Name - TcM Id
mkId fvs expr@(L l _) nm = do
((binds', gbl_env),lie) - captureConstraints $ tcLocalBinds binds getGblEnv
setGblEnv gbl_env (tcLookupId nm)
where
binds= HsValBinds $ ValBindsOut [(NonRecursive, unitBag fixbnd)] []
the_bind = mkTopFunBind (L l nm) [mkMatch [] expr emptyLocalBinds]
fixbnd = L l $ maybe the_bind (\vs - the_bind { bind_fvs = vs }) fvs
fails on the tcLookupId with a GHC internal error complaining that my name is
not in scope during type checking, but it passed the renamer.
Ph.
From: Simon Peyton-Jones [mailto:simo...@microsoft.com]
Sent: dinsdag 10 september 2013 14:19
To: Holzenspies, P.K.F. (EWI)
Cc: glasgow-haskell-users@haskell.org
Subject: RE: Question about correct GHC-API use for type checking (or zonking,
or tidying)
What goes wrong if you follow my suggestion below?
tcLocalBinds takes a set of bindings, such as x=e
and returns a GblEnv whose type envt is extended with a binding for x with its
generalised type.
This type wil indeed be closed, unless the current environment (in which
tcLocalBinds runs) has bindings with open types. Which in your case it probably
doesn't.
I feel that I am not being helpful but I'm not sure how to help more.
S
From: Philip K.F. Hölzenspies [mailto:p.k.f.holzensp...@utwente.nl]
Sent: 04 September 2013 21:25
To: Simon Peyton-Jones
Cc: glasgow-haskell-users@haskell.orgmailto:glasgow-haskell-users@haskell.org
Subject: Re: Question about correct GHC-API use for type checking (or zonking,
or tidying)
Ah, this is good to know. What I really would like is a function:
mkId :: Name - LHsExpr Name - TcM Id
where that Id is something I can store in my own monad (IA). The meaning of
this, is indeed let name = expression as a top-level binding. The
behaviour should actually be the same as that statement at the ghci-prompt. My
IA monad implements liftTcM as something that invokes a TcM-monad, i.e.
liftTcM :: TcM b - IA b
liftTcM thing_inside = do
hsc_env - getSession
stored_ids - getStoredIds :: IA [Id]-- this is the list of all Ids
made through mkId mentioned above
ioMsgMaybe . initTcPrintErrors hsc_env iNTERACTIVE $
setInteractiveContext hsc_env (hsc_IC hsc_env) $
tcExtendGlobalValEnv stored_ids $ -- or tcExtendIdEnv??
thing_inside
In the example you give below, I'm curious which thing_inside you give to
tcLocalBinds to get you the correct global environment. Also, if I do what you
suggest, i.e.
poly_id - setGblEnv gbl_env (tcLookupId the_id_name)
is that poly_id self contained, in the sense that I can put it in a new
instantiation as shown above?
Regards,
Philip
[cid:image001.jpg@01CEAEDB.407DA510]
Simon Peyton-Jonesmailto:simo...@microsoft.com
September 4, 2013 6:00 PM
The id you are getting is a monomorphic id, with a type like a-a, not the
polymorphic forall a. a-a. You don't want to go round arbitrarily creating a
new Id with the same unique but a different type. I have no idea what would
happen then.
It's hard for me to understand just what you code is trying to do. I think you
are making bindig
it = some expr
and then you want the type of it. Maybe something like
(binds', gbl_env) - tcLocalBinds (..your bindin..)
poly_id - setGblEnv gbl_env (tcLooupId the_id_name)
But I'm not totally sure.
S
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Re: Question about correct GHC-API use for type checking (or zonking, or tidying)
I feel so unbelievably ignorant now. I thought with all the IORefs in the type
checking process that zonking did this in these refs. Somehow I started
thinking that some of these remained in SDocs, not thinking showSDoc is pure
and results in a String, which holds no IORefs.
Does this mean that for the idType to come out correctly I should also zonk
(AND BIND) the Id-value I return?
Ph.
Sent from Samsung Mobile
Original message
From: Simon Peyton-Jones simo...@microsoft.com
Date: 30/08/2013 18:25 (GMT+01:00)
To: Holzenspies, P.K.F. (EWI)
p.k.f.holzensp...@utwente.nl,glasgow-haskell-users@haskell.org
Subject: RE: Question about correct GHC-API use for type checking (or zonking,
or tidying)
Haskell is a *functional* language. Consider
say $ pre-zonk: ++ pp all_expr_ty
zonkTcType all_expr_ty
say $ post-zonk: ++ pp all_expr_ty
pp is a pure function; it is given the same input both times, so of course it
produces the same output.
If you collect the result of zonkTcType you might have better luck, thus:
say $ pre-zonk: ++ pp all_expr_ty
zonked_expr_ty - zonkTcType all_expr_ty
say $ post-zonk: ++ pp zonked_expr_ty
Zonking walks over a type, returning a new type in which unification variables
are replaced by the types they unified to.
Hope this helps
Simon
| -Original Message-
| From: Glasgow-haskell-users [mailto:glasgow-haskell-users-
| boun...@haskell.org] On Behalf Of p.k.f.holzensp...@utwente.nl
| Sent: 29 August 2013 14:42
| To: glasgow-haskell-users@haskell.org
| Subject: Question about correct GHC-API use for type checking (or
| zonking, or tidying)
|
| Dear GHC-ers,
|
| I'm working on building an interactive environment around the
| composition of expressions. Users can type in (i.e. give strings of)
| expressions and can then use these expressions to produce other
| expressions. I'm close to having a working GHC-API binding for this. The
| resulting types, however, still contain some things I don't quite
| understand. Any help would be appreciated.
|
| Below, I've included the function exprFromString which should parse,
| rename and typecheck strings to Id-things and give their type (although,
| ideally, the idType of said Id-thing should be the same as the type
| returned). This function lives in the IA (InterActive) monad; a monad
| that is a GhcMonad and can lift monadic computations in TcM into itself
| using liftTcM (which uses the initTcPrintErrors and
| setInteractiveContext functions similarly to TcRnDriver.tcRnExpr).
|
| Near the end of the function, debugging output is produced. This output
| confuses me slightly. Here is the output for the three inputs map (+1)
| [1..10], 5 and \\x - x:
|
|
| map (+1) [1..10]
| pre-zonk: forall b. (GHC.Enum.Enum b_i, GHC.Num.Num b_i) = [b_i]
| post-zonk: forall b. (GHC.Enum.Enum b_i, GHC.Num.Num b_i) = [b_i]
| idType:[b_c]
| tidied:forall b. (GHC.Enum.Enum b_i, GHC.Num.Num b_i) = [b_i]
| 5
| pre-zonk: forall a. GHC.Num.Num a_d = t_c
| post-zonk: forall a. GHC.Num.Num a_d = t_c
| idType:a_b
| tidied:forall a. GHC.Num.Num a_d = t_c
| \x - x
| pre-zonk: forall t. t_e
| post-zonk: forall t. t_e
| idType:forall t. t - t
| tidied:forall t. t_e
|
|
| The zonking and tidying part of the type-checking process are still a
| bit unclear to me and I suspect the problems arise there. It looks to me
| that the type variables in the quantifications are different ones from
| those in the pi/rho-types. I had expected the types to only contain the
| variables over which they are quantified, so e.g. in the map-example, I
| had expected forall b . (GHC.Enum.Enum b, GHC.Num.Num b) = [b]
|
| Can anyone explain what I'm missing?
|
| Regards,
| Philip
|
|
|
|
|
| exprFromString :: String - IA (Id,Type)
| exprFromString str = do
| dfs - getDynFlags
| let pp = showSDoc dfs . ppr
| pst - mkPState dfs buf $ newRealSrcLoc
|
| {- Parse -}
| (loc,rdr_expr) - case unP parseStmt pst of
| PFailed span err - throwOneError (mkPlainErrMsg dfs span err)
| POk pst' (Just (L l (ExprStmt rdr_expr _ _ _))) - do
| logWarningsReportErrors (getMessages pst')
| return (l,rdr_expr)
| POk pst' thing - throw $ maybe EmptyParse (const
| NonExpressionParse) thing
| liftTcM $ do
| fresh_it - freshName loc str
|
| {- Rename -}
| (rn_expr, fvs) - checkNoErrs $ rnLExpr rdr_expr
|
| {- Typecheck -}
| let binds = mkBinds fresh_it rn_expr fvs
|
| (((_bnds,((_tc_expr,res_ty),id)),untch),lie) - captureConstraints .
| captureUntouchables $
| tcLocalBinds binds ((,) $ tcInferRho rn_expr * tcLookupId
| fresh_it)
| ((qtvs, dicts, _bool, _evbinds), lie_top) - captureConstraints $
| simplifyInfer True False [(fresh_it, res_ty)] (untch,lie)
|
| let all_expr_ty = mkForAllTys qtvs (mkPiTypes dicts res_ty)
| say str
| say $ pre-zonk: ++ pp all_expr_ty
| zonkTcType all_expr_ty
| say $ post-zonk:
Question about correct GHC-API use for type checking (or zonking, or tidying)
Dear GHC-ers,
I'm working on building an interactive environment around the composition of
expressions. Users can type in (i.e. give strings of) expressions and can then
use these expressions to produce other expressions. I'm close to having a
working GHC-API binding for this. The resulting types, however, still contain
some things I don't quite understand. Any help would be appreciated.
Below, I've included the function exprFromString which should parse, rename and
typecheck strings to Id-things and give their type (although, ideally, the
idType of said Id-thing should be the same as the type returned). This function
lives in the IA (InterActive) monad; a monad that is a GhcMonad and can lift
monadic computations in TcM into itself using liftTcM (which uses the
initTcPrintErrors and setInteractiveContext functions similarly to
TcRnDriver.tcRnExpr).
Near the end of the function, debugging output is produced. This output
confuses me slightly. Here is the output for the three inputs map (+1)
[1..10], 5 and \\x - x:
map (+1) [1..10]
pre-zonk: forall b. (GHC.Enum.Enum b_i, GHC.Num.Num b_i) = [b_i]
post-zonk: forall b. (GHC.Enum.Enum b_i, GHC.Num.Num b_i) = [b_i]
idType:[b_c]
tidied:forall b. (GHC.Enum.Enum b_i, GHC.Num.Num b_i) = [b_i]
5
pre-zonk: forall a. GHC.Num.Num a_d = t_c
post-zonk: forall a. GHC.Num.Num a_d = t_c
idType:a_b
tidied:forall a. GHC.Num.Num a_d = t_c
\x - x
pre-zonk: forall t. t_e
post-zonk: forall t. t_e
idType:forall t. t - t
tidied:forall t. t_e
The zonking and tidying part of the type-checking process are still a bit
unclear to me and I suspect the problems arise there. It looks to me that the
type variables in the quantifications are different ones from those in the
pi/rho-types. I had expected the types to only contain the variables over which
they are quantified, so e.g. in the map-example, I had expected forall b .
(GHC.Enum.Enum b, GHC.Num.Num b) = [b]
Can anyone explain what I'm missing?
Regards,
Philip
exprFromString :: String - IA (Id,Type)
exprFromString str = do
dfs - getDynFlags
let pp = showSDoc dfs . ppr
pst - mkPState dfs buf $ newRealSrcLoc
{- Parse -}
(loc,rdr_expr) - case unP parseStmt pst of
PFailed span err - throwOneError (mkPlainErrMsg dfs span err)
POk pst' (Just (L l (ExprStmt rdr_expr _ _ _))) - do
logWarningsReportErrors (getMessages pst')
return (l,rdr_expr)
POk pst' thing - throw $ maybe EmptyParse (const NonExpressionParse) thing
liftTcM $ do
fresh_it - freshName loc str
{- Rename -}
(rn_expr, fvs) - checkNoErrs $ rnLExpr rdr_expr
{- Typecheck -}
let binds = mkBinds fresh_it rn_expr fvs
(((_bnds,((_tc_expr,res_ty),id)),untch),lie) - captureConstraints .
captureUntouchables $
tcLocalBinds binds ((,) $ tcInferRho rn_expr * tcLookupId fresh_it)
((qtvs, dicts, _bool, _evbinds), lie_top) - captureConstraints $
simplifyInfer True False [(fresh_it, res_ty)] (untch,lie)
let all_expr_ty = mkForAllTys qtvs (mkPiTypes dicts res_ty)
say str
say $ pre-zonk: ++ pp all_expr_ty
zonkTcType all_expr_ty
say $ post-zonk: ++ pp all_expr_ty
say $ idType: ++ pp (idType id)
say $ tidied: ++ pp (tidyTopType all_expr_ty)
return (id,all_expr_ty)
where
say = liftIO . putStrLn
buf = stringToStringBuffer str
freshName loc str = (\u - mkInternalName u name loc) $ newUnique
where
name = mkOccNameFS varName $ fsLit $ it ++ show (lineOf loc)
isVarChar c = isAlphaNum c || c == '_' || c == '\''
lineOf (RealSrcSpan s) = srcSpanStartLine s
lineOf _ = -1
mkBinds :: Name - LHsExpr Name - FreeVars - HsLocalBinds Name
mkBinds nm e@(L l _) fvs = HsValBinds $ ValBindsOut [(NonRecursive, unitBag
the_bind)] []
where
the_bind = L l (mkTopFunBind (L l nm) [mkMatch [] e emptyLocalBinds]) {
bind_fvs = fvs }
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RE: How to fix DatatypeContexts?
I've also been experiencing this a lot in class instances, such as:
class Foo f where
foo :: a - f a
data Bar f a = Foo f = Bar {bar :: f a}
instance Foo (Bar f) where
foo a = Bar (foo a)
Is there any way to avoid repeating the Foo f constraint in the Bar f
instance?
Dear Harry, et al,
The problem here is that GADT-constructors simply carry the appropriate
dictionaries. When you *produce* an element of a GADT where the constructor
requires a dictionary, you must provide it there. In this case, for a variable
f, you don't have a dictionary, so you could read the constraint and instance
head as if you give me a Foo-dictionary for f, then I will wrap it in a Bar.
Another way of looking at it is that the type Bar f only 'exists' for 'f's
that are 'Foo's. If you don't know whether a particular 'f' is a 'Foo', you
don't know whether Bar f exists.
In short, I think that there is no such way.
Regards,
Philip
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RE: Re-entrant TcRnIf
Dear Thomas,
Thanks for your reply. If all else fails, this could be the way to go, but if
at all possible, I would like to get rid of the file-idea ;)
Maybe it helps if I make things slightly more concrete. Like I said, I'm
building an interactive user interface. In this interface, users manipulate
terms. There is a bootstrapping problem here; how do they get terms to begin
with? The answer (quite unsatisfactory at the moment): They type them in. For
the sake of the argument, lets say users give these terms names of type UIName.
Part of the UI's state is a Map UIName (LHsExpr Id) which can be manipulated
with, e.g. this function:
addExpr :: UIName - String - UI (Maybe ErrorMessage)
which parses its String argument, akin to how exprType works. The problem, now,
is that if I simply restart the TcRnMonad, I'm worried uniques in one
expression may not be unique in the entire map of expressions. Also, I will be
looking for ways to combine these expression, e.g.
mkApplication :: UIName - UIName - UIName - UI ()
mkApplication new func arg = do
m - gets exprMap
f - maybe (fail ...) return (lookup func m)
a - maybe (fail ...) return (lookup arg m)
let n = L (combineLocs f a) (HsApp f a)
checkType n
modify (\s - s { exprMap = insert new n m })
Again, it seems that restarting the TcRnMonad for everything breaks stuff. Then
again, it probably doesn't help that the AST (f and a in the function above)
contain IORefs with type-state. I was thinking that if that is problematic, I
would always lower the type of 'n' from LHsExpr Id to LHsExpr Name such
that all type information is reconstructed, but it is quite vital that the
renaming is preserved (i.e. I can't go all the way down to LHsExpr RdrName).
Thoughts?
Regards,
Philip
-Original Message-
From: Thomas Schilling [mailto:nomin...@googlemail.com]
Sent: dinsdag 11 juni 2013 13:46
To: Holzenspies, P.K.F. (EWI)
Cc: glasgow-haskell-users@haskell.org
Subject: Re: Re-entrant TcRnIf
There are quite a lot of dependencies between different parts of the AST.
The renamer takes the whole parser output and then discovers its dependencies.
After that you can split things into smaller units based on this dependency
graph.
The renamer and type checker do not necessarily need to be interleaved. Every
Haskell file is de-facto split apart after each top-level TH splice.
If I understand you correctly you want to build some IDE functionality that
only recompiles the parts that changed. You can do that currently (crudely) by
splitting the file into three parts based on the dependency graph that the
renamer discovered:
1. Everything upstream of the focused definition, i.e., everything that does
not depend on the focused definition.
2. The focused definition and everything that is in its recursive group.
3. Everything downstream of the focused, i.e., everything that directly or
indirectly depends on the focused definition.
You can put each part into a separate file and only recompile part 2.
Of course you also need to detect when new (renamer) dependencies are formed as
that will change the split between parts 1, 2, and 3.
Let me know if you need more details on this approach.
/ Thomas
On 11 June 2013 11:55, p.k.f.holzensp...@utwente.nl wrote:
Dear GHC-ers,
The current API *seems* to assume that all different stages of the compiler
pipeline are always passed successively (with the exception of the
interleaving of the renamer and the type checker for the sake of Template
Haskell), in other words, it is assumed all parsing has been done once we
start renaming and that when we desugar the AST, we can through out all type
checker state. I'm working on an interactive environment (different in many
ways from ghci), in which I would like to incrementally parse a statement,
rename it and type check it, after which I may chose to wash, rinse and
repeat.
This is somewhat problematic in the renamer (at least; this is how far I have
come), at the very least with regards to the unique source and the provenance
of things. What I'm hoping to do is to generalize the monads in the GHC API
to some class, along these lines:
class Generalizes m n where
glift :: n a - m a
class (GhcMonad m, Generalizes m TcRnIf, Generalizes m CoreM, ...) =
GHCAPI m
What such a monad needs is to be able to evaluate some function in (for
example) the renamer monad, extract the part of the renamer state that needs
to persist and store that for whenever another renamer function is evaluated.
One such thing would be the supply of unique names.
I tried simply carrying over everything in the Env, except the env_top
(HscEnv), but this broke things. Upon inspection of the TcGblEnv and
TcLclEnv, this seems logical, considering they are dependent on the HscEnv
(at least in terms of tcg_type_env_var, but there may be other dependencies
I've not spotted). The thing that seems to bite me is the assumption that
Re-entrant TcRnIf
Dear GHC-ers, The current API *seems* to assume that all different stages of the compiler pipeline are always passed successively (with the exception of the interleaving of the renamer and the type checker for the sake of Template Haskell), in other words, it is assumed all parsing has been done once we start renaming and that when we desugar the AST, we can through out all type checker state. I'm working on an interactive environment (different in many ways from ghci), in which I would like to incrementally parse a statement, rename it and type check it, after which I may chose to wash, rinse and repeat. This is somewhat problematic in the renamer (at least; this is how far I have come), at the very least with regards to the unique source and the provenance of things. What I'm hoping to do is to generalize the monads in the GHC API to some class, along these lines: class Generalizes m n where glift :: n a - m a class (GhcMonad m, Generalizes m TcRnIf, Generalizes m CoreM, ...) = GHCAPI m What such a monad needs is to be able to evaluate some function in (for example) the renamer monad, extract the part of the renamer state that needs to persist and store that for whenever another renamer function is evaluated. One such thing would be the supply of unique names. I tried simply carrying over everything in the Env, except the env_top (HscEnv), but this broke things. Upon inspection of the TcGblEnv and TcLclEnv, this seems logical, considering they are dependent on the HscEnv (at least in terms of tcg_type_env_var, but there may be other dependencies I've not spotted). The thing that seems to bite me is the assumption that the top-level environment is assumed to be fixed [1]. In my scenario, this assumption does not hold. Concretely: 1) Do ways exist to carry over the part of the TcRnMonad state that is required to restart the renamer / type checker / etc later on? 2) If not, what parts of the Env, TcGblEnv and TcLclEnv should I copy over to the new state, assuming the HscEnv changed between consecutive runs? 3) Is there a particular reason why the front-end (of the front-end) is defined in an overloaded monad (GhcMonad) and the later bits all take concrete monads (TcRnIf etc.)? Regards, Philip [1] http://hackage.haskell.org/trac/ghc/wiki/Commentary/Compiler/TcRnMonad ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
RE: GHC 7.8 release?
+1 Ph. -Original Message- From: glasgow-haskell-users-boun...@haskell.org [mailto:glasgow-haskell- users-boun...@haskell.org] On Behalf Of Richard Eisenberg Sent: donderdag 7 februari 2013 15:01 To: Geoffrey Mainland Cc: parallel-hask...@googlegroups.com; glasgow-haskell-users@haskell.org; ghc-d...@haskell.org Subject: Re: GHC 7.8 release? Geoff's reasoning seems quite sound. +1 for February release. On Feb 7, 2013, at 3:50 AM, Geoffrey Mainland mainl...@apeiron.net wrote: In practice the versions of GHC that are widely used are those that are included in the platform. Maybe we should coordinate with their next release? They are targeting a May 6 release, and the release process is starting March 4, so it sounds like the original GHC release plan (February release) would be a good fit for the platform as it would allow library writers to catch up and ensure that STABLE was tested enough for inclusion in the platform. It would be a shame to miss the platform release. Geoff On 02/07/2013 08:25 AM, Simon Peyton-Jones wrote: Dear GHC users, * * *Carter*: Will this RTS update make it into ghc 7.8 update thats coming up in the next monthish? *Andreas*: We are almost there - we are now trying to sort out a problem on mac os x. It would be helpful to know if there is a cutoff date for getting things into 7.8. Simon, Ian, and I have just been discussing 7.8, and would be interested in what you guys think. At ICFP we speculated that we'd make a release of GHC soon after Christmas to embody tons of stuff that has been included since 7.6, specifically: * major improvements in DPH (vectorisation avoidance, new vectoriser) * type holes * rebindable list syntax * major changes to the type inference engine * type level natural numbers * overlapping type families * the new code generator * support for vector (SSE/AVX) instructions Whenever it comes it would definitely be great to include Andreas friends' work: * Scheduler changes to the RTS to improve latency The original major reason for proposing a post-Xmas release was to get DPH in a working state out into the wild. However, making a proper release imposes costs on everyone else. Library authors have to scurry around to make their libraries work, etc. Some of the new stuff hasn't been in HEAD for that long, and hence has not been very thoroughly tested. (But of course making a release unleashes a huge wave of testing that doesn't happen otherwise.) So another alternative is to leave it all as HEAD, and wait another few months before making a release. You can still use all the new stuff by compiling HEAD, or grabbing a snapshot distribution. And it makes it hard for the Haskell platform if GHC moves too fast. Many people are still on 7.4. There seem to be pros and cons each way. I don't have a strong opinion. If you have a view, let us know. Simon ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
