1. 03 May, 2011 1 commit
    • Simon Peyton Jones's avatar
      More hacking on monad-comp · e01036f8
      Simon Peyton Jones authored
      Lots of refactoring. In particular I have now combined
      TansformStmt and GroupStmt into a single constructor TransStmt.
      This gives lots of useful code sharing.
      e01036f8
  2. 02 May, 2011 2 commits
  3. 29 Apr, 2011 1 commit
  4. 28 Apr, 2011 1 commit
  5. 27 Jan, 2011 1 commit
    • simonpj@microsoft.com's avatar
      Refine incomplete-pattern checks (Trac #4905) · a0f6d307
      simonpj@microsoft.com authored
      The changes are:
      
      * New flag -fwarn-incomplete-uni-patterns, which checks for
        incomplete patterns in (a) lambdas, (b) pattern bindings
      
      * New flag is not implied by -W or -Wall (too noisy; and many
        libraries use incomplete pattern bindings)
      
      * Actually do the incomplete-pattern check for pattern bindings
        (previously simply omitted)
      
      * Documentation for new flag
      a0f6d307
  6. 25 Jan, 2011 1 commit
  7. 22 Dec, 2010 1 commit
    • simonpj@microsoft.com's avatar
      Tidy up rebindable syntax for MDo · ba05282d
      simonpj@microsoft.com authored
      For a long time an 'mdo' expression has had a SyntaxTable
      attached to it.  However, we're busy deprecating SyntaxTables
      in favour of rebindable syntax attached to individual Stmts,
      and MDoExpr was totally inconsistent with DoExpr in this
      regard.
      
      This patch tidies it all up.  Now there's no SyntaxTable on
      MDoExpr, and 'modo' is generally handled much more like 'do'.
      
      There is resulting small change in behaviour: now MonadFix is
      required only if you actually *use* recursion in mdo. This
      seems consistent with the implicit dependency analysis that
      is done for mdo.
      
      Still to do:
        * Deal with #4148 (this patch is on the way)
        * Get rid of the last remaining SyntaxTable on HsCmdTop
      ba05282d
  8. 10 Dec, 2010 1 commit
    • simonpj@microsoft.com's avatar
      Fix Trac #4534: renamer bug · 78363495
      simonpj@microsoft.com authored
        
      The renamer wasn't attaching the right used-variables to a
      TransformStmt constructor.
      
      The real modification is in RnExpr; the rest is just
      pretty-printing and white space.
      78363495
  9. 22 Oct, 2010 1 commit
    • simonpj@microsoft.com's avatar
      Add rebindable syntax for if-then-else · 4e0c994e
      simonpj@microsoft.com authored
      There are two main changes
      
       * New LANGUAGE option RebindableSyntax, which implies NoImplicitPrelude
      
       * if-the-else becomes rebindable, with function name "ifThenElse"
         (but case expressions are unaffected)
      
      Thanks to Sam Anklesaria for doing most of the work here
      4e0c994e
  10. 15 Sep, 2010 1 commit
  11. 13 Sep, 2010 1 commit
  12. 13 Jun, 2010 1 commit
  13. 30 Mar, 2010 1 commit
  14. 04 Mar, 2010 2 commits
    • simonpj@microsoft.com's avatar
      Comments only · b4556cac
      simonpj@microsoft.com authored
      b4556cac
    • simonpj@microsoft.com's avatar
      Refactor part of the renamer to fix Trac #3901 · f1cc3eb9
      simonpj@microsoft.com authored
      This one was bigger than I anticipated!  The problem was that were
      were gathering the binders from a pattern before renaming -- but with
      record wild-cards we don't know what variables are bound by C {..}
      until after the renamer has filled in the "..".
      
      So this patch does the following
      
      * Change all the collect-X-Binders functions in HsUtils so that
        they expect to only be called *after* renaming.  That means they
        don't need to return [Located id] but just [id].  Which turned out
        to be a very worthwhile simplification all by itself.
      
      * Refactor the renamer, and in ptic RnExpr.rnStmt, so that it
        doesn't need to use collectLStmtsBinders on pre-renamed Stmts.
      
      * This in turn required me to understand how GroupStmt and
        TransformStmts were renamed.  Quite fiddly. I rewrote most of it;
        result is much shorter.
      
      * In doing so I flattened HsExpr.GroupByClause into its parent
        GroupStmt, with trivial knock-on effects in other files.
      
      Blargh.
      f1cc3eb9
  15. 10 Feb, 2010 1 commit
    • simonpj@microsoft.com's avatar
      Several TH/quasiquote changes · 6f8ff0bb
      simonpj@microsoft.com authored
      a) Added quasi-quote forms for
            declarations
            types
         e.g.   f :: [$qq| ... |]
      
      b) Allow Template Haskell pattern quotes (but not splices)
         e.g.  f x = [p| Int -> $x |]
      
      c) Improve pretty-printing for HsPat to remove superfluous
         parens.  (This isn't TH related really, but it affects
         some of the same code.)
      
      
      A consequence of (a) is that when gathering and grouping declarations
      in RnSource.findSplice, we must expand quasiquotes as we do so.
      Otherwise it's all fairly straightforward.  I did a little bit of
      refactoring in TcSplice.
      
      User-manual changes still to come.
      6f8ff0bb
  16. 20 Jan, 2010 1 commit
    • simonpj@microsoft.com's avatar
      Fix Trac #3813: unused variables in GHCi bindings · 85f969a6
      simonpj@microsoft.com authored
      In a GHCi stmt we don't want to report unused variables, 
      because we don't know the scope of the binding, eg
      
      	Prelude> x <- blah
      
      Fixing this needed a little more info about the context of the stmt,
      thus the new constructor GhciStmt in the HsStmtContext type.
      85f969a6
  17. 26 Nov, 2009 1 commit
  18. 29 Oct, 2009 1 commit
  19. 28 Oct, 2009 1 commit
    • simonpj@microsoft.com's avatar
      Add 'rec' to stmts in a 'do', and deprecate 'mdo' · f04dead9
      simonpj@microsoft.com authored
      The change is this (see Trac #2798).  Instead of writing
      
        mdo { a <- getChar
            ; b <- f c
            ; c <- g b
            ; putChar c
            ; return b }
      
      you would write
      
        do { a <- getChar
           ; rec { b <- f c
                 ; c <- g b }
           ; putChar c
           ; return b }
      
      That is, 
        * 'mdo' is eliminated 
        * 'rec' is added, which groups a bunch of statements
          into a single recursive statement
      
      This 'rec' thing is already present for the arrow notation, so it  
      makes the two more uniform.  Moreover, 'rec' lets you say more
      precisely where the recursion is (if you want to), whereas 'mdo' just
      says "there's recursion here somewhere".  Lastly, all this works with
      rebindable syntax (which mdo does not).
      
      Currently 'mdo' is enabled by -XRecursiveDo.  So we now deprecate this
      flag, with another flag -XDoRec to enable the 'rec' keyword.
      
      Implementation notes:
        * Some changes in Lexer.x
        * All uses of RecStmt now use record syntax
      
      I'm still not really happy with the "rec_ids" and "later_ids" in the
      RecStmt constructor, but I don't dare change it without consulting Ross
      about the consequences for arrow syntax.
      f04dead9
  20. 15 Oct, 2009 1 commit
  21. 23 Jul, 2009 3 commits
  22. 08 Jun, 2009 1 commit
  23. 31 Mar, 2009 1 commit
  24. 30 Oct, 2008 1 commit
    • simonpj@microsoft.com's avatar
      Improve error reporting for non-rigid GADT matches · 259d5ea8
      simonpj@microsoft.com authored
      Following suggestions from users, this patch improves the error message
      when a GADT match needs a rigid type:
      
       tcfail172.hs:19:10:
           GADT pattern match in non-rigid context for `Nil'
      -      Solution: add a type signature
      +      Probable solution: add a type signature for `is_normal'
           In the pattern: Nil
           In the definition of `is_normal': is_normal Nil = True
      
      Now GHC tries to tell you what to give a type signature *for*.
      Thanks to Daniel Gorin and others for the suggestions.
      259d5ea8
  25. 20 Sep, 2008 1 commit
  26. 14 Oct, 2008 1 commit
  27. 11 Aug, 2008 1 commit
  28. 04 Aug, 2008 1 commit
  29. 20 Jul, 2008 1 commit
  30. 13 Jul, 2008 1 commit
  31. 04 Jun, 2008 1 commit
  32. 04 May, 2008 1 commit
  33. 12 Apr, 2008 1 commit
  34. 18 Jan, 2008 1 commit
    • simonpj@microsoft.com's avatar
      Add quasi-quotation, courtesy of Geoffrey Mainland · f3399c44
      simonpj@microsoft.com authored
      This patch adds quasi-quotation, as described in
        "Nice to be Quoted: Quasiquoting for Haskell"
      	(Geoffrey Mainland, Haskell Workshop 2007)
      Implemented by Geoffrey and polished by Simon.
      
      Overview
      ~~~~~~~~
      The syntax for quasiquotation is very similar to the existing
      Template haskell syntax:
      	[$q| stuff |]
      where 'q' is the "quoter".  This syntax differs from the paper, by using
      a '$' rather than ':', to avoid clashing with parallel array comprehensions.
       
      The "quoter" is a value of type Language.Haskell.TH.Quote.QuasiQuoter, which
      contains two functions for quoting expressions and patterns, respectively.
       
           quote = Language.Haskell.TH.Quote.QuasiQuoter quoteExp quotePat
       
           quoteExp :: String -> Language.Haskell.TH.ExpQ
           quotePat :: String -> Language.Haskell.TH.PatQ
      
      TEXT is passed unmodified to the quoter. The context of the
      quasiquotation statement determines which of the two quoters is
      called: if the quasiquotation occurs in an expression context,
      quoteExp is called, and if it occurs in a pattern context, quotePat
      is called.
      
      The result of running the quoter on its arguments is spliced into
      the program using Template Haskell's existing mechanisms for
      splicing in code. Note that although Template Haskell does not
      support pattern brackets, with this patch binding occurrences of
      variables in patterns are supported. Quoters must also obey the same
      stage restrictions as Template Haskell; in particular, in this
      example quote may not be defined in the module where it is used as a
      quasiquoter, but must be imported from another module.
      
      Points to notice
      ~~~~~~~~~~~~~~~~
      * The whole thing is enabled with the flag -XQuasiQuotes
      
      * There is an accompanying patch to the template-haskell library. This
        involves one interface change:
      	currentModule :: Q String
        is replaced by
      	location :: Q Loc
        where Loc is a data type defined in TH.Syntax thus:
            data Loc
              = Loc { loc_filename :: String
      	      , loc_package  :: String
      	      , loc_module   :: String
      	      , loc_start    :: CharPos
      	      , loc_end      :: CharPos }
      
            type CharPos = (Int, Int)	-- Line and character position
       
        So you get a lot more info from 'location' than from 'currentModule'.
        The location you get is the location of the splice.
        
        This works in Template Haskell too of course, and lets a TH program
        generate much better error messages.
      
      * There's also a new module in the template-haskell package called 
        Language.Haskell.TH.Quote, which contains support code for the
        quasi-quoting feature.
      
      * Quasi-quote splices are run *in the renamer* because they can build 
        *patterns* and hence the renamer needs to see the output of running the
        splice.  This involved a bit of rejigging in the renamer, especially
        concerning the reporting of duplicate or shadowed names.
      
        (In fact I found and removed a few calls to checkDupNames in RnSource 
        that are redundant, becuase top-level duplicate decls are handled in
        RnNames.)
      
      
      f3399c44
  35. 17 Jan, 2008 1 commit
    • Isaac Dupree's avatar
      lots of portability changes (#1405) · 206b4dec
      Isaac Dupree authored
      re-recording to avoid new conflicts was too hard, so I just put it
      all in one big patch :-(  (besides, some of the changes depended on
      each other.)  Here are what the component patches were:
      
      Fri Dec 28 11:02:55 EST 2007  Isaac Dupree <id@isaac.cedarswampstudios.org>
        * document BreakArray better
      
      Fri Dec 28 11:39:22 EST 2007  Isaac Dupree <id@isaac.cedarswampstudios.org>
        * properly ifdef BreakArray for GHCI
      
      Fri Jan  4 13:50:41 EST 2008  Isaac Dupree <id@isaac.cedarswampstudios.org>
        * change ifs on __GLASGOW_HASKELL__ to account for... (#1405)
        for it not being defined. I assume it being undefined implies
        a compiler with relatively modern libraries but without most
        unportable glasgow extensions.
      
      Fri Jan  4 14:21:21 EST 2008  Isaac Dupree <id@isaac.cedarswampstudios.org>
        * MyEither-->EitherString to allow Haskell98 instance
      
      Fri Jan  4 16:13:29 EST 2008  Isaac Dupree <id@isaac.cedarswampstudios.org>
        * re-portabilize Pretty, and corresponding changes
      
      Fri Jan  4 17:19:55 EST 2008  Isaac Dupree <id@isaac.cedarswampstudios.org>
        * Augment FastTypes to be much more complete
      
      Fri Jan  4 20:14:19 EST 2008  Isaac Dupree <id@isaac.cedarswampstudios.org>
        * use FastFunctions, cleanup FastString slightly
      
      Fri Jan  4 21:00:22 EST 2008  Isaac Dupree <id@isaac.cedarswampstudios.org>
        * Massive de-"#", mostly Int# --> FastInt (#1405)
      
      Fri Jan  4 21:02:49 EST 2008  Isaac Dupree <id@isaac.cedarswampstudios.org>
        * miscellaneous unnecessary-extension-removal
      
      Sat Jan  5 19:30:13 EST 2008  Isaac Dupree <id@isaac.cedarswampstudios.org>
        * add FastFunctions
      206b4dec
  36. 12 Jan, 2008 1 commit