Be a bit more flexible in terminal identification for do_bold

[ghc-hetmet.git] / compiler / ghci / InteractiveUI.hs

diff --git a/compiler/ghci/InteractiveUI.hs b/compiler/ghci/InteractiveUI.hs
index 9b0bdf9..ec1f4bf 100644 (file)
--- a/compiler/ghci/InteractiveUI.hs
+++ b/compiler/ghci/InteractiveUI.hs
@@ -6,10 +6,14 @@
 -- (c) The GHC Team 2005-2006
 --
 -----------------------------------------------------------------------------
 -- (c) The GHC Team 2005-2006
 --
 -----------------------------------------------------------------------------

-module InteractiveUI ( 
-       interactiveUI,
-       ghciWelcomeMsg
-   ) where
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
+module InteractiveUI ( interactiveUI, ghciWelcomeMsg ) where

 
 #include "HsVersions.h"
 
 
 #include "HsVersions.h"
 

@@ -21,14 +25,17 @@ import Debugger
 import qualified GHC
 import GHC              ( Session, LoadHowMuch(..), Target(..),  TargetId(..),
                           Type, Module, ModuleName, TyThing(..), Phase,
 import qualified GHC
 import GHC              ( Session, LoadHowMuch(..), Target(..),  TargetId(..),
                           Type, Module, ModuleName, TyThing(..), Phase,

-                          BreakIndex, Name, SrcSpan, Resume, SingleStep )
+                          BreakIndex, SrcSpan, Resume, SingleStep )
+import PprTyThing

 import DynFlags
 import Packages
 import PackageConfig
 import UniqFM
 import DynFlags
 import Packages
 import PackageConfig
 import UniqFM

-import PprTyThing
+import HscTypes                ( implicitTyThings )

 import Outputable       hiding (printForUser)
 import Module           -- for ModuleEnv
 import Outputable       hiding (printForUser)
 import Module           -- for ModuleEnv

+import Name
+import SrcLoc

 
 -- Other random utilities
 import Digraph
 
 -- Other random utilities
 import Digraph

@@ -38,13 +45,12 @@ import Config
 import StaticFlags
 import Linker
 import Util
 import StaticFlags
 import Linker
 import Util

+import NameSet
+import Maybes          ( orElse )

 import FastString
 
 #ifndef mingw32_HOST_OS
 import FastString
 
 #ifndef mingw32_HOST_OS

-import System.Posix
-#if __GLASGOW_HASKELL__ > 504
-       hiding (getEnv)
-#endif
+import System.Posix hiding (getEnv)

 #else
 import GHC.ConsoleHandler ( flushConsole )
 import System.Win32      ( setConsoleCP, setConsoleOutputCP )
 #else
 import GHC.ConsoleHandler ( flushConsole )
 import System.Win32      ( setConsoleCP, setConsoleOutputCP )

@@ -70,10 +76,12 @@ import System.Exit  ( exitWith, ExitCode(..) )
 import System.Directory
 import System.IO
 import System.IO.Error as IO
 import System.Directory
 import System.IO
 import System.IO.Error as IO

+import System.IO.Unsafe

 import Data.Char
 import Data.Dynamic
 import Data.Array
 import Control.Monad as Monad
 import Data.Char
 import Data.Dynamic
 import Data.Array
 import Control.Monad as Monad

+import Text.Printf

 
 import Foreign.StablePtr       ( newStablePtr )
 import GHC.Exts                ( unsafeCoerce# )
 
 import Foreign.StablePtr       ( newStablePtr )
 import GHC.Exts                ( unsafeCoerce# )

@@ -85,12 +93,9 @@ import System.Posix.Internals ( setNonBlockingFD )
 
 -----------------------------------------------------------------------------
 
 
 -----------------------------------------------------------------------------
 

-ghciWelcomeMsg =
- "   ___         ___ _\n"++
- "  / _ \\ /\\  /\\/ __(_)\n"++
- " / /_\\// /_/ / /  | |    GHC Interactive, version " ++ cProjectVersion ++ ", for Haskell 98.\n"++
- "/ /_\\\\/ __  / /___| |    http://www.haskell.org/ghc/\n"++
- "\\____/\\/ /_/\\____/|_|    Type :? for help.\n"
+ghciWelcomeMsg :: String
+ghciWelcomeMsg = "GHCi, version " ++ cProjectVersion ++
+                 ": http://www.haskell.org/ghc/  :? for help"

 
 type Command = (String, String -> GHCi Bool, Bool, String -> IO [String])
 cmdName (n,_,_,_) = n
 
 type Command = (String, String -> GHCi Bool, Bool, String -> IO [String])
 cmdName (n,_,_,_) = n

@@ -108,7 +113,8 @@ builtin_commands = [
   ("browse",    keepGoing browseCmd,           False, completeModule),
   ("cd",       keepGoing changeDirectory,      False, completeFilename),
   ("check",    keepGoing checkModule,          False, completeHomeModule),
   ("browse",    keepGoing browseCmd,           False, completeModule),
   ("cd",       keepGoing changeDirectory,      False, completeFilename),
   ("check",    keepGoing checkModule,          False, completeHomeModule),

-  ("continue",  continueCmd,                    False, completeNone),
+  ("continue",  keepGoing continueCmd,          False, completeNone),
+  ("cmd",       keepGoing cmdCmd,               False, completeIdentifier),

   ("ctags",    keepGoing createCTagsFileCmd,   False, completeFilename),
   ("def",      keepGoing defineMacro,          False, completeIdentifier),
   ("delete",    keepGoing deleteCmd,            False, completeNone),
   ("ctags",    keepGoing createCTagsFileCmd,   False, completeFilename),
   ("def",      keepGoing defineMacro,          False, completeIdentifier),
   ("delete",    keepGoing deleteCmd,            False, completeNone),

@@ -131,9 +137,11 @@ builtin_commands = [
   ("set",      keepGoing setCmd,               True,  completeSetOptions),
   ("show",     keepGoing showCmd,              False, completeNone),
   ("sprint",    keepGoing sprintCmd,            False, completeIdentifier),
   ("set",      keepGoing setCmd,               True,  completeSetOptions),
   ("show",     keepGoing showCmd,              False, completeNone),
   ("sprint",    keepGoing sprintCmd,            False, completeIdentifier),

-  ("step",      stepCmd,                        False, completeIdentifier), 
+  ("step",      keepGoing stepCmd,              False, completeIdentifier), 
+  ("steplocal", keepGoing stepLocalCmd,         False, completeIdentifier), 
+  ("stepmodule",keepGoing stepModuleCmd,        False, completeIdentifier), 

   ("type",     keepGoing typeOfExpr,           False, completeIdentifier),
   ("type",     keepGoing typeOfExpr,           False, completeIdentifier),

-  ("trace",     traceCmd,                       False, completeIdentifier), 
+  ("trace",     keepGoing traceCmd,             False, completeIdentifier), 

   ("undef",     keepGoing undefineMacro,       False, completeMacro),
   ("unset",    keepGoing unsetOptions,         True,  completeSetOptions)
   ]
   ("undef",     keepGoing undefineMacro,       False, completeMacro),
   ("unset",    keepGoing unsetOptions,         True,  completeSetOptions)
   ]

@@ -149,31 +157,51 @@ shortHelpText = "use :? for help.\n"
 helpText =
  " Commands available from the prompt:\n" ++
  "\n" ++
 helpText =
  " Commands available from the prompt:\n" ++
  "\n" ++

- "   <stmt>                      evaluate/run <stmt>\n" ++
+ "   <statement>                 evaluate/run <statement>\n" ++

  "   :add <filename> ...         add module(s) to the current target set\n" ++
  "   :add <filename> ...         add module(s) to the current target set\n" ++

- "   :abandon                    at a breakpoint, abandon current computation\n" ++
- "   :break [<mod>] <l> [<col>]  set a breakpoint at the specified location\n" ++
- "   :break <name>               set a breakpoint on the specified function\n" ++

  "   :browse [*]<module>         display the names defined by <module>\n" ++
  "   :cd <dir>                   change directory to <dir>\n" ++
  "   :browse [*]<module>         display the names defined by <module>\n" ++
  "   :cd <dir>                   change directory to <dir>\n" ++

- "   :continue                   resume after a breakpoint\n" ++
+ "   :cmd <expr>                 run the commands returned by <expr>::IO String\n" ++

  "   :ctags [<file>]             create tags file for Vi (default: \"tags\")\n" ++
  "   :def <cmd> <expr>           define a command :<cmd>\n" ++
  "   :ctags [<file>]             create tags file for Vi (default: \"tags\")\n" ++
  "   :def <cmd> <expr>           define a command :<cmd>\n" ++

- "   :delete <number>            delete the specified breakpoint\n" ++
- "   :delete *                   delete all breakpoints\n" ++

  "   :edit <file>                edit file\n" ++
  "   :edit                       edit last module\n" ++
  "   :etags [<file>]             create tags file for Emacs (default: \"TAGS\")\n" ++
  "   :edit <file>                edit file\n" ++
  "   :edit                       edit last module\n" ++
  "   :etags [<file>]             create tags file for Emacs (default: \"TAGS\")\n" ++

--- "   :force <expr>               print <expr>, forcing unevaluated parts\n" ++

  "   :help, :?                   display this list of commands\n" ++
  "   :info [<name> ...]          display information about the given names\n" ++
  "   :kind <type>                show the kind of <type>\n" ++
  "   :load <filename> ...        load module(s) and their dependents\n" ++
  "   :help, :?                   display this list of commands\n" ++
  "   :info [<name> ...]          display information about the given names\n" ++
  "   :kind <type>                show the kind of <type>\n" ++
  "   :load <filename> ...        load module(s) and their dependents\n" ++

- "   :module [+/-] [*]<mod> ...  set the context for expression evaluation\n" ++

  "   :main [<arguments> ...]     run the main function with the given arguments\n" ++
  "   :main [<arguments> ...]     run the main function with the given arguments\n" ++

- "   :print [<name> ...]         prints a value without forcing its computation\n" ++
+ "   :module [+/-] [*]<mod> ...  set the context for expression evaluation\n" ++

  "   :quit                       exit GHCi\n" ++
  "   :reload                     reload the current module set\n" ++
  "   :quit                       exit GHCi\n" ++
  "   :reload                     reload the current module set\n" ++

+ "   :type <expr>                show the type of <expr>\n" ++
+ "   :undef <cmd>                undefine user-defined command :<cmd>\n" ++
+ "   :!<command>                 run the shell command <command>\n" ++
+ "\n" ++
+ " -- Commands for debugging:\n" ++
+ "\n" ++
+ "   :abandon                    at a breakpoint, abandon current computation\n" ++
+ "   :back                       go back in the history (after :trace)\n" ++
+ "   :break [<mod>] <l> [<col>]  set a breakpoint at the specified location\n" ++
+ "   :break <name>               set a breakpoint on the specified function\n" ++
+ "   :continue                   resume after a breakpoint\n" ++
+ "   :delete <number>            delete the specified breakpoint\n" ++
+ "   :delete *                   delete all breakpoints\n" ++
+ "   :force <expr>               print <expr>, forcing unevaluated parts\n" ++
+ "   :forward                    go forward in the history (after :back)\n" ++
+ "   :history [<n>]              show the last <n> items in the history (after :trace)\n" ++
+ "   :print [<name> ...]         prints a value without forcing its computation\n" ++
+ "   :sprint [<name> ...]        simplifed version of :print\n" ++
+ "   :step                       single-step after stopping at a breakpoint\n"++
+ "   :step <expr>                single-step into <expr>\n"++
+ "   :steplocal                  single-step restricted to the current top level decl.\n"++
+ "   :stepmodule                 single-step restricted to the current module\n"++
+ "   :trace                      trace after stopping at a breakpoint\n"++
+ "   :trace <expr>               trace into <expr> (remembers breakpoints for :history)\n"++
+
+ "\n" ++
+ " -- Commands for changing settings:\n" ++

  "\n" ++
  "   :set <option> ...           set options\n" ++
  "   :set args <arg> ...         set the arguments returned by System.getArgs\n" ++
  "\n" ++
  "   :set <option> ...           set options\n" ++
  "   :set args <arg> ...         set the arguments returned by System.getArgs\n" ++

@@ -181,29 +209,24 @@ helpText =
  "   :set prompt <prompt>        set the prompt used in GHCi\n" ++
  "   :set editor <cmd>           set the command used for :edit\n" ++
  "   :set stop <cmd>             set the command to run when a breakpoint is hit\n" ++
  "   :set prompt <prompt>        set the prompt used in GHCi\n" ++
  "   :set editor <cmd>           set the command used for :edit\n" ++
  "   :set stop <cmd>             set the command to run when a breakpoint is hit\n" ++

- "\n" ++
- "   :show breaks                show active breakpoints\n" ++
- "   :show context               show the breakpoint context\n" ++
- "   :show modules               show the currently loaded modules\n" ++
- "   :show bindings              show the current bindings made at the prompt\n" ++
- "\n" ++
- "   :sprint [<name> ...]        simplifed version of :print\n" ++
- "   :step                       single-step after stopping at a breakpoint\n"++
- "   :step <expr>                single-step into <expr>\n"++
- "   :type <expr>                show the type of <expr>\n" ++
- "   :undef <cmd>                undefine user-defined command :<cmd>\n" ++

  "   :unset <option> ...         unset options\n" ++
  "   :unset <option> ...         unset options\n" ++

- "   :!<command>                 run the shell command <command>\n" ++

  "\n" ++
  "\n" ++

- " Options for ':set' and ':unset':\n" ++
+ "  Options for ':set' and ':unset':\n" ++

  "\n" ++
  "    +r            revert top-level expressions after each evaluation\n" ++
  "    +s            print timing/memory stats after each evaluation\n" ++
  "    +t            print type after evaluation\n" ++
  "    -<flags>      most GHC command line flags can also be set here\n" ++
  "                         (eg. -v2, -fglasgow-exts, etc.)\n" ++
  "\n" ++
  "    +r            revert top-level expressions after each evaluation\n" ++
  "    +s            print timing/memory stats after each evaluation\n" ++
  "    +t            print type after evaluation\n" ++
  "    -<flags>      most GHC command line flags can also be set here\n" ++
  "                         (eg. -v2, -fglasgow-exts, etc.)\n" ++

+ "\n" ++
+ " -- Commands for displaying information:\n" ++
+ "\n" ++
+ "   :show bindings              show the current bindings made at the prompt\n" ++
+ "   :show breaks                show the active breakpoints\n" ++
+ "   :show context               show the breakpoint context\n" ++
+ "   :show modules               show the currently loaded modules\n" ++
+ "   :show <setting>             show anything that can be set with :set (e.g. args)\n" ++

  "\n" 
  "\n" 

--- Todo: add help for breakpoint commands here

 
 findEditor = do
   getEnv "EDITOR" 
 
 findEditor = do
   getEnv "EDITOR" 

@@ -229,21 +252,22 @@ interactiveUI session srcs maybe_expr = do
    newStablePtr stdout
    newStablePtr stderr
 
    newStablePtr stdout
    newStablePtr stderr
 

-       -- Initialise buffering for the *interpreted* I/O system
+    -- Initialise buffering for the *interpreted* I/O system

    initInterpBuffering session
 
    when (isNothing maybe_expr) $ do
    initInterpBuffering session
 
    when (isNothing maybe_expr) $ do

-       -- Only for GHCi (not runghc and ghc -e):
-       -- Turn buffering off for the compiled program's stdout/stderr
-       turnOffBuffering
-       -- Turn buffering off for GHCi's stdout
-       hFlush stdout
-       hSetBuffering stdout NoBuffering
-       -- We don't want the cmd line to buffer any input that might be
-       -- intended for the program, so unbuffer stdin.
-       hSetBuffering stdin NoBuffering
-
-       -- initial context is just the Prelude
+        -- Only for GHCi (not runghc and ghc -e):
+
+        -- Turn buffering off for the compiled program's stdout/stderr
+        turnOffBuffering
+        -- Turn buffering off for GHCi's stdout
+        hFlush stdout
+        hSetBuffering stdout NoBuffering
+        -- We don't want the cmd line to buffer any input that might be
+        -- intended for the program, so unbuffer stdin.
+        hSetBuffering stdin NoBuffering
+
+        -- initial context is just the Prelude

    prel_mod <- GHC.findModule session prel_name (Just basePackageId)
    GHC.setContext session [] [prel_mod]
 
    prel_mod <- GHC.findModule session prel_name (Just basePackageId)
    GHC.setContext session [] [prel_mod]
 

@@ -274,7 +298,8 @@ interactiveUI session srcs maybe_expr = do
                    prelude = prel_mod,
                    break_ctr = 0,
                    breaks = [],
                    prelude = prel_mod,
                    break_ctr = 0,
                    breaks = [],

-                   tickarrays = emptyModuleEnv
+                   tickarrays = emptyModuleEnv,
+                   cmdqueue = []

                  }
 
 #ifdef USE_READLINE
                  }
 
 #ifdef USE_READLINE

@@ -334,28 +359,28 @@ runGHCi paths maybe_expr = do
   let show_prompt = verbosity dflags > 0 || is_tty
 
   case maybe_expr of
   let show_prompt = verbosity dflags > 0 || is_tty
 
   case maybe_expr of

-       Nothing -> 
+        Nothing ->

           do
 #if defined(mingw32_HOST_OS)
           do
 #if defined(mingw32_HOST_OS)

-            -- The win32 Console API mutates the first character of 
+            -- The win32 Console API mutates the first character of

             -- type-ahead when reading from it in a non-buffered manner. Work
             -- around this by flushing the input buffer of type-ahead characters,
             -- but only if stdin is available.
             flushed <- io (IO.try (GHC.ConsoleHandler.flushConsole stdin))
             -- type-ahead when reading from it in a non-buffered manner. Work
             -- around this by flushing the input buffer of type-ahead characters,
             -- but only if stdin is available.
             flushed <- io (IO.try (GHC.ConsoleHandler.flushConsole stdin))

-            case flushed of 
-            Left err | isDoesNotExistError err -> return ()
-                     | otherwise -> io (ioError err)
-            Right () -> return ()
+            case flushed of
+             Left err | isDoesNotExistError err -> return ()
+                      | otherwise -> io (ioError err)
+             Right () -> return ()

 #endif
 #endif

-           -- initialise the console if necessary
-           io setUpConsole
+            -- initialise the console if necessary
+            io setUpConsole

 
 

-           -- enter the interactive loop
-           interactiveLoop is_tty show_prompt
-       Just expr -> do
-           -- just evaluate the expression we were given
-           runCommandEval expr
-           return ()
+            -- enter the interactive loop
+            interactiveLoop is_tty show_prompt
+        Just expr -> do
+            -- just evaluate the expression we were given
+            runCommandEval expr
+            return ()

 
   -- and finally, exit
   io $ do when (verbosity dflags > 0) $ putStrLn "Leaving GHCi."
 
   -- and finally, exit
   io $ do when (verbosity dflags > 0) $ putStrLn "Leaving GHCi."

@@ -433,17 +458,9 @@ fileLoop hdl show_prompt = do
        Right l -> 
          case removeSpaces l of
             "" -> fileLoop hdl show_prompt
        Right l -> 
          case removeSpaces l of
             "" -> fileLoop hdl show_prompt

-           l  -> do quit <- runCommand l
+           l  -> do quit <- runCommands l

                      if quit then return () else fileLoop hdl show_prompt
 
                      if quit then return () else fileLoop hdl show_prompt
 

-stringLoop :: [String] -> GHCi Bool{-True: we quit-}
-stringLoop [] = return False
-stringLoop (s:ss) = do
-   case removeSpaces s of
-       "" -> stringLoop ss
-       l  -> do quit <- runCommand l
-                 if quit then return True else stringLoop ss
-

 mkPrompt = do
   session <- getSession
   (toplevs,exports) <- io (GHC.getContext session)
 mkPrompt = do
   session <- getSession
   (toplevs,exports) <- io (GHC.getContext session)

@@ -458,7 +475,7 @@ mkPrompt = do
                    then return (brackets (ppr (GHC.resumeSpan r)) <> space)
                    else do
                         let hist = GHC.resumeHistory r !! (ix-1)
                    then return (brackets (ppr (GHC.resumeSpan r)) <> space)
                    else do
                         let hist = GHC.resumeHistory r !! (ix-1)

-                        span <- io $ GHC.getHistorySpan session hist
+                        span <- io$ GHC.getHistorySpan session hist

                         return (brackets (ppr (negate ix) <> char ':' 
                                           <+> ppr span) <> space)
   let
                         return (brackets (ppr (negate ix) <> char ':' 
                                           <+> ppr span) <> space)
   let

@@ -501,17 +518,31 @@ readlineLoop = do
            "" -> readlineLoop
            l  -> do
                  io (addHistory l)
            "" -> readlineLoop
            l  -> do
                  io (addHistory l)

-                 quit <- runCommand l
+                 quit <- runCommands l

                  if quit then return () else readlineLoop
 #endif
 
                  if quit then return () else readlineLoop
 #endif
 

-runCommand :: String -> GHCi Bool
-runCommand c = ghciHandle handler (doCommand c)
-  where 
-    doCommand (':' : command) = specialCommand command
-    doCommand stmt
-       = do timeIt $ runStmt stmt GHC.RunToCompletion
-            return False
+runCommands :: String -> GHCi Bool
+runCommands cmd = do
+        q <- ghciHandle handler (doCommand cmd)
+        if q then return True else runNext
+  where
+       runNext = do
+          st <- getGHCiState
+          case cmdqueue st of
+            []   -> return False
+            c:cs -> do setGHCiState st{ cmdqueue = cs }
+                       runCommands c
+
+       doCommand (':' : cmd) = specialCommand cmd
+       doCommand stmt        = do timeIt $ runStmt stmt GHC.RunToCompletion
+                                  return False
+
+enqueueCommands :: [String] -> GHCi ()
+enqueueCommands cmds = do
+  st <- getGHCiState
+  setGHCiState st{ cmdqueue = cmds ++ cmdqueue st }
+

 
 -- This version is for the GHC command-line option -e.  The only difference
 -- from runCommand is that it catches the ExitException exception and
 
 -- This version is for the GHC command-line option -e.  The only difference
 -- from runCommand is that it catches the ExitException exception and

@@ -533,62 +564,87 @@ runCommandEval c = ghciHandle handleEval (doCommand c)
 runStmt :: String -> SingleStep -> GHCi Bool
 runStmt stmt step
  | null (filter (not.isSpace) stmt) = return False
 runStmt :: String -> SingleStep -> GHCi Bool
 runStmt stmt step
  | null (filter (not.isSpace) stmt) = return False

+ | ["import", mod] <- words stmt    = keepGoing setContext ('+':mod)

  | otherwise
  = do st <- getGHCiState
       session <- getSession
       result <- io $ withProgName (progname st) $ withArgs (args st) $
                     GHC.runStmt session stmt step
  | otherwise
  = do st <- getGHCiState
       session <- getSession
       result <- io $ withProgName (progname st) $ withArgs (args st) $
                     GHC.runStmt session stmt step

-      afterRunStmt result
-      return False
+      afterRunStmt (const True) result

 
 
 
 

-afterRunStmt :: GHC.RunResult -> GHCi (Maybe (Bool,[Name]))
-afterRunStmt run_result = do
-  mb_result <- switchOnRunResult run_result
-  -- possibly print the type and revert CAFs after evaluating an expression
-  show_types <- isOptionSet ShowType
-  session <- getSession
-  case mb_result of
-    Nothing    -> return ()      
-    Just (is_break,names) -> 
-            when (is_break || show_types) $
-                  mapM_ (showTypeOfName session) names
-  
+--afterRunStmt :: GHC.RunResult -> GHCi Bool
+                                 -- False <=> the statement failed to compile
+afterRunStmt _ (GHC.RunException e) = throw e
+afterRunStmt step_here run_result = do
+  session     <- getSession
+  resumes <- io $ GHC.getResumeContext session
+  case run_result of
+     GHC.RunOk names -> do
+        show_types <- isOptionSet ShowType
+        when show_types $ printTypeOfNames session names
+     GHC.RunBreak _ names mb_info 
+         | isNothing  mb_info || 
+           step_here (GHC.resumeSpan $ head resumes) -> do
+               printForUser $ ptext SLIT("Stopped at") <+> 
+                       ppr (GHC.resumeSpan $ head resumes)
+--               printTypeOfNames session names
+               printTypeAndContentOfNames session names
+               maybe (return ()) runBreakCmd mb_info
+               -- run the command set with ":set stop <cmd>"
+               st <- getGHCiState
+               enqueueCommands [stop st]
+               return ()
+         | otherwise -> io(GHC.resume session GHC.SingleStep) >>= 
+                        afterRunStmt step_here >> return ()
+     _ -> return ()
+

   flushInterpBuffers
   io installSignalHandlers
   b <- isOptionSet RevertCAFs
   io (when b revertCAFs)
 
   flushInterpBuffers
   io installSignalHandlers
   b <- isOptionSet RevertCAFs
   io (when b revertCAFs)
 

-  return mb_result
-
-
-switchOnRunResult :: GHC.RunResult -> GHCi (Maybe (Bool,[Name]))
-switchOnRunResult GHC.RunFailed = return Nothing
-switchOnRunResult (GHC.RunException e) = throw e
-switchOnRunResult (GHC.RunOk names) = return $ Just (False,names)
-switchOnRunResult (GHC.RunBreak threadId names info) = do
-   session <- getSession
-   Just mod_info <- io $ GHC.getModuleInfo session (GHC.breakInfo_module info) 
-   let modBreaks  = GHC.modInfoModBreaks mod_info
-   let ticks      = GHC.modBreaks_locs modBreaks
-
-   -- display information about the breakpoint
-   let location = ticks ! GHC.breakInfo_number info
-   printForUser $ ptext SLIT("Stopped at") <+> ppr location
-
-   -- run the command set with ":set stop <cmd>"
-   st <- getGHCiState
-   runCommand (stop st)
-
-   return (Just (True,names))
-
-
-showTypeOfName :: Session -> Name -> GHCi ()
-showTypeOfName session n
+  return (case run_result of GHC.RunOk _ -> True; _ -> False)
+
+      where printTypeAndContentOfNames session names = do
+              let namesSorted = sortBy compareNames names
+              tythings <- catMaybes `liftM` 
+                              io (mapM (GHC.lookupName session) namesSorted)
+             let ids = [id | AnId id <- tythings]
+              terms <- mapM (io . GHC.obtainTermB session 10 False) ids
+              docs_terms <- mapM (io . showTerm session) terms                                   
+             dflags <- getDynFlags
+             let pefas = dopt Opt_PrintExplicitForalls dflags
+              printForUser $ vcat $ zipWith (\ty cts -> ty <+> equals <+> cts)
+                                            (map (pprTyThing pefas . AnId) ids)
+                                            docs_terms
+
+runBreakCmd :: GHC.BreakInfo -> GHCi ()
+runBreakCmd info = do
+  let mod = GHC.breakInfo_module info
+      nm  = GHC.breakInfo_number info
+  st <- getGHCiState
+  case  [ loc | (i,loc) <- breaks st,
+                breakModule loc == mod, breakTick loc == nm ] of
+        []  -> return ()
+        loc:_ | null cmd  -> return ()
+              | otherwise -> do enqueueCommands [cmd]; return ()
+              where cmd = onBreakCmd loc
+
+printTypeOfNames :: Session -> [Name] -> GHCi ()
+printTypeOfNames session names
+ = mapM_ (printTypeOfName session) $ sortBy compareNames names
+
+compareNames :: Name -> Name -> Ordering
+n1 `compareNames` n2 = compareWith n1 `compare` compareWith n2
+    where compareWith n = (getOccString n, getSrcSpan n)
+
+printTypeOfName :: Session -> Name -> GHCi ()
+printTypeOfName session n

    = do maybe_tything <- io (GHC.lookupName session n)
    = do maybe_tything <- io (GHC.lookupName session n)

-       case maybe_tything of
-         Nothing    -> return ()
-         Just thing -> showTyThing thing
+        case maybe_tything of
+            Nothing    -> return ()
+            Just thing -> printTyThing thing

 
 specialCommand :: String -> GHCi Bool
 specialCommand ('!':str) = shellEscape (dropWhile isSpace str)
 
 specialCommand :: String -> GHCi Bool
 specialCommand ('!':str) = shellEscape (dropWhile isSpace str)

@@ -606,7 +662,7 @@ lookupCommand str = do
   -- look for exact match first, then the first prefix match
   case [ c | c <- cmds, str == cmdName c ] of
      c:_ -> return (Just c)
   -- look for exact match first, then the first prefix match
   case [ c | c <- cmds, str == cmdName c ] of
      c:_ -> return (Just c)

-     [] -> case [ c | c@(s,_,_,_) <- cmds, prefixMatch str s ] of
+     [] -> case [ c | c@(s,_,_,_) <- cmds, str `isPrefixOf` s ] of

                [] -> return Nothing
                c:_ -> return (Just c)
 
                [] -> return Nothing
                c:_ -> return (Just c)
 

@@ -626,6 +682,20 @@ getCurrentBreakSpan = do
                 span <- io $ GHC.getHistorySpan session hist
                 return (Just span)
 
                 span <- io $ GHC.getHistorySpan session hist
                 return (Just span)
 

+getCurrentBreakModule :: GHCi (Maybe Module)
+getCurrentBreakModule = do
+  session <- getSession
+  resumes <- io $ GHC.getResumeContext session
+  case resumes of
+    [] -> return Nothing
+    (r:rs) -> do
+        let ix = GHC.resumeHistoryIx r
+        if ix == 0
+           then return (GHC.breakInfo_module `liftM` GHC.resumeBreakInfo r)
+           else do
+                let hist = GHC.resumeHistory r !! (ix-1)
+                return $ Just $ GHC.getHistoryModule  hist
+

 -----------------------------------------------------------------------------
 -- Commands
 
 -----------------------------------------------------------------------------
 -- Commands
 

@@ -641,30 +711,30 @@ info "" = throwDyn (CmdLineError "syntax: ':i <thing-you-want-info-about>'")
 info s  = do { let names = words s
             ; session <- getSession
             ; dflags <- getDynFlags
 info s  = do { let names = words s
             ; session <- getSession
             ; dflags <- getDynFlags

-            ; let exts = dopt Opt_GlasgowExts dflags
-            ; mapM_ (infoThing exts session) names }
+            ; let pefas = dopt Opt_PrintExplicitForalls dflags
+            ; mapM_ (infoThing pefas session) names }

   where
   where

-    infoThing exts session str = io $ do
-       names <- GHC.parseName session str
-       let filtered = filterOutChildren names
-       mb_stuffs <- mapM (GHC.getInfo session) filtered
+    infoThing pefas session str = io $ do
+       names     <- GHC.parseName session str
+       mb_stuffs <- mapM (GHC.getInfo session) names
+       let filtered = filterOutChildren (\(t,f,i) -> t) (catMaybes mb_stuffs)

        unqual <- GHC.getPrintUnqual session
        putStrLn (showSDocForUser unqual $
                   vcat (intersperse (text "") $
        unqual <- GHC.getPrintUnqual session
        putStrLn (showSDocForUser unqual $
                   vcat (intersperse (text "") $

-                  [ pprInfo exts stuff | Just stuff <-  mb_stuffs ]))
+                        map (pprInfo pefas) filtered))

 
   -- Filter out names whose parent is also there Good
   -- example is '[]', which is both a type and data
   -- constructor in the same type
 
   -- Filter out names whose parent is also there Good
   -- example is '[]', which is both a type and data
   -- constructor in the same type

-filterOutChildren :: [Name] -> [Name]
-filterOutChildren names = filter (not . parent_is_there) names
- where parent_is_there n 
---      | Just p <- GHC.nameParent_maybe n = p `elem` names
--- ToDo!!
-        | otherwise                       = False
-
-pprInfo exts (thing, fixity, insts)
-  =  pprTyThingInContextLoc exts thing 
+filterOutChildren :: (a -> TyThing) -> [a] -> [a]
+filterOutChildren get_thing xs 
+  = [x | x <- xs, not (getName (get_thing x) `elemNameSet` implicits)]
+  where
+    implicits = mkNameSet [getName t | x <- xs, t <- implicitTyThings (get_thing x)]
+
+pprInfo :: PrintExplicitForalls -> (TyThing, Fixity, [GHC.Instance]) -> SDoc
+pprInfo pefas (thing, fixity, insts)
+  =  pprTyThingInContextLoc pefas thing

   $$ show_fixity fixity
   $$ vcat (map GHC.pprInstance insts)
   where
   $$ show_fixity fixity
   $$ vcat (map GHC.pprInstance insts)
   where

@@ -675,8 +745,7 @@ pprInfo exts (thing, fixity, insts)
 runMain :: String -> GHCi ()
 runMain args = do
   let ss = concat $ intersperse "," (map (\ s -> ('"':s)++"\"") (toArgs args))
 runMain :: String -> GHCi ()
 runMain args = do
   let ss = concat $ intersperse "," (map (\ s -> ('"':s)++"\"") (toArgs args))

-  runCommand $ '[': ss ++ "] `System.Environment.withArgs` main"
-  return ()
+  enqueueCommands  ['[': ss ++ "] `System.Environment.withArgs` main"]

 
 addModule :: [FilePath] -> GHCi ()
 addModule files = do
 
 addModule :: [FilePath] -> GHCi ()
 addModule files = do

@@ -702,25 +771,47 @@ changeDirectory dir = do
   io (setCurrentDirectory dir)
 
 editFile :: String -> GHCi ()
   io (setCurrentDirectory dir)
 
 editFile :: String -> GHCi ()

-editFile str
-  | null str  = do
-       -- find the name of the "topmost" file loaded
-     session <- getSession
-     graph0 <- io (GHC.getModuleGraph session)
-     graph1 <- filterM (io . GHC.isLoaded session . GHC.ms_mod_name) graph0
-     let graph2 = flattenSCCs (GHC.topSortModuleGraph True graph1 Nothing)
-     case GHC.ml_hs_file (GHC.ms_location (last graph2)) of
-       Just file -> do_edit file
-       Nothing   -> throwDyn (CmdLineError "unknown file name")
-  | otherwise = do_edit str
-  where
-       do_edit file = do
-          st <- getGHCiState
-          let cmd = editor st
-          when (null cmd) $ 
-               throwDyn (CmdLineError "editor not set, use :set editor")
-          io $ system (cmd ++ ' ':file)
-           return ()
+editFile str =
+  do file <- if null str then chooseEditFile else return str
+     st <- getGHCiState
+     let cmd = editor st
+     when (null cmd) 
+       $ throwDyn (CmdLineError "editor not set, use :set editor")
+     io $ system (cmd ++ ' ':file)
+     return ()
+
+-- The user didn't specify a file so we pick one for them.
+-- Our strategy is to pick the first module that failed to load,
+-- or otherwise the first target.
+--
+-- XXX: Can we figure out what happened if the depndecy analysis fails
+--      (e.g., because the porgrammeer mistyped the name of a module)?
+-- XXX: Can we figure out the location of an error to pass to the editor?
+-- XXX: if we could figure out the list of errors that occured during the
+-- last load/reaload, then we could start the editor focused on the first
+-- of those.
+chooseEditFile :: GHCi String
+chooseEditFile =
+  do session <- getSession
+     let hasFailed x = io $ fmap not $ GHC.isLoaded session $ GHC.ms_mod_name x
+
+     graph <- io (GHC.getModuleGraph session)
+     failed_graph <- filterM hasFailed graph
+     let order g  = flattenSCCs $ GHC.topSortModuleGraph True g Nothing
+         pick xs  = case xs of
+                      x : _ -> GHC.ml_hs_file (GHC.ms_location x)
+                      _     -> Nothing
+
+     case pick (order failed_graph) of
+       Just file -> return file
+       Nothing   -> 
+         do targets <- io (GHC.getTargets session)
+            case msum (map fromTarget targets) of
+              Just file -> return file
+              Nothing   -> throwDyn (CmdLineError "No files to edit.")
+          
+  where fromTarget (GHC.Target (GHC.TargetFile f _) _) = Just f
+        fromTarget _ = Nothing -- when would we get a module target?

 
 defineMacro :: String -> GHCi ()
 defineMacro s = do
 
 defineMacro :: String -> GHCi ()
 defineMacro s = do

@@ -749,7 +840,8 @@ defineMacro s = do
 runMacro :: GHC.HValue{-String -> IO String-} -> String -> GHCi Bool
 runMacro fun s = do
   str <- io ((unsafeCoerce# fun :: String -> IO String) s)
 runMacro :: GHC.HValue{-String -> IO String-} -> String -> GHCi Bool
 runMacro fun s = do
   str <- io ((unsafeCoerce# fun :: String -> IO String) s)

-  stringLoop (lines str)
+  enqueueCommands (lines str)
+  return False

 
 undefineMacro :: String -> GHCi ()
 undefineMacro macro_name = do
 
 undefineMacro :: String -> GHCi ()
 undefineMacro macro_name = do

@@ -764,6 +856,17 @@ undefineMacro macro_name = do
        else do
   io (writeIORef commands (filter ((/= macro_name) . cmdName) cmds))
 
        else do
   io (writeIORef commands (filter ((/= macro_name) . cmdName) cmds))
 

+cmdCmd :: String -> GHCi ()
+cmdCmd str = do
+  let expr = '(' : str ++ ") :: IO String"
+  session <- getSession
+  maybe_hv <- io (GHC.compileExpr session expr)
+  case maybe_hv of
+    Nothing -> return ()
+    Just hv -> do 
+        cmds <- io $ (unsafeCoerce# hv :: IO String)
+        enqueueCommands (lines cmds)
+        return ()

 
 loadModule :: [(FilePath, Maybe Phase)] -> GHCi SuccessFlag
 loadModule fs = timeIt (loadModule' fs)
 
 loadModule :: [(FilePath, Maybe Phase)] -> GHCi SuccessFlag
 loadModule fs = timeIt (loadModule' fs)

@@ -776,6 +879,7 @@ loadModule' files = do
   session <- getSession
 
   -- unload first
   session <- getSession
 
   -- unload first

+  discardActiveBreakPoints

   io (GHC.setTargets session [])
   io (GHC.load session LoadAllTargets)
 
   io (GHC.setTargets session [])
   io (GHC.load session LoadAllTargets)
 

@@ -791,15 +895,13 @@ loadModule' files = do
   -- as a ToDo for now.
 
   io (GHC.setTargets session targets)
   -- as a ToDo for now.
 
   io (GHC.setTargets session targets)

-  ok <- io (GHC.load session LoadAllTargets)
-  afterLoad ok session
-  return ok
+  doLoad session LoadAllTargets

 
 checkModule :: String -> GHCi ()
 checkModule m = do
   let modl = GHC.mkModuleName m
   session <- getSession
 
 checkModule :: String -> GHCi ()
 checkModule m = do
   let modl = GHC.mkModuleName m
   session <- getSession

-  result <- io (GHC.checkModule session modl)
+  result <- io (GHC.checkModule session modl False)

   case result of
     Nothing -> io $ putStrLn "Nothing"
     Just r  -> io $ putStrLn (showSDoc (
   case result of
     Nothing -> io $ putStrLn "Nothing"
     Just r  -> io $ putStrLn (showSDoc (

@@ -814,25 +916,26 @@ checkModule m = do
   afterLoad (successIf (isJust result)) session
 
 reloadModule :: String -> GHCi ()
   afterLoad (successIf (isJust result)) session
 
 reloadModule :: String -> GHCi ()

-reloadModule "" = do
-  io (revertCAFs)              -- always revert CAFs on reload.
-  session <- getSession
-  ok <- io (GHC.load session LoadAllTargets)
-  afterLoad ok session

 reloadModule m = do
 reloadModule m = do

-  io (revertCAFs)              -- always revert CAFs on reload.

   session <- getSession
   session <- getSession

-  ok <- io (GHC.load session (LoadUpTo (GHC.mkModuleName m)))
+  doLoad session $ if null m then LoadAllTargets 
+                             else LoadUpTo (GHC.mkModuleName m)
+  return ()
+
+doLoad session howmuch = do
+  -- turn off breakpoints before we load: we can't turn them off later, because
+  -- the ModBreaks will have gone away.
+  discardActiveBreakPoints
+  ok <- io (GHC.load session howmuch)

   afterLoad ok session
   afterLoad ok session

+  return ok

 
 afterLoad ok session = do
   io (revertCAFs)  -- always revert CAFs on load.
   discardTickArrays
 
 afterLoad ok session = do
   io (revertCAFs)  -- always revert CAFs on load.
   discardTickArrays

-  discardActiveBreakPoints
-  graph <- io (GHC.getModuleGraph session)
-  graph' <- filterM (io . GHC.isLoaded session . GHC.ms_mod_name) graph
-  setContextAfterLoad session graph'
-  modulesLoadedMsg ok (map GHC.ms_mod_name graph')
+  loaded_mods <- getLoadedModules session
+  setContextAfterLoad session loaded_mods
+  modulesLoadedMsg ok (map GHC.ms_mod_name loaded_mods)

 
 setContextAfterLoad session [] = do
   prel_mod <- getPrelude
 
 setContextAfterLoad session [] = do
   prel_mod <- getPrelude

@@ -888,8 +991,10 @@ typeOfExpr str
        maybe_ty <- io (GHC.exprType cms str)
        case maybe_ty of
          Nothing -> return ()
        maybe_ty <- io (GHC.exprType cms str)
        case maybe_ty of
          Nothing -> return ()

-         Just ty -> do ty' <- cleanType ty
-                        printForUser $ text str <> text " :: " <> ppr ty'
+         Just ty -> do dflags <- getDynFlags
+                       let pefas = dopt Opt_PrintExplicitForalls dflags
+                        printForUser $ text str <+> dcolon
+                                       <+> pprTypeForUser pefas ty

 
 kindOfType :: String -> GHCi ()
 kindOfType str 
 
 kindOfType :: String -> GHCi ()
 kindOfType str 

@@ -897,7 +1002,7 @@ kindOfType str
        maybe_ty <- io (GHC.typeKind cms str)
        case maybe_ty of
          Nothing    -> return ()
        maybe_ty <- io (GHC.typeKind cms str)
        case maybe_ty of
          Nothing    -> return ()

-         Just ty    -> printForUser $ text str <> text " :: " <> ppr ty
+         Just ty    -> printForUser $ text str <+> dcolon <+> ppr ty

           
 quit :: String -> GHCi Bool
 quit _ = return True
           
 quit :: String -> GHCi Bool
 quit _ = return True

@@ -935,16 +1040,16 @@ browseModule m exports_only = do
     Just mod_info -> do
         let names
               | exports_only = GHC.modInfoExports mod_info
     Just mod_info -> do
         let names
               | exports_only = GHC.modInfoExports mod_info

-              | otherwise    = fromMaybe [] (GHC.modInfoTopLevelScope mod_info)
+              | otherwise    = GHC.modInfoTopLevelScope mod_info
+                               `orElse` []

 
 

-           filtered = filterOutChildren names
-       
-        things <- io $ mapM (GHC.lookupName s) filtered
+        mb_things <- io $ mapM (GHC.lookupName s) names
+       let filtered_things = filterOutChildren (\t -> t) (catMaybes mb_things)

 
         dflags <- getDynFlags
 
         dflags <- getDynFlags

-       let exts = dopt Opt_GlasgowExts dflags
+       let pefas = dopt Opt_PrintExplicitForalls dflags

        io (putStrLn (showSDocForUser unqual (
        io (putStrLn (showSDocForUser unqual (

-               vcat (map (pprTyThingInContext exts) (catMaybes things))
+               vcat (map (pprTyThingInContext pefas) filtered_things)

           )))
        -- ToDo: modInfoInstances currently throws an exception for
        -- package modules.  When it works, we can do this:
           )))
        -- ToDo: modInfoInstances currently throws an exception for
        -- package modules.  When it works, we can do this:

@@ -1057,6 +1162,19 @@ setEditor cmd = do
   st <- getGHCiState
   setGHCiState st{ editor = cmd }
 
   st <- getGHCiState
   setGHCiState st{ editor = cmd }
 

+setStop str@(c:_) | isDigit c
+  = do let (nm_str,rest) = break (not.isDigit) str
+           nm = read nm_str
+       st <- getGHCiState
+       let old_breaks = breaks st
+       if all ((/= nm) . fst) old_breaks
+              then printForUser (text "Breakpoint" <+> ppr nm <+>
+                                 text "does not exist")
+              else do
+       let new_breaks = map fn old_breaks
+           fn (i,loc) | i == nm   = (i,loc { onBreakCmd = dropWhile isSpace rest })
+                      | otherwise = (i,loc)
+       setGHCiState st{ breaks = new_breaks }

 setStop cmd = do
   st <- getGHCiState
   setGHCiState st{ stop = cmd }
 setStop cmd = do
   st <- getGHCiState
   setGHCiState st{ stop = cmd }

@@ -1074,8 +1192,10 @@ setOptions wds =
    do -- first, deal with the GHCi opts (+s, +t, etc.)
       let (plus_opts, minus_opts)  = partition isPlus wds
       mapM_ setOpt plus_opts
    do -- first, deal with the GHCi opts (+s, +t, etc.)
       let (plus_opts, minus_opts)  = partition isPlus wds
       mapM_ setOpt plus_opts

-

       -- then, dynamic flags
       -- then, dynamic flags

+      newDynFlags minus_opts
+
+newDynFlags minus_opts = do

       dflags <- getDynFlags
       let pkg_flags = packageFlags dflags
       (dflags',leftovers) <- io $ GHC.parseDynamicFlags dflags minus_opts
       dflags <- getDynFlags
       let pkg_flags = packageFlags dflags
       (dflags',leftovers) <- io $ GHC.parseDynamicFlags dflags minus_opts

@@ -1113,10 +1233,11 @@ unsetOptions str
 
        mapM_ unsetOpt plus_opts
  
 
        mapM_ unsetOpt plus_opts
  

-       -- can't do GHC flags for now
-       if (not (null minus_opts))
-         then throwDyn (CmdLineError "can't unset GHC command-line flags")
-         else return ()
+       let no_flag ('-':'f':rest) = return ("-fno-" ++ rest)
+           no_flag f = throwDyn (ProgramError ("don't know how to reverse " ++ f))
+
+       no_flags <- mapM no_flag minus_opts
+       newDynFlags no_flags

 
 isMinus ('-':s) = True
 isMinus _ = False
 
 isMinus ('-':s) = True
 isMinus _ = False

@@ -1148,41 +1269,47 @@ optToStr RevertCAFs = "r"
 -- ---------------------------------------------------------------------------
 -- code for `:show'
 
 -- ---------------------------------------------------------------------------
 -- code for `:show'
 

-showCmd str =
+showCmd str = do
+  st <- getGHCiState

   case words str of
   case words str of

+        ["args"]     -> io $ putStrLn (show (args st))
+        ["prog"]     -> io $ putStrLn (show (progname st))
+        ["prompt"]   -> io $ putStrLn (show (prompt st))
+        ["editor"]   -> io $ putStrLn (show (editor st))
+        ["stop"]     -> io $ putStrLn (show (stop st))

        ["modules" ] -> showModules
        ["bindings"] -> showBindings
        ["linker"]   -> io showLinkerState
        ["modules" ] -> showModules
        ["bindings"] -> showBindings
        ["linker"]   -> io showLinkerState

-        ["breaks"] -> showBkptTable
-        ["context"] -> showContext
-       _ -> throwDyn (CmdLineError "syntax:  :show [modules|bindings|breaks]")
+        ["breaks"]   -> showBkptTable
+        ["context"]  -> showContext
+       _ -> throwDyn (CmdLineError "syntax:  :show [args|prog|prompt|editor|stop|modules|bindings|breaks|context]")

 
 showModules = do
   session <- getSession
 
 showModules = do
   session <- getSession

-  let show_one ms = do m <- io (GHC.showModule session ms)
-                      io (putStrLn m)
+  loaded_mods <- getLoadedModules session
+        -- we want *loaded* modules only, see #1734
+  let show_one ms = do m <- io (GHC.showModule session ms); io (putStrLn m)
+  mapM_ show_one loaded_mods
+
+getLoadedModules :: GHC.Session -> GHCi [GHC.ModSummary]
+getLoadedModules session = do

   graph <- io (GHC.getModuleGraph session)
   graph <- io (GHC.getModuleGraph session)

-  mapM_ show_one graph
+  filterM (io . GHC.isLoaded session . GHC.ms_mod_name) graph

 
 showBindings = do
   s <- getSession
   unqual <- io (GHC.getPrintUnqual s)
   bindings <- io (GHC.getBindings s)
 
 showBindings = do
   s <- getSession
   unqual <- io (GHC.getPrintUnqual s)
   bindings <- io (GHC.getBindings s)

-  mapM_ showTyThing bindings
+  mapM_ printTyThing $ sortBy compareTyThings bindings

   return ()
 
   return ()
 

-showTyThing (AnId id) = do 
-  ty' <- cleanType (GHC.idType id)
-  printForUser $ ppr id <> text " :: " <> ppr ty'
-showTyThing _  = return ()
+compareTyThings :: TyThing -> TyThing -> Ordering
+t1 `compareTyThings` t2 = getName t1 `compareNames` getName t2

 
 

--- if -fglasgow-exts is on we show the foralls, otherwise we don't.
-cleanType :: Type -> GHCi Type
-cleanType ty = do
-  dflags <- getDynFlags
-  if dopt Opt_GlasgowExts dflags 
-       then return ty
-       else return $! GHC.dropForAlls ty
+printTyThing :: TyThing -> GHCi ()
+printTyThing tyth = do dflags <- getDynFlags
+                       let pefas = dopt Opt_PrintExplicitForalls dflags
+                      printForUser (pprTyThing pefas tyth)

 
 showBkptTable :: GHCi ()
 showBkptTable = do
 
 showBkptTable :: GHCi ()
 showBkptTable = do

@@ -1210,10 +1337,11 @@ completeNone w = return []
 completeWord :: String -> Int -> Int -> IO (Maybe (String, [String]))
 completeWord w start end = do
   line <- Readline.getLineBuffer
 completeWord :: String -> Int -> Int -> IO (Maybe (String, [String]))
 completeWord w start end = do
   line <- Readline.getLineBuffer

-  case w of 
+  let line_words = words (dropWhile isSpace line)
+  case w of

      ':':_ | all isSpace (take (start-1) line) -> wrapCompleter completeCmd w
      _other
      ':':_ | all isSpace (take (start-1) line) -> wrapCompleter completeCmd w
      _other

-       | Just c <- is_cmd line -> do
+       | ((':':c) : _) <- line_words -> do

           maybe_cmd <- lookupCommand c
            let (n,w') = selectWord (words' 0 line)
           case maybe_cmd of
           maybe_cmd <- lookupCommand c
            let (n,w') = selectWord (words' 0 line)
           case maybe_cmd of

@@ -1222,6 +1350,8 @@ completeWord w start end = do
             Just (_,_,True,complete) -> let complete' w = do rets <- complete w
                                                               return (map (drop n) rets)
                                          in wrapCompleter complete' w'
             Just (_,_,True,complete) -> let complete' w = do rets <- complete w
                                                               return (map (drop n) rets)
                                          in wrapCompleter complete' w'

+        | ("import" : _) <- line_words ->
+                wrapCompleter completeModule w

        | otherwise     -> do
                --printf "complete %s, start = %d, end = %d\n" w start end
                wrapCompleter completeIdentifier w
        | otherwise     -> do
                --printf "complete %s, start = %d, end = %d\n" w start end
                wrapCompleter completeIdentifier w

@@ -1237,9 +1367,6 @@ completeWord w start end = do
               | offset+length x >= start = (start-offset,take (end-offset) x)
               | otherwise = selectWord xs
 
               | offset+length x >= start = (start-offset,take (end-offset) x)
               | otherwise = selectWord xs
 

-is_cmd line 
- | ((':':w) : _) <- words (dropWhile isSpace line) = Just w
- | otherwise = Nothing

 
 completeCmd w = do
   cmds <- readIORef commands
 
 completeCmd w = do
   cmds <- readIORef commands

@@ -1392,6 +1519,10 @@ wantNameFromInterpretedModule noCanDo str and_then = do
       []    -> return ()
       (n:_) -> do
             let modl = GHC.nameModule n
       []    -> return ()
       (n:_) -> do
             let modl = GHC.nameModule n

+            if not (GHC.isExternalName n)
+               then noCanDo n $ ppr n <>
+                                text " is not defined in an interpreted module"
+               else do

             is_interpreted <- io (GHC.moduleIsInterpreted session modl)
             if not is_interpreted
                then noCanDo n $ text "module " <> ppr modl <>
             is_interpreted <- io (GHC.moduleIsInterpreted session modl)
             if not is_interpreted
                then noCanDo n $ text "module " <> ppr modl <>

@@ -1409,14 +1540,17 @@ setUpConsole = do
        -- similarly for characters we write to the console.
        --
        -- At the moment, GHCi pretends all input is Latin-1.  In the
        -- similarly for characters we write to the console.
        --
        -- At the moment, GHCi pretends all input is Latin-1.  In the

-       -- future we should support UTF-8, but for now we set the code pages
-       -- to Latin-1.
+       -- future we should support UTF-8, but for now we set the code
+       -- pages to Latin-1.  Doing it this way does lead to problems,
+       -- however: see bug #1649.

        --
        -- It seems you have to set the font in the console window to
        -- a Unicode font in order for output to work properly,
        -- otherwise non-ASCII characters are mapped wrongly.  sigh.
        -- (see MSDN for SetConsoleOutputCP()).
        --
        --
        -- It seems you have to set the font in the console window to
        -- a Unicode font in order for output to work properly,
        -- otherwise non-ASCII characters are mapped wrongly.  sigh.
        -- (see MSDN for SetConsoleOutputCP()).
        --

+        -- This call has been known to hang on some machines, see bug #1483
+        --

        setConsoleCP 28591       -- ISO Latin-1
        setConsoleOutputCP 28591 -- ISO Latin-1
 #endif
        setConsoleCP 28591       -- ISO Latin-1
        setConsoleOutputCP 28591 -- ISO Latin-1
 #endif

@@ -1433,26 +1567,57 @@ pprintCommand bind force str = do
   session <- getSession
   io $ pprintClosureCommand session bind force str
 
   session <- getSession
   io $ pprintClosureCommand session bind force str
 

-stepCmd :: String -> GHCi Bool
-stepCmd []         = doContinue GHC.SingleStep
-stepCmd expression = runStmt expression GHC.SingleStep
-
-traceCmd :: String -> GHCi Bool
-traceCmd []         = doContinue GHC.RunAndLogSteps
-traceCmd expression = runStmt expression GHC.RunAndLogSteps
-
-continueCmd :: String -> GHCi Bool
-continueCmd [] = doContinue GHC.RunToCompletion
-continueCmd other = do
-   io $ putStrLn "The continue command accepts no arguments."
-   return False
-
-doContinue :: SingleStep -> GHCi Bool
-doContinue step = do 
+stepCmd :: String -> GHCi ()
+stepCmd []         = doContinue (const True) GHC.SingleStep
+stepCmd expression = do runStmt expression GHC.SingleStep; return ()
+
+stepLocalCmd :: String -> GHCi ()
+stepLocalCmd  [] = do 
+  mb_span <- getCurrentBreakSpan
+  case mb_span of
+    Nothing  -> stepCmd []
+    Just loc -> do
+       Just mod <- getCurrentBreakModule
+       current_toplevel_decl <- enclosingTickSpan mod loc
+       doContinue (`isSubspanOf` current_toplevel_decl) GHC.SingleStep
+
+stepLocalCmd expression = stepCmd expression
+
+stepModuleCmd :: String -> GHCi ()
+stepModuleCmd  [] = do 
+  mb_span <- getCurrentBreakSpan
+  case mb_span of
+    Nothing  -> stepCmd []
+    Just loc -> do
+       Just span <- getCurrentBreakSpan
+       let f some_span = optSrcSpanFileName span == optSrcSpanFileName some_span
+       doContinue f GHC.SingleStep
+
+stepModuleCmd expression = stepCmd expression
+
+-- | Returns the span of the largest tick containing the srcspan given
+enclosingTickSpan :: Module -> SrcSpan -> GHCi SrcSpan
+enclosingTickSpan mod src = do
+  ticks <- getTickArray mod
+  let line = srcSpanStartLine src
+  ASSERT (inRange (bounds ticks) line) do
+  let enclosing_spans = [ span | (_,span) <- ticks ! line
+                               , srcSpanEnd span >= srcSpanEnd src]
+  return . head . sortBy leftmost_largest $ enclosing_spans
+
+traceCmd :: String -> GHCi ()
+traceCmd []         = doContinue (const True) GHC.RunAndLogSteps
+traceCmd expression = do runStmt expression GHC.RunAndLogSteps; return ()
+
+continueCmd :: String -> GHCi ()
+continueCmd = noArgs $ doContinue (const True) GHC.RunToCompletion
+
+-- doContinue :: SingleStep -> GHCi ()
+doContinue pred step = do 

   session <- getSession
   runResult <- io $ GHC.resume session step
   session <- getSession
   runResult <- io $ GHC.resume session step

-  afterRunStmt runResult
-  return False
+  afterRunStmt pred runResult
+  return ()

 
 abandonCmd :: String -> GHCi ()
 abandonCmd = noArgs $ do
 
 abandonCmd :: String -> GHCi ()
 abandonCmd = noArgs $ do

@@ -1479,26 +1644,41 @@ deleteCmd argLine = do
          | otherwise = return ()
 
 historyCmd :: String -> GHCi ()
          | otherwise = return ()
 
 historyCmd :: String -> GHCi ()

-historyCmd = noArgs $ do
-  s <- getSession
-  resumes <- io $ GHC.getResumeContext s
-  case resumes of
-    [] -> io $ putStrLn "Not stopped at a breakpoint"
-    (r:rs) -> do
-      let hist = GHC.resumeHistory r
-      spans <- mapM (io . GHC.getHistorySpan s) hist
-      printForUser (vcat (map ppr spans))
+historyCmd arg
+  | null arg        = history 20
+  | all isDigit arg = history (read arg)
+  | otherwise       = io $ putStrLn "Syntax:  :history [num]"
+  where
+  history num = do
+    s <- getSession
+    resumes <- io $ GHC.getResumeContext s
+    case resumes of
+      [] -> io $ putStrLn "Not stopped at a breakpoint"
+      (r:rs) -> do
+        let hist = GHC.resumeHistory r
+            (took,rest) = splitAt num hist
+        spans <- mapM (io . GHC.getHistorySpan s) took
+        let nums  = map (printf "-%-3d:") [(1::Int)..]
+        let names = map GHC.historyEnclosingDecl took
+        printForUser (vcat(zipWith3 
+                             (\x y z -> x <+> y <+> z) 
+                             (map text nums) 
+                             (map (bold . ppr) names)
+                             (map (parens . ppr) spans)))
+        io $ putStrLn $ if null rest then "<end of history>" else "..."
+
+bold c | do_bold   = text start_bold <> c <> text end_bold
+       | otherwise = c

 
 backCmd :: String -> GHCi ()
 backCmd = noArgs $ do
   s <- getSession
   (names, ix, span) <- io $ GHC.back s
   printForUser $ ptext SLIT("Logged breakpoint at") <+> ppr span
 
 backCmd :: String -> GHCi ()
 backCmd = noArgs $ do
   s <- getSession
   (names, ix, span) <- io $ GHC.back s
   printForUser $ ptext SLIT("Logged breakpoint at") <+> ppr span

-  mapM_ (showTypeOfName s) names
+  printTypeOfNames s names

    -- run the command set with ":set stop <cmd>"
   st <- getGHCiState
    -- run the command set with ":set stop <cmd>"
   st <- getGHCiState

-  runCommand (stop st)
-  return ()
+  enqueueCommands [stop st]

 
 forwardCmd :: String -> GHCi ()
 forwardCmd = noArgs $ do
 
 forwardCmd :: String -> GHCi ()
 forwardCmd = noArgs $ do

@@ -1507,11 +1687,10 @@ forwardCmd = noArgs $ do
   printForUser $ (if (ix == 0)
                     then ptext SLIT("Stopped at")
                     else ptext SLIT("Logged breakpoint at")) <+> ppr span
   printForUser $ (if (ix == 0)
                     then ptext SLIT("Stopped at")
                     else ptext SLIT("Logged breakpoint at")) <+> ppr span

-  mapM_ (showTypeOfName s) names
+  printTypeOfNames s names

    -- run the command set with ":set stop <cmd>"
   st <- getGHCiState
    -- run the command set with ":set stop <cmd>"
   st <- getGHCiState

-  runCommand (stop st)
-  return ()
+  enqueueCommands [stop st]

 
 -- handle the "break" command
 breakCmd :: String -> GHCi ()
 
 -- handle the "break" command
 breakCmd :: String -> GHCi ()

@@ -1535,7 +1714,7 @@ breakSwitch session args@(arg1:rest)
               io $ putStrLn "Perhaps no modules are loaded for debugging?"
    | otherwise = do -- try parsing it as an identifier
         wantNameFromInterpretedModule noCanDo arg1 $ \name -> do
               io $ putStrLn "Perhaps no modules are loaded for debugging?"
    | otherwise = do -- try parsing it as an identifier
         wantNameFromInterpretedModule noCanDo arg1 $ \name -> do

-        let loc = GHC.nameSrcLoc name
+        let loc = GHC.srcSpanStart (GHC.nameSrcSpan name)

         if GHC.isGoodSrcLoc loc
                then findBreakAndSet (GHC.nameModule name) $ 
                          findBreakByCoord (Just (GHC.srcLocFile loc))
         if GHC.isGoodSrcLoc loc
                then findBreakAndSet (GHC.nameModule name) $ 
                          findBreakByCoord (Just (GHC.srcLocFile loc))

@@ -1550,14 +1729,17 @@ breakByModule :: Session -> Module -> [String] -> GHCi ()
 breakByModule session mod args@(arg1:rest)
    | all isDigit arg1 = do  -- looks like a line number
         breakByModuleLine mod (read arg1) rest
 breakByModule session mod args@(arg1:rest)
    | all isDigit arg1 = do  -- looks like a line number
         breakByModuleLine mod (read arg1) rest

-   | otherwise = io $ putStrLn "Invalid arguments to :break"
+breakByModule session mod _
+   = breakSyntax

 
 breakByModuleLine :: Module -> Int -> [String] -> GHCi ()
 breakByModuleLine mod line args
    | [] <- args = findBreakAndSet mod $ findBreakByLine line
    | [col] <- args, all isDigit col =
         findBreakAndSet mod $ findBreakByCoord Nothing (line, read col)
 
 breakByModuleLine :: Module -> Int -> [String] -> GHCi ()
 breakByModuleLine mod line args
    | [] <- args = findBreakAndSet mod $ findBreakByLine line
    | [col] <- args, all isDigit col =
         findBreakAndSet mod $ findBreakByCoord Nothing (line, read col)

-   | otherwise = io $ putStrLn "Invalid arguments to :break"
+   | otherwise = breakSyntax
+
+breakSyntax = throwDyn (CmdLineError "Syntax: :break [<mod>] <line> [<column>]")

 
 findBreakAndSet :: Module -> (TickArray -> Maybe (Int, SrcSpan)) -> GHCi ()
 findBreakAndSet mod lookupTickTree = do 
 
 findBreakAndSet :: Module -> (TickArray -> Maybe (Int, SrcSpan)) -> GHCi ()
 findBreakAndSet mod lookupTickTree = do 

@@ -1575,6 +1757,7 @@ findBreakAndSet mod lookupTickTree = do
                              { breakModule = mod
                              , breakLoc = span
                              , breakTick = tick
                              { breakModule = mod
                              , breakLoc = span
                              , breakTick = tick

+                             , onBreakCmd = ""

                              }
                printForUser $
                   text "Breakpoint " <> ppr nm <>
                              }
                printForUser $
                   text "Breakpoint " <> ppr nm <>

@@ -1595,9 +1778,9 @@ findBreakByLine :: Int -> TickArray -> Maybe (BreakIndex,SrcSpan)
 findBreakByLine line arr
   | not (inRange (bounds arr) line) = Nothing
   | otherwise =
 findBreakByLine line arr
   | not (inRange (bounds arr) line) = Nothing
   | otherwise =

-    listToMaybe (sortBy leftmost_largest  complete)   `mplus`
-    listToMaybe (sortBy leftmost_smallest incomplete) `mplus`
-    listToMaybe (sortBy rightmost ticks)
+    listToMaybe (sortBy (leftmost_largest `on` snd)  complete)   `mplus`
+    listToMaybe (sortBy (leftmost_smallest `on` snd) incomplete) `mplus`
+    listToMaybe (sortBy (rightmost `on` snd) ticks)

   where 
         ticks = arr ! line
 
   where 
         ticks = arr ! line
 

@@ -1612,7 +1795,8 @@ findBreakByCoord :: Maybe FastString -> (Int,Int) -> TickArray
 findBreakByCoord mb_file (line, col) arr
   | not (inRange (bounds arr) line) = Nothing
   | otherwise =
 findBreakByCoord mb_file (line, col) arr
   | not (inRange (bounds arr) line) = Nothing
   | otherwise =

-    listToMaybe (sortBy rightmost contains)
+    listToMaybe (sortBy (rightmost `on` snd) contains ++
+                 sortBy (leftmost_smallest `on` snd) after_here)

   where 
         ticks = arr ! line
 
   where 
         ticks = arr ! line
 

@@ -1624,26 +1808,32 @@ findBreakByCoord mb_file (line, col) arr
                  | Just f <- mb_file = GHC.srcSpanFile span == f
                  | otherwise         = True
 
                  | Just f <- mb_file = GHC.srcSpanFile span == f
                  | otherwise         = True
 

-
-leftmost_smallest  (_,a) (_,b) = a `compare` b
-leftmost_largest   (_,a) (_,b) = (GHC.srcSpanStart a `compare` GHC.srcSpanStart b)
-                                `thenCmp`
-                                 (GHC.srcSpanEnd b `compare` GHC.srcSpanEnd a)
-rightmost (_,a) (_,b) = b `compare` a
-
-spans :: SrcSpan -> (Int,Int) -> Bool
-spans span (l,c) = GHC.srcSpanStart span <= loc && loc <= GHC.srcSpanEnd span
-   where loc = GHC.mkSrcLoc (GHC.srcSpanFile span) l c
-
-start_bold = BS.pack "\ESC[1m"
-end_bold   = BS.pack "\ESC[0m"
+        after_here = [ tick | tick@(nm,span) <- ticks,
+                              GHC.srcSpanStartLine span == line,
+                              GHC.srcSpanStartCol span >= col ]
+
+-- For now, use ANSI bold on terminals that we know support it.
+-- Otherwise, we add a line of carets under the active expression instead.
+-- In particular, on Windows and when running the testsuite (which sets
+-- TERM to vt100 for other reasons) we get carets.
+-- We really ought to use a proper termcap/terminfo library.
+do_bold :: Bool
+do_bold = (`isPrefixOf` unsafePerformIO mTerm) `any` ["xterm", "linux"]
+    where mTerm = System.Environment.getEnv "TERM"
+                  `Exception.catch` \e -> return "TERM not set"
+
+start_bold :: String
+start_bold = "\ESC[1m"
+end_bold :: String
+end_bold   = "\ESC[0m"

 
 listCmd :: String -> GHCi ()
 listCmd "" = do
    mb_span <- getCurrentBreakSpan
    case mb_span of
       Nothing  -> printForUser $ text "not stopped at a breakpoint; nothing to list"
 
 listCmd :: String -> GHCi ()
 listCmd "" = do
    mb_span <- getCurrentBreakSpan
    case mb_span of
       Nothing  -> printForUser $ text "not stopped at a breakpoint; nothing to list"

-      Just span -> io $ listAround span True
+      Just span | GHC.isGoodSrcSpan span -> io $ listAround span True
+                | otherwise              -> printForUser $ text "unable to list source for" <+> ppr span

 listCmd str = list2 (words str)
 
 list2 [arg] | all isDigit arg = do
 listCmd str = list2 (words str)
 
 list2 [arg] | all isDigit arg = do

@@ -1657,7 +1847,7 @@ list2 [arg1,arg2] | looksLikeModuleName arg1, all isDigit arg2 = do
         listModuleLine mod (read arg2)
 list2 [arg] = do
         wantNameFromInterpretedModule noCanDo arg $ \name -> do
         listModuleLine mod (read arg2)
 list2 [arg] = do
         wantNameFromInterpretedModule noCanDo arg $ \name -> do

-        let loc = GHC.nameSrcLoc name
+        let loc = GHC.srcSpanStart (GHC.nameSrcSpan name)

         if GHC.isGoodSrcLoc loc
                then do
                   tickArray <- getTickArray (GHC.nameModule name)
         if GHC.isGoodSrcLoc loc
                then do
                   tickArray <- getTickArray (GHC.nameModule name)

@@ -1701,10 +1891,10 @@ listAround span do_highlight = do
           line_nos = [ fst_line .. ]
 
           highlighted | do_highlight = zipWith highlight line_nos these_lines
           line_nos = [ fst_line .. ]
 
           highlighted | do_highlight = zipWith highlight line_nos these_lines

-                      | otherwise   = these_lines
+                      | otherwise    = [\p -> BS.concat[p,l] | l <- these_lines]

 
           bs_line_nos = [ BS.pack (show l ++ "  ") | l <- line_nos ]
 
           bs_line_nos = [ BS.pack (show l ++ "  ") | l <- line_nos ]

-          prefixed = zipWith BS.append bs_line_nos highlighted
+          prefixed = zipWith ($) highlighted bs_line_nos

       --
       BS.putStrLn (BS.join (BS.pack "\n") prefixed)
   where
       --
       BS.putStrLn (BS.join (BS.pack "\n") prefixed)
   where

@@ -1718,19 +1908,37 @@ listAround span do_highlight = do
                    | otherwise  = 1
         pad_after = 1
 
                    | otherwise  = 1
         pad_after = 1
 

-        highlight no line
+        highlight | do_bold   = highlight_bold
+                  | otherwise = highlight_carets
+
+        highlight_bold no line prefix

           | no == line1 && no == line2
           = let (a,r) = BS.splitAt col1 line
                 (b,c) = BS.splitAt (col2-col1) r
             in
           | no == line1 && no == line2
           = let (a,r) = BS.splitAt col1 line
                 (b,c) = BS.splitAt (col2-col1) r
             in

-            BS.concat [a,start_bold,b,end_bold,c]
+            BS.concat [prefix, a,BS.pack start_bold,b,BS.pack end_bold,c]

           | no == line1
           = let (a,b) = BS.splitAt col1 line in
           | no == line1
           = let (a,b) = BS.splitAt col1 line in

-            BS.concat [a, start_bold, b]
+            BS.concat [prefix, a, BS.pack start_bold, b]

           | no == line2
           = let (a,b) = BS.splitAt col2 line in
           | no == line2
           = let (a,b) = BS.splitAt col2 line in

-            BS.concat [a, end_bold, b]
-          | otherwise   = line
+            BS.concat [prefix, a, BS.pack end_bold, b]
+          | otherwise   = BS.concat [prefix, line]
+
+        highlight_carets no line prefix
+          | no == line1 && no == line2
+          = BS.concat [prefix, line, nl, indent, BS.replicate col1 ' ',
+                                         BS.replicate (col2-col1) '^']
+          | no == line1
+          = BS.concat [indent, BS.replicate (col1 - 2) ' ', BS.pack "vv", nl, 
+                                         prefix, line]
+          | no == line2
+          = BS.concat [prefix, line, nl, indent, BS.replicate col2 ' ',
+                                         BS.pack "^^"]
+          | otherwise   = BS.concat [prefix, line]
+         where
+           indent = BS.pack ("  " ++ replicate (length (show no)) ' ')
+           nl = BS.singleton '\n'

 
 -- --------------------------------------------------------------------------
 -- Tick arrays
 
 -- --------------------------------------------------------------------------
 -- Tick arrays

@@ -1758,7 +1966,7 @@ mkTickArray ticks
         [ (line, (nm,span)) | (nm,span) <- ticks,
                               line <- srcSpanLines span ]
     where
         [ (line, (nm,span)) | (nm,span) <- ticks,
                               line <- srcSpanLines span ]
     where

-        max_line = maximum (map GHC.srcSpanEndLine (map snd ticks))
+        max_line = foldr max 0 (map GHC.srcSpanEndLine (map snd ticks))

         srcSpanLines span = [ GHC.srcSpanStartLine span .. 
                               GHC.srcSpanEndLine span ]
 
         srcSpanLines span = [ GHC.srcSpanStartLine span .. 
                               GHC.srcSpanEndLine span ]