GHC.Runtime.Context

Documentation

data InteractiveContext

Interactive context, recording information about the state of the context in which statements are executed in a GHCi session.

Constructors

InteractiveContext

Fields

• ic_dflags :: DynFlags

  The DynFlags used to evaluate interactive expressions and statements.

• ic_mod_index :: Int

  Each GHCi stmt or declaration brings some new things into scope. We give them names like interactive:Ghci9.T, where the ic_index is the '9'. The ic_mod_index is incremented whenever we add something to ic_tythings See Note [The interactive package]

• ic_imports :: [InteractiveImport]

  The GHCi top-level scope (icReaderEnv) is extended with these imports

  This field is only stored here so that the client can retrieve it with GHC.getContext. GHC itself doesn't use it, but does reset it to empty sometimes (such as before a GHC.load). The context is set with GHC.setContext.

• ic_tythings :: [TyThing]

  TyThings defined by the user, in reverse order of definition (ie most recent at the front). Also used in GHC.Tc.Module.runTcInteractive to fill the type checker environment. See Note [ic_tythings]

• ic_gre_cache :: IcGlobalRdrEnv

  Essentially the cached GlobalRdrEnv.

  The GlobalRdrEnv contains everything in scope at the command line, both imported and everything in ic_tythings, with the correct shadowing.

  The IcGlobalRdrEnv contains extra data to allow efficient recalculation when the set of imports change. See Note [icReaderEnv recalculation]

• ic_instances :: (InstEnv, [FamInst])

  All instances and family instances created during this session. These are grabbed en masse after each update to be sure that proper overlapping is retained. That is, rather than re-check the overlapping each time we update the context, we just take the results from the instance code that already does that.

• ic_fix_env :: FixityEnv

  Fixities declared in let statements

• ic_default :: Maybe [Type]

  The current default types, set by a 'default' declaration

• ic_resume :: [Resume]

  The stack of breakpoint contexts

• ic_monad :: Name

  The monad that GHCi is executing in

• ic_int_print :: Name

  The function that is used for printing results of expressions in ghci and -e mode.

• ic_cwd :: Maybe FilePath

  virtual CWD of the program

• ic_plugins :: !Plugins

  Cache of loaded plugins. We store them here to avoid having to load them every time we switch to the interactive context.

data InteractiveImport

Constructors

IIDecl (ImportDecl GhcPs)

Bring the exports of a particular module (filtered by an import decl) into scope

IIModule ModuleName

Bring into scope the entire top-level envt of of this module, including the things imported into it.

Instances

Outputable InteractiveImport

Defined in GHC.Runtime.Context

Methods

ppr :: InteractiveImport -> SDoc

emptyInteractiveContext :: DynFlags -> InteractiveContext

Constructs an empty InteractiveContext.

extendInteractiveContext :: InteractiveContext -> [TyThing] -> InstEnv -> [FamInst] -> Maybe [Type] -> FixityEnv -> InteractiveContext

extendInteractiveContext is called with new TyThings recently defined to update the InteractiveContext to include them. By putting new things first, unqualified use will pick the most recently defined thing with a given name, while still keeping the old names in scope in their qualified form (Ghci1.foo).

extendInteractiveContextWithIds :: InteractiveContext -> [Id] -> InteractiveContext

setInteractivePrintName :: InteractiveContext -> Name -> InteractiveContext

substInteractiveContext :: InteractiveContext -> Subst -> InteractiveContext

replaceImportEnv :: IcGlobalRdrEnv -> GlobalRdrEnv -> IcGlobalRdrEnv

icReaderEnv :: InteractiveContext -> GlobalRdrEnv

icInteractiveModule :: InteractiveContext -> Module

icInScopeTTs :: InteractiveContext -> [TyThing]

This function returns the list of visible TyThings (useful for e.g. showBindings).

It picks only those TyThings that are not shadowed by later definitions on the interpreter, to not clutter :showBindings with shadowed ids, which would show up as Ghci9.foo.

Some TyThings define many names; we include them if _any_ name is still available unqualified.

icNamePprCtx :: UnitEnv -> InteractiveContext -> NamePprCtx

Get the NamePprCtx function based on the flags and this InteractiveContext