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GHC 10.0.0.20260917 · lts/ghc-10.0.x · 8174fa4 · 2026-10-11

Moduleghc-tcplugins-extra-0.5Haskell2010

GHC.TcPluginM.Extra

12 values
Cpp

Packageghc-tcplugins-extra-0.5
Exports12
LanguageHaskell2010
LicenceBSD-2-Clause
SourcePlugin.hs

Create new constraints

2 declarations

valuenewWanted :: CtLoc -> PredType -> TcPluginM CtEvidence

Create a new Wanted constraint with the given CtLoc.

valuenewGiven

Create a new [G]iven constraint, with the supplied evidence. This must not be invoked from tcPluginInit or tcPluginStop, or it will panic.

Creating evidence

2 declarations

valueevByFiatWithDependencies

:: String
Name the coercion should have
-> [Coercion]
The set of all the in-scope coercion that the proof makes use of.
-> Type
The LHS of the equivalence relation (~)
-> Type
The RHS of the equivalence relation (~)
-> EvTerm

The EvTerm equivalent for Unsafe.unsafeCoerce

valueevByFiat

:: String
Name the coercion should have
-> Type
The LHS of the equivalence relation (~)
-> Type
The RHS of the equivalence relation (~)
-> EvTerm

Deprecated. evByFiat creates proofs that can lead to unsoundness, use evByFiatWithDependencies instead. See also https://gitlab.haskell.org/ghc/ghc/-/merge_requests/12037

The EvTerm equivalent for Unsafe.unsafeCoerce

Lookup

2 declarations

valuelookupModule

:: ModuleName
Name of the module
-> FastString
Name of the package containing the module. NOTE: This value is ignored on ghc>=8.0.
-> TcPluginM Module

Find a module

valuelookupName :: Module -> OccName -> TcPluginM Name

Find a Name in a Module given an OccName

Trace state of the plugin

1 declaration

valuetracePlugin :: String -> TcPlugin -> TcPlugin

Print out extra information about the initialisation, stop, and every run of the plugin when -ddump-tc-trace is enabled.

Substitutions

5 declarations

valueflattenGivens :: [Ct] -> [Ct]

Flattens evidence of constraints by substituting each others equalities.

NB: Should only be used on [G]iven constraints!

NB: Doesn't flatten under binders

valuemkSubst :: Ct -> Maybe ((TcTyVar, TcType), Ct)

Create simple substitution from type equalities

valuemkSubst' :: [Ct] -> [((TcTyVar, TcType), Ct)]

Create flattened substitutions from type equalities, i.e. the substitutions have been applied to each others right hand sides.

valuesubstType :: [(TcTyVar, TcType)] -> TcType -> TcType

Apply substitutions in Types

NB: Doesn't substitute under binders

valuesubstCt :: [(TcTyVar, TcType)] -> Ct -> Ct

Apply substitution in the evidence of Cts