Safe Haskell	Safe-Inferred
Language	Haskell2010

GHC.HsToCore.Pmc.Types

Contents

LYG syntax
- Guard language
- Guard tree language
Coverage Checking types
Pre and post coverage checking synonyms
Normalised refinement types

Description

Types used through-out pattern match checking. This module is mostly there to be imported from GHC.HsToCore.Types. The exposed API is that of GHC.HsToCore.Pmc.

These types model the paper Lower Your Guards: A Compositional Pattern-Match Coverage Checker".

Synopsis

newtype SrcInfo = SrcInfo (Located SDoc)
data PmGrd
- = PmCon {
  - pm_id :: !Id
  - pm_con_con :: !PmAltCon
  - pm_con_tvs :: ![TyVar]
  - pm_con_dicts :: ![EvVar]
  - pm_con_args :: ![Id]
  }
- | PmBang {
  - pm_id :: !Id
  - _pm_loc :: !(Maybe SrcInfo)
  }
- | PmLet {
  - pm_id :: !Id
  - _pm_let_expr :: !CoreExpr
  }
newtype GrdVec = GrdVec [PmGrd]
newtype PmMatchGroup p = PmMatchGroup (NonEmpty (PmMatch p))
data PmMatch p = PmMatch {
- pm_pats :: !p
- pm_grhss :: !(PmGRHSs p)
}
data PmGRHSs p = PmGRHSs {
- pgs_lcls :: !p
- pgs_grhss :: !(NonEmpty (PmGRHS p))
}
data PmGRHS p = PmGRHS {
- pg_grds :: !p
- pg_rhs :: !SrcInfo
}
newtype PmPatBind p = PmPatBind (PmGRHS p)
newtype PmEmptyCase = PmEmptyCase {
- pe_var :: Id
}
data RedSets = RedSets {
- rs_cov :: !Nablas
- rs_div :: !Nablas
- rs_bangs :: !(OrdList (Nablas, SrcInfo))
}
data Precision
- = Approximate
- | Precise
data CheckResult a = CheckResult {
- cr_ret :: !a
- cr_uncov :: !Nablas
- cr_approx :: !Precision
}
type Pre = GrdVec
type Post = RedSets
module GHC.HsToCore.Pmc.Solver.Types

LYG syntax

Guard language

newtype SrcInfo Source #

Means by which we identify a source construct for later pretty-printing in a warning message. SDoc for the equation to show, Located for the location.

Constructors

SrcInfo (Located SDoc)

Instances

Instances details

Outputable SrcInfo Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods ppr :: SrcInfo -> SDoc Source #

data PmGrd Source #

A very simple language for pattern guards. Let bindings, bang patterns, and matching variables against flat constructor patterns. The LYG guard language.

Constructors

PmCon	`PmCon x K dicts args` corresponds to a `K dicts args <- x` guard. The `args` are bound in this construct, the `x` is just a use. For the arguments' meaning see `ConPatOut`.
Fields pm_id :: !Id pm_con_con :: !PmAltCon pm_con_tvs :: ![TyVar] pm_con_dicts :: ![EvVar] pm_con_args :: ![Id]
PmBang	`PmBang x` corresponds to a `seq x True` guard. If the extra `SrcInfo` is present, the bang guard came from a source bang pattern, in which case we might want to report it as redundant. See Note [Dead bang patterns] in GHC.HsToCore.Pmc.Check.
Fields pm_id :: !Id _pm_loc :: !(Maybe SrcInfo)
PmLet	`PmLet x expr` corresponds to a `let x = expr` guard. This actually binds `x`.
Fields pm_id :: !Id _pm_let_expr :: !CoreExpr

Instances

Instances details

Outputable PmGrd Source #	Should not be user-facing.
Instance details Defined in GHC.HsToCore.Pmc.Types Methods ppr :: PmGrd -> SDoc Source #

newtype GrdVec Source #

A sequence of PmGrds.

Constructors

GrdVec [PmGrd]

Instances

Instances details

Outputable GrdVec Source #	Format LYG guards as `\| True <- x, let x = 42, !z`
Instance details Defined in GHC.HsToCore.Pmc.Types Methods ppr :: GrdVec -> SDoc Source #

A guard tree denoting GRHSs: A bunch of PmLet guards for local bindings from the GRHSss where clauses and the actual list of GRHS. See Note [Long-distance information for HsLocalBinds] in GHC.HsToCore.Pmc.Desugar.

Constructors

PmGRHSs
Fields pgs_lcls :: !p pgs_grhss :: !(NonEmpty (PmGRHS p))

Instances

Instances details

Outputable p => Outputable (PmGRHSs p) Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods ppr :: PmGRHSs p -> SDoc Source #

data PmGRHS p Source #

A guard tree denoting GRHS: A payload describing the grds and a SrcInfo useful for printing out in warnings messages.

Constructors

PmGRHS
Fields pg_grds :: !p pg_rhs :: !SrcInfo

Instances

Instances details

Outputable p => Outputable (PmGRHS p) Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods ppr :: PmGRHS p -> SDoc Source #

newtype PmPatBind p Source #

A guard tree denoting a pattern binding.

Constructors

PmPatBind (PmGRHS p)

Instances

Instances details

Outputable p => Outputable (PmPatBind p) Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods ppr :: PmPatBind p -> SDoc Source #

newtype PmEmptyCase Source #

A guard tree denoting an -XEmptyCase.

Constructors

PmEmptyCase
Fields pe_var :: Id

Instances

Instances details

Outputable PmEmptyCase Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods ppr :: PmEmptyCase -> SDoc Source #

Coverage Checking types

data RedSets Source #

Redundancy sets, used to determine redundancy of RHSs and bang patterns (later digested into a CIRB).

Constructors

RedSets

Fields

rs_cov :: !Nablas
The Covered set; the set of values reaching a particular program point.
rs_div :: !Nablas
The Diverging set; empty if no match can lead to divergence. If it wasn't empty, we have to turn redundancy warnings into inaccessibility warnings for any subclauses.
rs_bangs :: !(OrdList (Nablas, SrcInfo))
If any of the Nablas is empty, the corresponding SrcInfo pin-points a bang pattern in source that is redundant. See Note [Dead bang patterns].

Instances

Instances details

Outputable RedSets Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods ppr :: RedSets -> SDoc Source #

data Precision Source #

Constructors

Approximate
Precise

Instances

Instances details

Monoid Precision Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods mempty :: Precision # mappend :: Precision -> Precision -> Precision # mconcat :: [Precision] -> Precision #
Semigroup Precision Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods (<>) :: Precision -> Precision -> Precision # sconcat :: NonEmpty Precision -> Precision # stimes :: Integral b => b -> Precision -> Precision #
Show Precision Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods showsPrec :: Int -> Precision -> ShowS # show :: Precision -> String # showList :: [Precision] -> ShowS #
Outputable Precision Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods ppr :: Precision -> SDoc Source #
Eq Precision Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods (==) :: Precision -> Precision -> Bool # (/=) :: Precision -> Precision -> Bool #

data CheckResult a Source #

Pattern-match coverage check result

Constructors

CheckResult
Fields cr_ret :: !a A hole for redundancy info and covered sets. cr_uncov :: !Nablas The set of uncovered values falling out at the bottom. (for -Wincomplete-patterns, but also important state for the algorithm) cr_approx :: !Precision A flag saying whether we ran into the `maxPmCheckModels` limit for the purpose of suggesting to crank it up in the warning message. Writer state.

Instances

Instances details

Functor CheckResult Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods fmap :: (a -> b) -> CheckResult a -> CheckResult b # (<$) :: a -> CheckResult b -> CheckResult a #
Outputable a => Outputable (CheckResult a) Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods ppr :: CheckResult a -> SDoc Source #

Pre and post coverage checking synonyms

type Pre = GrdVec Source #

Used as tree payload pre-checking. The LYG guards to check.

type Post = RedSets Source #

Used as tree payload post-checking. The redundancy info we elaborated.

Normalised refinement types

module GHC.HsToCore.Pmc.Solver.Types

Outputable p => Outputable (PmMatchGroup p) Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods ppr :: PmMatchGroup p -> SDoc Source #

Outputable p => Outputable (PmMatch p) Source #
Instance details Defined in GHC.HsToCore.Pmc.Types Methods ppr :: PmMatch p -> SDoc Source #

PmMatch
Fields pm_pats :: !p pm_grhss :: !(PmGRHSs p)

LYG syntax

Guard language

Instances

Instances

Instances

Guard tree language

Instances

Instances

Instances

Instances

Instances

Instances

Coverage Checking types

Instances

Instances

Instances

Pre and post coverage checking synonyms

Normalised refinement types