Text.Regex.TDFA.CorePattern

The CorePattern module deconstructs the Pattern tree created by ReadRegex.parseRegex and returns a simpler Q/P tree with annotations at each Q node. This will be converted by the TNFA module into a QNFA finite automata.

Of particular note, this Pattern to Q/P conversion creates and assigns all the internal Tags that will be used during the matching process, and associates the captures groups with the tags that represent their starting and ending locations and with their immediate parent group.

Each Maximize and Minimize tag is held as either a preTag or a postTag by one and only one location in the Q/P tree. The Orbit tags are each held by one and only one Star node. Tags that stop a Group are also held in perhaps numerous preReset lists.

The additional nullQ::nullView field of Q records the potentially complex information about what tests and tags must be used if the pattern unQ::P matches 0 zero characters. There can be redundancy in nullView, which is eliminated by cleanNullView.

Uses recursive do notation.

2009 XXX TODO: we can avoid needing tags in the part of the pattern after the last capturing group (when right-associative). This is flipped for left-associative where the front of the pattern before the first capturing group needs no tags. The edge of these regions is subtle: both case needs a Maximize tag. One ought to be able to check the Pattern: if the root is PConcat then a scan from the end (start) looking for the first with an embedded PGroup can be found and the PGroup free elements can be wrapped in some new PNOTAG semantic indicator.

Documentation

data Q

Constructors

Q

Fields

• nullQ :: NullView
• takes :: (Position, Maybe Position)
• preReset :: [Tag]
• postSet :: [Tag]
• preTag, postTag :: Maybe Tag
• tagged :: Bool
• childGroups :: Bool
• wants :: Wanted
• unQ :: P

Instances

Eq Q

Defined in Text.Regex.TDFA.CorePattern

Methods

(==) :: Q -> Q -> Bool

(/=) :: Q -> Q -> Bool

Show Q

Defined in Text.Regex.TDFA.CorePattern

Methods

showsPrec :: Int -> Q -> ShowS

show :: Q -> String

showList :: [Q] -> ShowS

data P

Constructors

Empty

Or [Q]

Seq Q Q

Star

Fields

• getOrbit :: Maybe Tag
• resetOrbits :: [Tag]
• firstNull :: Bool
• unStar :: Q

Test TestInfo

OneChar Pattern

NonEmpty Q

Instances

Eq P

Defined in Text.Regex.TDFA.CorePattern

Methods

(==) :: P -> P -> Bool

(/=) :: P -> P -> Bool

Show P

Defined in Text.Regex.TDFA.CorePattern

Methods

showsPrec :: Int -> P -> ShowS

show :: P -> String

showList :: [P] -> ShowS

data WhichTest

Known predicates, just Beginning of Line (^) and End of Line ($). Also support for GNU extensions is being added: \` beginning of buffer, \' end of buffer, \< and \> for begin and end of words, \b and \B for word boundary and not word boundary.

Constructors

Test_BOL

Test_EOL

Test_BOB

Test_EOB

Test_BOW

Test_EOW

Test_EdgeWord

Test_NotEdgeWord

Instances

Enum WhichTest

Defined in Text.Regex.TDFA.Common

Methods

succ :: WhichTest -> WhichTest

pred :: WhichTest -> WhichTest

toEnum :: Int -> WhichTest

fromEnum :: WhichTest -> Int

enumFrom :: WhichTest -> [WhichTest]

enumFromThen :: WhichTest -> WhichTest -> [WhichTest]

enumFromTo :: WhichTest -> WhichTest -> [WhichTest]

enumFromThenTo :: WhichTest -> WhichTest -> WhichTest -> [WhichTest]

Eq WhichTest

Defined in Text.Regex.TDFA.Common

Methods

(==) :: WhichTest -> WhichTest -> Bool

(/=) :: WhichTest -> WhichTest -> Bool

Ord WhichTest

Defined in Text.Regex.TDFA.Common

Methods

compare :: WhichTest -> WhichTest -> Ordering

(<) :: WhichTest -> WhichTest -> Bool

(<=) :: WhichTest -> WhichTest -> Bool

(>) :: WhichTest -> WhichTest -> Bool

(>=) :: WhichTest -> WhichTest -> Bool

max :: WhichTest -> WhichTest -> WhichTest

min :: WhichTest -> WhichTest -> WhichTest

Show WhichTest

Defined in Text.Regex.TDFA.Common

Methods

showsPrec :: Int -> WhichTest -> ShowS

show :: WhichTest -> String

showList :: [WhichTest] -> ShowS

data Wanted

Constructors

WantsQNFA

WantsQT

WantsBoth

WantsEither

Instances

Eq Wanted

Defined in Text.Regex.TDFA.CorePattern

Methods

(==) :: Wanted -> Wanted -> Bool

(/=) :: Wanted -> Wanted -> Bool

Show Wanted

Defined in Text.Regex.TDFA.CorePattern

Methods

showsPrec :: Int -> Wanted -> ShowS

show :: Wanted -> String

showList :: [Wanted] -> ShowS

type TestInfo = (WhichTest, DoPa)

data OP

Internal use to indicate type of tag and preference for larger or smaller Positions

Constructors

Maximize

Minimize

Orbit

Ignore

Instances

Eq OP

Defined in Text.Regex.TDFA.Common

Methods

(==) :: OP -> OP -> Bool

(/=) :: OP -> OP -> Bool

Show OP

Defined in Text.Regex.TDFA.Common

Methods

showsPrec :: Int -> OP -> ShowS

show :: OP -> String

showList :: [OP] -> ShowS

newtype SetTestInfo

Constructors

SetTestInfo

Fields

• getTests :: EnumMap WhichTest (EnumSet DoPa)

Instances

Eq SetTestInfo

Defined in Text.Regex.TDFA.CorePattern

Methods

(==) :: SetTestInfo -> SetTestInfo -> Bool

(/=) :: SetTestInfo -> SetTestInfo -> Bool

Show SetTestInfo

Defined in Text.Regex.TDFA.CorePattern

Methods

showsPrec :: Int -> SetTestInfo -> ShowS

show :: SetTestInfo -> String

showList :: [SetTestInfo] -> ShowS

Semigroup SetTestInfo

Defined in Text.Regex.TDFA.CorePattern

Methods

(<>) :: SetTestInfo -> SetTestInfo -> SetTestInfo

sconcat :: NonEmpty SetTestInfo -> SetTestInfo

stimes :: Integral b => b -> SetTestInfo -> SetTestInfo

Monoid SetTestInfo

Defined in Text.Regex.TDFA.CorePattern

Methods

mempty :: SetTestInfo

mappend :: SetTestInfo -> SetTestInfo -> SetTestInfo

mconcat :: [SetTestInfo] -> SetTestInfo

type NullView = [(SetTestInfo, TagList)]

patternToQ :: CompOption -> (Pattern, (GroupIndex, DoPa)) -> (Q, Array Tag OP, Array GroupIndex [GroupInfo])

cleanNullView :: NullView -> NullView

cannotAccept :: Q -> Bool

mustAccept :: Q -> Bool