Text.Regex.TDFA.Pattern
Description
This Text.Regex.TDFA.Pattern module provides the Pattern data
type and its subtypes. This Pattern type is used to represent
the parsed form of a Regular Expression.
- data Pattern
- = PEmpty
- | PGroup (Maybe GroupIndex) Pattern
- | POr [Pattern]
- | PConcat [Pattern]
- | PQuest Pattern
- | PPlus Pattern
- | PStar Bool Pattern
- | PBound Int (Maybe Int) Pattern
- | PCarat { }
- | PDollar { }
- | PDot { }
- | PAny { }
- | PAnyNot { }
- | PEscape {
- getDoPa :: DoPa
- getPatternChar :: Char
- | PChar {
- getDoPa :: DoPa
- getPatternChar :: Char
- | PNonCapture Pattern
- | PNonEmpty Pattern
- data PatternSet = PatternSet (Maybe (Set Char)) (Maybe (Set PatternSetCharacterClass)) (Maybe (Set PatternSetCollatingElement)) (Maybe (Set PatternSetEquivalenceClass))
- newtype PatternSetCharacterClass = PatternSetCharacterClass {}
- newtype PatternSetCollatingElement = PatternSetCollatingElement {}
- newtype PatternSetEquivalenceClass = PatternSetEquivalenceClass {}
- type GroupIndex = Int
- newtype DoPa = DoPa {}
- showPattern :: Pattern -> String
- starTrans :: Pattern -> Pattern
- starTrans' :: Pattern -> Pattern
- simplify' :: Pattern -> Pattern
- dfsPattern :: (Pattern -> Pattern) -> Pattern -> Pattern
Documentation
Pattern is the type returned by the regular expression parser. This is consumed by the CorePattern module and the tender leaves are nibbled by the TNFA module.
Constructors
| PEmpty | |
| PGroup (Maybe GroupIndex) Pattern | |
| POr [Pattern] | |
| PConcat [Pattern] | |
| PQuest Pattern | |
| PPlus Pattern | |
| PStar Bool Pattern | |
| PBound Int (Maybe Int) Pattern | |
| PCarat | |
| PDollar | |
| PDot | |
| PAny | |
Fields
| |
| PAnyNot | |
Fields
| |
| PEscape | |
Fields
| |
| PChar | |
Fields
| |
| PNonCapture Pattern | |
| PNonEmpty Pattern | |
data PatternSet Source
Constructors
| PatternSet (Maybe (Set Char)) (Maybe (Set PatternSetCharacterClass)) (Maybe (Set PatternSetCollatingElement)) (Maybe (Set PatternSetEquivalenceClass)) |
Instances
newtype PatternSetCharacterClass Source
Constructors
| PatternSetCharacterClass | |
newtype PatternSetCollatingElement Source
Constructors
| PatternSetCollatingElement | |
newtype PatternSetEquivalenceClass Source
Constructors
| PatternSetEquivalenceClass | |
type GroupIndex = IntSource
GroupIndex is for indexing submatches from capturing parenthesized groups (PGroup/Group)
Used to track elements of the pattern that accept characters or are anchors
showPattern :: Pattern -> StringSource
I have not been checking, but this should have the property that parsing the resulting string should result in an identical Pattern. This is not true if starTrans has created PNonCapture and PNonEmpty values or a (PStar False). The contents of a [ ] grouping are always shown in a sorted canonical order.
Internal use
starTrans :: Pattern -> PatternSource
Do the transformation and simplification in a single traversal. This removes the PPlus, PQuest, and PBound values, changing to POr and PEmpty and PStar True/False. For some PBound values it adds PNonEmpty and PNonCapture semantic marker. It also simplifies to flatten out nested POr and PConcat instances and eliminate some uneeded PEmpty values.
Internal use, Operations to support debugging under ghci
starTrans' :: Pattern -> PatternSource