Moduleregex-tdfa-1.3.2.5Haskell2010

Text.Regex.TDFA.Pattern

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.

7 types
7 values

Packageregex-tdfa-1.3.2.5
Exports14
LanguageHaskell2010
LicenceBSD-3-Clause
SourcePattern.hs

datadata Pattern

Pattern is the type returned by the regular expression parser parseRegex. This is consumed by the Text.Regex.TDFA.CorePattern module and the tender leaves are nibbled by the Text.Regex.TDFA.TNFA module.

The DoPa field is the index of the component in the regex string r.

Constructors

PEmpty
(), matches the empty string.
PGroup (Maybe GroupIndex) Pattern
Group (r). Nothing indicates non-matching PGroup (never produced by parser parseRegex).
POr [Pattern]
Alternative r|s (flattened by starTrans).
PConcat [Pattern]
Sequence rs (flattened by starTrans).
PQuest Pattern
Zero or one repetitions r? (eliminated by starTrans).
PPlus Pattern
One or more repetitions r+ (eliminated by starTrans).
PStar Bool Pattern
Zero or more repetitions r*. True (default) means may accept the empty string on its first iteration.
PBound Int (Maybe Int) Pattern
Given number or repetitions r{n} or r{n,m} (eliminated by starTrans).
PCarat
^ matches beginning of input.
- getDoPa :: DoPa
PDollar
$ matches end of input.
- getDoPa :: DoPa
PDot
. matches any character.
- getDoPa :: DoPa
PAny
Bracket expression [...].
- getDoPa :: DoPa
- getPatternSet :: PatternSet
PAnyNot
Inverted bracket expression [^...].
- getDoPa :: DoPa
- getPatternSet :: PatternSet
PEscape
Backslashed character c, may have special meaning.
- getDoPa :: DoPa
- getPatternChar :: Char
PChar
Single character, matches given character.
- getDoPa :: DoPa
- getPatternChar :: Char
PNonCapture Pattern
Tag for internal use, introduced by starTrans.
PNonEmpty Pattern
Tag for internal use, introduced by starTrans.

Instances2Eq, Show

Eq PatternDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern
Show PatternDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern

datadata PatternSet

Content of a bracket expression [...] organized into characters, POSIX character classes (e.g. [[:alnum:]]), collating elements (e.g. [.ch.], unused), and equivalence classes (e.g. [=a=], treated as characters).

Constructors

PatternSet (Maybe (Set Char)) (Maybe (Set PatternSetCharacterClass)) (Maybe (Set PatternSetCollatingElement)) (Maybe (Set PatternSetEquivalenceClass))

Instances2Eq, Show

Eq PatternSetDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern
Show PatternSetDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern
Hand-rolled implementation, giving textual rather than Haskell representation.

newtypenewtype PatternSetCharacterClass

Content of [: :], e.g. "alnum" for [:alnum:].

Constructors

PatternSetCharacterClass
- unSCC :: String

Instances3Eq, Ord, Show

Eq PatternSetCharacterClassDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern
Ord PatternSetCharacterClassDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern
Show PatternSetCharacterClassDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern
Hand-rolled implementation, giving textual rather than Haskell representation.

newtypenewtype PatternSetCollatingElement

Content of [. .], e.g. "ch" for [.ch.].

Constructors

PatternSetCollatingElement
- unSCE :: String

Instances3Eq, Ord, Show

Eq PatternSetCollatingElementDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern
Ord PatternSetCollatingElementDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern
Show PatternSetCollatingElementDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern
Hand-rolled implementation, giving textual rather than Haskell representation.

newtypenewtype PatternSetEquivalenceClass

Content of [= =], e.g. "a" for [=a=].

Constructors

PatternSetEquivalenceClass
- unSEC :: String

Instances3Eq, Ord, Show

Eq PatternSetEquivalenceClassDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern
Ord PatternSetEquivalenceClassDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern
Show PatternSetEquivalenceClassDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Pattern
Hand-rolled implementation, giving textual rather than Haskell representation.

typetype GroupIndex = Int

GroupIndex is for indexing submatches from capturing parenthesized groups (PGroup or Group).

newtypenewtype DoPa

Used to track elements of the pattern that accept characters or are anchors.

Constructors

DoPa
- dopaIndex :: Int

Instances4Enum, Eq, Ord, Show

Enum DoPaDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Common
Eq DoPaDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Common
Ord DoPaDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Common
Show DoPaDefined in regex-tdfa-1.3.2.5 · Text.Regex.TDFA.Common

valuedecodeCharacterClass :: PatternSetCharacterClass -> String

This returns the strictly ascending list of characters represented by [: :] POSIX character classes. Unrecognized class names return an empty string.

valuedecodePatternSet :: PatternSet -> Set Char

decodePatternSet cannot handle collating element and treats equivalence classes as just their definition and nothing more.

valueshowPattern :: Pattern -> String

Internal use

1 declaration

valuestarTrans :: Pattern -> Pattern

Do the transformation and simplification in a single traversal. This removes the PPlus, PQuest, and PBound values, changing to POr and PEmpty and PStar. 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 unneeded PEmpty values.

Internal use, operations to support debugging under `ghci`

3 declarations

valuestarTrans' :: Pattern -> Pattern

valuesimplify' :: Pattern -> Pattern

Function to transform a pattern into an equivalent, but less redundant form. Nested POr and PConcat are flattened. PEmpty is propagated.

valuedfsPattern

:: (Pattern -> Pattern)
The transformation function.
-> Pattern
The Pattern to transform.
-> Pattern
The transformed Pattern.

Apply a Pattern transformation function depth first.

Constructors

Constructors

Constructors

Constructors

Constructors

Constructors

Internal use

Internal use, operations to support debugging under ghci

Internal use, operations to support debugging under `ghci`