base-4.20.0.0: Core data structures and operations
Copyright(c) The University of Glasgow 2003
Licensesee libraries/base/LICENSE
Maintainerghc-devs@haskell.org
Stabilityinternal
Portabilitynon-portable (GHC extensions)
Safe HaskellSafe
LanguageHaskell2010

GHC.Unicode

Description

Implementations for the character predicates (isLower, isUpper, etc.) and the conversions (toUpper, toLower). The implementation uses libunicode on Unix systems if that is available.

Synopsis

Documentation

unicodeVersion :: Version Source #

Version of Unicode standard used by base: 15.1.0.

Since: base-4.15.0.0

data GeneralCategory Source #

Unicode General Categories (column 2 of the UnicodeData table) in the order they are listed in the Unicode standard (the Unicode Character Database, in particular).

Examples

Expand

Basic usage:

>>> :t OtherLetter
OtherLetter :: GeneralCategory

Eq instance:

>>> UppercaseLetter == UppercaseLetter
True
>>> UppercaseLetter == LowercaseLetter
False

Ord instance:

>>> NonSpacingMark <= MathSymbol
True

Enum instance:

>>> enumFromTo ModifierLetter SpacingCombiningMark
[ModifierLetter,OtherLetter,NonSpacingMark,SpacingCombiningMark]

Read instance:

>>> read "DashPunctuation" :: GeneralCategory
DashPunctuation
>>> read "17" :: GeneralCategory
*** Exception: Prelude.read: no parse

Show instance:

>>> show EnclosingMark
"EnclosingMark"

Bounded instance:

>>> minBound :: GeneralCategory
UppercaseLetter
>>> maxBound :: GeneralCategory
NotAssigned

Ix instance:

>>> import GHC.Internal.Data.Ix ( index )
>>> index (OtherLetter,Control) FinalQuote
12
>>> index (OtherLetter,Control) Format
*** Exception: Error in array index

Constructors

UppercaseLetter

Lu: Letter, Uppercase

LowercaseLetter

Ll: Letter, Lowercase

TitlecaseLetter

Lt: Letter, Titlecase

ModifierLetter

Lm: Letter, Modifier

OtherLetter

Lo: Letter, Other

NonSpacingMark

Mn: Mark, Non-Spacing

SpacingCombiningMark

Mc: Mark, Spacing Combining

EnclosingMark

Me: Mark, Enclosing

DecimalNumber

Nd: Number, Decimal

LetterNumber

Nl: Number, Letter

OtherNumber

No: Number, Other

ConnectorPunctuation

Pc: Punctuation, Connector

DashPunctuation

Pd: Punctuation, Dash

OpenPunctuation

Ps: Punctuation, Open

ClosePunctuation

Pe: Punctuation, Close

InitialQuote

Pi: Punctuation, Initial quote

FinalQuote

Pf: Punctuation, Final quote

OtherPunctuation

Po: Punctuation, Other

MathSymbol

Sm: Symbol, Math

CurrencySymbol

Sc: Symbol, Currency

ModifierSymbol

Sk: Symbol, Modifier

OtherSymbol

So: Symbol, Other

Space

Zs: Separator, Space

LineSeparator

Zl: Separator, Line

ParagraphSeparator

Zp: Separator, Paragraph

Control

Cc: Other, Control

Format

Cf: Other, Format

Surrogate

Cs: Other, Surrogate

PrivateUse

Co: Other, Private Use

NotAssigned

Cn: Other, Not Assigned

Instances

Instances details
Bounded GeneralCategory Source #

Since: base-2.1

Instance details

Defined in GHC.Internal.Unicode

Enum GeneralCategory Source #

Since: base-2.1

Instance details

Defined in GHC.Internal.Unicode

Generic GeneralCategory Source # 
Instance details

Defined in GHC.Internal.Generics

Associated Types

type Rep GeneralCategory

Since: base-4.15.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep GeneralCategory = D1 ('MetaData "GeneralCategory" "GHC.Internal.Unicode" "ghc-internal" 'False) ((((C1 ('MetaCons "UppercaseLetter" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "LowercaseLetter" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "TitlecaseLetter" 'PrefixI 'False) (U1 :: Type -> Type))) :+: ((C1 ('MetaCons "ModifierLetter" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "OtherLetter" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "NonSpacingMark" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "SpacingCombiningMark" 'PrefixI 'False) (U1 :: Type -> Type)))) :+: (((C1 ('MetaCons "EnclosingMark" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "DecimalNumber" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "LetterNumber" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "OtherNumber" 'PrefixI 'False) (U1 :: Type -> Type))) :+: ((C1 ('MetaCons "ConnectorPunctuation" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "DashPunctuation" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "OpenPunctuation" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "ClosePunctuation" 'PrefixI 'False) (U1 :: Type -> Type))))) :+: (((C1 ('MetaCons "InitialQuote" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "FinalQuote" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "OtherPunctuation" 'PrefixI 'False) (U1 :: Type -> Type))) :+: ((C1 ('MetaCons "MathSymbol" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "CurrencySymbol" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "ModifierSymbol" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "OtherSymbol" 'PrefixI 'False) (U1 :: Type -> Type)))) :+: (((C1 ('MetaCons "Space" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "LineSeparator" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "ParagraphSeparator" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Control" 'PrefixI 'False) (U1 :: Type -> Type))) :+: ((C1 ('MetaCons "Format" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Surrogate" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "PrivateUse" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "NotAssigned" 'PrefixI 'False) (U1 :: Type -> Type))))))
Ix GeneralCategory Source #

Since: base-2.1

Instance details

Defined in GHC.Internal.Unicode

Read GeneralCategory Source #

Since: base-2.1

Instance details

Defined in GHC.Internal.Read

Show GeneralCategory Source #

Since: base-2.1

Instance details

Defined in GHC.Internal.Unicode

Eq GeneralCategory Source #

Since: base-2.1

Instance details

Defined in GHC.Internal.Unicode

Ord GeneralCategory Source #

Since: base-2.1

Instance details

Defined in GHC.Internal.Unicode

type Rep GeneralCategory Source #

Since: base-4.15.0.0

Instance details

Defined in GHC.Internal.Generics

type Rep GeneralCategory = D1 ('MetaData "GeneralCategory" "GHC.Internal.Unicode" "ghc-internal" 'False) ((((C1 ('MetaCons "UppercaseLetter" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "LowercaseLetter" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "TitlecaseLetter" 'PrefixI 'False) (U1 :: Type -> Type))) :+: ((C1 ('MetaCons "ModifierLetter" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "OtherLetter" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "NonSpacingMark" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "SpacingCombiningMark" 'PrefixI 'False) (U1 :: Type -> Type)))) :+: (((C1 ('MetaCons "EnclosingMark" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "DecimalNumber" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "LetterNumber" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "OtherNumber" 'PrefixI 'False) (U1 :: Type -> Type))) :+: ((C1 ('MetaCons "ConnectorPunctuation" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "DashPunctuation" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "OpenPunctuation" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "ClosePunctuation" 'PrefixI 'False) (U1 :: Type -> Type))))) :+: (((C1 ('MetaCons "InitialQuote" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "FinalQuote" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "OtherPunctuation" 'PrefixI 'False) (U1 :: Type -> Type))) :+: ((C1 ('MetaCons "MathSymbol" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "CurrencySymbol" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "ModifierSymbol" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "OtherSymbol" 'PrefixI 'False) (U1 :: Type -> Type)))) :+: (((C1 ('MetaCons "Space" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "LineSeparator" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "ParagraphSeparator" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Control" 'PrefixI 'False) (U1 :: Type -> Type))) :+: ((C1 ('MetaCons "Format" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Surrogate" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "PrivateUse" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "NotAssigned" 'PrefixI 'False) (U1 :: Type -> Type))))))

generalCategory :: Char -> GeneralCategory Source #

The Unicode general category of the character. This relies on the Enum instance of GeneralCategory, which must remain in the same order as the categories are presented in the Unicode standard.

Examples

Expand

Basic usage:

>>> generalCategory 'a'
LowercaseLetter
>>> generalCategory 'A'
UppercaseLetter
>>> generalCategory '0'
DecimalNumber
>>> generalCategory '%'
OtherPunctuation
>>> generalCategory '♥'
OtherSymbol
>>> generalCategory '\31'
Control
>>> generalCategory ' '
Space

isAscii :: Char -> Bool Source #

Selects the first 128 characters of the Unicode character set, corresponding to the ASCII character set.

isLatin1 :: Char -> Bool Source #

Selects the first 256 characters of the Unicode character set, corresponding to the ISO 8859-1 (Latin-1) character set.

isControl :: Char -> Bool Source #

Selects control characters, which are the non-printing characters of the Latin-1 subset of Unicode.

isAsciiUpper :: Char -> Bool Source #

Selects ASCII upper-case letters, i.e. characters satisfying both isAscii and isUpper.

isAsciiLower :: Char -> Bool Source #

Selects ASCII lower-case letters, i.e. characters satisfying both isAscii and isLower.

isPrint :: Char -> Bool Source #

Selects printable Unicode characters (letters, numbers, marks, punctuation, symbols and spaces).

This function returns False if its argument has one of the following GeneralCategorys, or True otherwise:

isSpace :: Char -> Bool Source #

Returns True for any Unicode space character, and the control characters \t, \n, \r, \f, \v.

isUpper :: Char -> Bool Source #

Selects upper-case or title-case alphabetic Unicode characters (letters). Title case is used by a small number of letter ligatures like the single-character form of Lj.

Note: this predicate does not work for letter-like characters such as: 'Ⓐ' (U+24B6 circled Latin capital letter A) and 'Ⅳ' (U+2163 Roman numeral four). This is due to selecting only characters with the GeneralCategory UppercaseLetter or TitlecaseLetter.

See isUpperCase for a more intuitive predicate. Note that unlike isUpperCase, isUpper does select title-case characters such as 'Dž' (U+01C5 Latin capital letter d with small letter z with caron) or 'ᾯ' (U+1FAF Greek capital letter omega with dasia and perispomeni and prosgegrammeni).

isUpperCase :: Char -> Bool Source #

Selects upper-case Unicode letter-like characters.

Note: this predicate selects characters with the Unicode property Uppercase, which include letter-like characters such as: 'Ⓐ' (U+24B6 circled Latin capital letter A) and 'Ⅳ' (U+2163 Roman numeral four).

See isUpper for the legacy predicate. Note that unlike isUpperCase, isUpper does select title-case characters such as 'Dž' (U+01C5 Latin capital letter d with small letter z with caron) or 'ᾯ' (U+1FAF Greek capital letter omega with dasia and perispomeni and prosgegrammeni).

Since: base-4.18.0.0

isLower :: Char -> Bool Source #

Selects lower-case alphabetic Unicode characters (letters).

Note: this predicate does not work for letter-like characters such as: 'ⓐ' (U+24D0 circled Latin small letter a) and 'ⅳ' (U+2173 small Roman numeral four). This is due to selecting only characters with the GeneralCategory LowercaseLetter.

See isLowerCase for a more intuitive predicate.

isLowerCase :: Char -> Bool Source #

Selects lower-case Unicode letter-like characters.

Note: this predicate selects characters with the Unicode property Lowercase, which includes letter-like characters such as: 'ⓐ' (U+24D0 circled Latin small letter a) and 'ⅳ' (U+2173 small Roman numeral four).

See isLower for the legacy predicate.

Since: base-4.18.0.0

isAlpha :: Char -> Bool Source #

Selects alphabetic Unicode characters (lower-case, upper-case and title-case letters, plus letters of caseless scripts and modifiers letters). This function is equivalent to isLetter.

This function returns True if its argument has one of the following GeneralCategorys, or False otherwise:

These classes are defined in the Unicode Character Database, part of the Unicode standard. The same document defines what is and is not a "Letter".

isDigit :: Char -> Bool Source #

Selects ASCII digits, i.e. '0'..'9'.

isOctDigit :: Char -> Bool Source #

Selects ASCII octal digits, i.e. '0'..'7'.

isHexDigit :: Char -> Bool Source #

Selects ASCII hexadecimal digits, i.e. '0'..'9', 'a'..'f', 'A'..'F'.

isAlphaNum :: Char -> Bool Source #

Selects alphabetic or numeric Unicode characters.

Note that numeric digits outside the ASCII range, as well as numeric characters which aren't digits, are selected by this function but not by isDigit. Such characters may be part of identifiers but are not used by the printer and reader to represent numbers, e.g., Roman numerals like V, full-width digits like '1' (aka '65297').

This function returns True if its argument has one of the following GeneralCategorys, or False otherwise:

isPunctuation :: Char -> Bool Source #

Selects Unicode punctuation characters, including various kinds of connectors, brackets and quotes.

This function returns True if its argument has one of the following GeneralCategorys, or False otherwise:

These classes are defined in the Unicode Character Database, part of the Unicode standard. The same document defines what is and is not a "Punctuation".

Examples

Expand

Basic usage:

>>> isPunctuation 'a'
False
>>> isPunctuation '7'
False
>>> isPunctuation '♥'
False
>>> isPunctuation '"'
True
>>> isPunctuation '?'
True
>>> isPunctuation '—'
True

isSymbol :: Char -> Bool Source #

Selects Unicode symbol characters, including mathematical and currency symbols.

This function returns True if its argument has one of the following GeneralCategorys, or False otherwise:

These classes are defined in the Unicode Character Database, part of the Unicode standard. The same document defines what is and is not a "Symbol".

Examples

Expand

Basic usage:

>>> isSymbol 'a'
False
>>> isSymbol '6'
False
>>> isSymbol '='
True

The definition of "math symbol" may be a little counter-intuitive depending on one's background:

>>> isSymbol '+'
True
>>> isSymbol '-'
False

toUpper :: Char -> Char Source #

Convert a letter to the corresponding upper-case letter, if any. Any other character is returned unchanged.

toLower :: Char -> Char Source #

Convert a letter to the corresponding lower-case letter, if any. Any other character is returned unchanged.

toTitle :: Char -> Char Source #

Convert a letter to the corresponding title-case or upper-case letter, if any. (Title case differs from upper case only for a small number of ligature letters.) Any other character is returned unchanged.