Data.Textual.Fractional

Parsers for fractions.

Positional numeral systems

class PositionalSystem s where

Positional numeral system.

Methods

systemName :: s -> String

The name of the system (e.g. "binary", "decimal").

radixIn :: Num α => s -> α

The radix of the system.

isDigitIn :: s -> Char -> Bool

Test if a character is a digit.

isNzDigitIn :: s -> Char -> Bool

Test if a character is a non-zero digit.

fromDigitIn :: Num α => s -> Char -> Maybe α

Map digits to the corresponding numbers. Return Nothing on other inputs.

fromNzDigitIn :: Num α => s -> Char -> Maybe α

Map non-zero digits to the corresponding numbers. Return Nothing on other inputs.

unsafeFromDigitIn :: Num α => s -> Char -> α

Map digits to the corresponding numbers. No checks are performed.

intToDigitIn :: s -> Int -> Char

Map Int values to the corresponding digits. Inputs must be non-negative and less than the radix.

printDigitIn :: Printer p => s -> Char -> p

Print a digit.

printZeroIn :: Printer p => s -> p

Instances

PositionalSystem Binary

PositionalSystem Octal

PositionalSystem Decimal

PositionalSystem Hexadecimal

PositionalSystem LowHex

PositionalSystem UpHex

data Binary

The binary numeral system.

Constructors

Binary

Instances

Eq Binary

Ord Binary

Read Binary

Show Binary

Typeable Binary

PositionalSystem Binary

BitSystem Binary

data Octal

The octal numeral system.

Constructors

Octal

Instances

Eq Octal

Ord Octal

Read Octal

Show Octal

Typeable Octal

PositionalSystem Octal

BitSystem Octal

data Decimal

The decimal numeral system.

Constructors

Decimal

Instances

Eq Decimal

Ord Decimal

Read Decimal

Show Decimal

Typeable Decimal

PositionalSystem Decimal

data Hexadecimal

The hexadecimal numeral system.

Constructors

Hexadecimal

Instances

PositionalSystem Hexadecimal

BitSystem Hexadecimal

data UpHex

The hexadecimal numeral system, using upper case digits.

Constructors

UpHex

Instances

PositionalSystem UpHex

BitSystem UpHex

data LowHex

The hexadecimal numeral system, using lower case digits.

Constructors

LowHex

Instances

PositionalSystem LowHex

BitSystem LowHex

Sign

data Sign

Sign of a number.

Constructors

NonNegative

NonPositive

Instances

Eq Sign

Read Sign

Show Sign

Typeable Sign

applySign :: Num α => Sign -> α -> α

Negate the supplied value if the sign is NonPositive and return it as it is otherwise.

optMinus :: CharParsing μ => μ Sign

Optional minus sign.

optSign :: CharParsing μ => μ Sign

Optional minus or plus sign.

Optionality characteristic

data Optional

Optionality characteristic.

Constructors

Optional

Required

Instances

Bounded Optional

Enum Optional

Eq Optional

Ord Optional

Read Optional

Show Optional

Ix Optional

Typeable Optional

isOptional :: Optional -> Bool

True if the supplied value is Optional and false otherwise.

isRequired :: Optional -> Bool

True if the supplied value is Required and false otherwise.

Fraction parsers

optSlash :: (Monad μ, CharParsing μ) => μ Optional

Accept a slash and return Required. Otherwise return Optional.

fraction'

Arguments

:: (PositionalSystem s, Fractional α, Monad μ, CharParsing μ)

=> μ Sign

Sign parser

-> s

-> μ Optional

Numerator/denominator separator parser

-> μ α

Parse a fraction. The numerator and the denominator are expected to be written in the specified positional numeral system.

fraction :: (Fractional α, Monad μ, CharParsing μ) => μ α

A shorthand for fraction' optMinus Decimal optSlash.

s-fraction parsers

decExpSign :: (Monad μ, CharParsing μ) => μ (Maybe Sign)

Start of a decimal exponent. Accepts 'e' or 'E' followed by an optional sign. Otherwise Nothing is returned.

hexExpSign :: (Monad μ, CharParsing μ) => μ (Maybe Sign)

Start of a hexadecimal exponent. Accepts 'p' or 'P' followed by an optional sign. Otherwise Nothing is returned.

fractional'

Arguments

:: (PositionalSystem s, Fractional α, Monad μ, CharParsing μ)

=> μ Sign

Sign parser.

-> s

-> Optional

Whether the integer part is optional.

-> μ ()

Dot parser.

-> μ (Maybe Sign)

Exponent start parser.

-> μ α

s-fraction parser.

fractional :: (Monad μ, Fractional α, CharParsing μ) => μ α

Decimal fraction parser.