Safe Haskell	Safe-Inferred
Language	Haskell2010

Deka.Native.FromString

Description

Uses the specification for string conversions given in the General Decimal Arithmetic Specification to convert strings to an abstract syntax tree. The specification for string conversions is at

http://speleotrove.com/decimal/daconvs.html

The functions and types in this module fall into two groups. The first group converts a string to a NumericString, which is an abstract representation of the grammar given in the General Decimal Arithmetic Specification. These functions use Parsec to parse the string. The second group transforms the NumericString to an A.Abstract, a form which more closely aligns with the abstract representation given at

http://speleotrove.com/decimal/damodel.html.

You can transform an A.Abstract to a numeric string; no functions are provided to transform a NumericString directly back to a string.

Synopsis

Documentation

sign :: Parser D.Sign Source

optSign :: Parser D.Sign Source

digit :: Parser A.Decem Source

indicator :: Parser () Source

digits :: Parser [A.Decem] Source

data DecimalPart Source

Constructors

WholeFrac [A.Decem] [A.Decem]
WholeOnly [A.Decem]

Instances

Eq DecimalPart
Ord DecimalPart
Show DecimalPart

decimalPart :: Parser DecimalPart Source

data ExponentPart Source

Constructors

ExponentPart
Fields expSign :: D.Sign expDigits :: [A.Decem]

Instances

Eq ExponentPart
Ord ExponentPart
Show ExponentPart

exponentPart :: Parser ExponentPart Source

infinity :: Parser () Source

nanId :: Parser A.Noisy Source

data NaN Source

Constructors

NaN A.Noisy [A.Decem]

Instances

Eq NaN
Ord NaN
Show NaN

nan :: Parser NaN Source

data NumericValue Source

Constructors

NVDec DecimalPart (Maybe ExponentPart)
Infinity

Instances

Eq NumericValue
Ord NumericValue
Show NumericValue

numericValue :: Parser NumericValue Source

data NumericString Source

Constructors

NumericString
Fields nsSign :: D.Sign nsValue :: Either NumericValue NaN

Instances

Eq NumericString
Ord NumericString
Show NumericString

numericString :: Parser NumericString Source

parseNumericString :: String -> Either String NumericString Source

numericStringToAbstract :: NumericString -> A.Abstract Source

nanToAbstract :: NaN -> A.NonNum Source

finiteToAbstract :: DecimalPart -> Maybe ExponentPart -> (A.Coefficient, A.Exponent) Source

givenExponent :: Maybe ExponentPart -> Integer Source

A numeric value for the exponent that was given in the input string.

actualExponent Source

Arguments

:: DecimalPart
-> Integer	Output from `givenExponent`
-> Integer

The number of digits after the decimal point, subtracted from the numeric value for the exponent given in the string

abstractExponent Source

Arguments

:: Integer	The output from `actualExponent`
-> A.Exponent

abstractCoeff :: DecimalPart -> A.Coefficient Source

stringToAbstract Source

Arguments

:: String	Input string
-> Either String A.Abstract	Returns a Right with the abstract representation of the input string, if the input conformed to the numeric string specification given in the General Decimal Arithmetic Specification. Otherwise, returns a Left with an error message.

decToAbstract :: D.Dec -> A.Abstract Source

Transforms a Dec to an Abstract.