Data.SCargot.Language.HaskLike

Documentation

This module is intended for simple, ad-hoc configuration or data formats that might not need their on rich structure but might benefit from a few various kinds of literals. The haskLikeParser understands identifiers as defined by R5RS, as well as string, integer, and floating-point literals as defined by the Haskell 2010 spec. It does not natively understand other data types, such as booleans, vectors, bitstrings.

data HaskLikeAtom

An atom type that understands Haskell-like values as well as Scheme-like identifiers.

Constructors

HSIdent Text

An identifier, parsed according to the R5RS Scheme standard

HSString Text

A string, parsed according to the syntax for string literals in the Haskell report

HSInt Integer

An arbitrary-sized integer value, parsed according to the syntax for integer literals in the Haskell report

HSFloat Double

A double-precision floating-point value, parsed according to the syntax for floats in the Haskell report

Instances

Eq HaskLikeAtom

Methods

(==) :: HaskLikeAtom -> HaskLikeAtom -> Bool

(/=) :: HaskLikeAtom -> HaskLikeAtom -> Bool

Show HaskLikeAtom

Methods

showsPrec :: Int -> HaskLikeAtom -> ShowS

show :: HaskLikeAtom -> String

showList :: [HaskLikeAtom] -> ShowS

IsString HaskLikeAtom

Methods

fromString :: String -> HaskLikeAtom

IsString (Located HaskLikeAtom)

Methods

fromString :: String -> Located HaskLikeAtom

haskLikeParser :: SExprParser HaskLikeAtom (SExpr HaskLikeAtom)

This SExprParser understands s-expressions that contain Scheme-like tokens, as well as string literals, integer literals, and floating-point literals. Each of these values is parsed according to the lexical rules in the Haskell report, so the same set of string escapes, numeric bases, and floating-point options are available. This spec does not parse comments and does not understand any reader macros.

>>> decode haskLikeParser "(0x01 \"\\x65lephant\")"
Right [SCons (SAtom (HSInt 1)) (SCons (SAtom (HSString "elephant")) SNil)]

haskLikePrinter :: SExprPrinter HaskLikeAtom (SExpr HaskLikeAtom)

This SExprPrinter emits s-expressions that contain Scheme-like tokens as well as string literals, integer literals, and floating-point literals, which will be emitted as the literals produced by Haskell's show function. This printer will produce a flat s-expression with no indentation of any kind.

>>> encode haskLikePrinter [L [A (HSInt 1), A (HSString "elephant")]]
"(1 \"elephant\")"

locatedHaskLikeParser :: SExprParser (Located HaskLikeAtom) (SExpr (Located HaskLikeAtom))

A haskLikeParser which produces Located values

>>> decode locatedHaskLikeParser $ pack "(0x01 \"\\x65lephant\")"
Right [SCons (SAtom (At (Span (line 1, column 2) (line 1, column 6)) (HSInt 1))) (SCons (SAtom (At (Span (line 1, column 7) (line 1, column 20)) (HSString "elephant"))) SNil)]

>>> decode locatedHaskLikeParser $ pack "(1 elephant)"
Right [SCons (SAtom (At (Span (line 1, column 2) (line 1, column 3)) (HSInt 1))) (SCons (SAtom (At (Span (line 1, column 4) (line 1, column 12)) (HSIdent "elephant"))) SNil)]

locatedHaskLikePrinter :: SExprPrinter (Located HaskLikeAtom) (SExpr (Located HaskLikeAtom))

A SExprPrinter for Located values. Works exactly like haskLikePrinter It ignores the location tags when printing the result.

>>> let (Right dec) = decode locatedHaskLikeParser $ pack "(1 elephant)"
[SCons (SAtom (At (Span (line 1, column 2) (line 1, column 3)) (HSInt 1))) (SCons (SAtom (At (Span (line 1, column 4) (line 1, column 12)) (HSIdent "elephant"))) SNil)]

>>> encode locatedHaskLikePrinter dec
"(1 elephant)"

Individual Parsers

parseHaskellString :: Parser Text

Parse a Haskell string literal as defined by the Haskell 2010 language specification.

parseHaskellFloat :: Parser Double

Parse a Haskell floating-point number as defined by the Haskell 2010 language specification.

parseHaskellInt :: Parser Integer

Parse a Haskell integer literal as defined by the Haskell 2010 language specification.