BNFC-2.9.1: A compiler front-end generator.
Safe HaskellNone




parserName :: Cat -> Doc Source #

Create a valid parser function name for a given category.

>>> parserName (Cat "Abcd")
>>> parserName (ListCat (Cat "Xyz"))

hsReservedWords :: [String] Source #

Haskell's reserved words.

avoidReservedWords :: [String] -> String -> String Source #

Avoid Haskell keywords plus additional reserved words.

mkDefName :: IsFun f => f -> String Source #

Modifier to avoid clashes in definition.

typeToHaskell :: Type -> String Source #

Convert a function type to Haskell syntax in curried form.

catToType :: (Doc -> Doc) -> Doc -> Cat -> Doc Source #

Render a category from the grammar to a Haskell type.

>>> catToType id empty (Cat "A")
>>> catToType id empty (ListCat (Cat "A"))
>>> catToType ("Foo." P.<>) empty (TokenCat "Ident")

Note that there is no haskell type for coerced categories: they should be normalized: >>> catToType id empty (CoercCat Expr 2) Expr

If a type parameter is given it is added to the type name: >>> catToType id (text "a") (Cat A) (A a)

>>> catToType id (text "a") (ListCat (Cat "A"))
[A a]

but not added to Token categories: >>> catToType ("Foo." P.<>) (text "a") (TokenCat Integer) Integer

>>> catToType id (text "a") (ListCat (TokenCat "Integer"))
>>> catToType id empty (ListCat (CoercCat "Exp" 2))
>>> catToType ("Foo." P.<>) (text "()") (ListCat (CoercCat "Exp" 2))
[Foo.Exp ()]

catToVar :: [String] -> Cat -> String Source #

Make a variable name for a category.

catvars :: [String] -> [Cat] -> [Doc] Source #

Gives a list of variables usable for pattern matching.

Example: Given the rule Aba. S ::= A B A ; with the generated data type data S = Aba A B A from the list of categories on the RHS of the rule [A,B,A], we generate the list [a1,b,a2] to be used in a pattern matching like case s of Aba a1 b a2 -> ... ...

>>> catvars [] [Cat "A", Cat "B", Cat "A"]

It should avoid reserved words: >>> catvars ["foo"] [Cat Foo, Cat IF, Cat Case, Cat Type, Cat If] [foo_,if_1,case_,type_,if_2]

It uses a suffix -s to mark lists: >>> catvars [] [Cat A, ListCat (Cat A), ListCat (ListCat (Cat A))] [a,as_,ass]