Language.GroteTrap.Language

The Language type that is the core of GroteTrap.

Language

data Language a

Language connects the syntax of identifiers, numbers, operators and functions with their semantics. GroteTrap is able to derive a parser and evaluator from a Language, as well as convert between source text selections and tree selections.

Constructors

Language

Fields

variable :: Maybe (String -> a)

number :: Maybe (Int -> a)

operators :: [Operator a]

functions :: [Function a]

language :: Language a

An empty language. Use this as the starting base of your languages, setting only those fields that are of importance.

Operators

data Operator a

Representation of an operator.

Constructors

Unary

An operator expecting one operand.

Fields

opSem1 :: a -> a

opFixity1 :: Fixity1

opPrio :: Int

opToken :: String

Binary

A non-associative operator expecting two operands.

Fields

opSem2 :: a -> a -> a

opFixity2 :: Fixity2

opPrio :: Int

opToken :: String

Assoc

An infix associative operator that chains together many operands.

Fields

opSemN :: [a] -> a

opPrio :: Int

opToken :: String

data Fixity1

Fixity for unary operators.

Constructors

Prefix

The operator is written before its operand.

Postfix

The operator is written after its operand.

Instances

Enum Fixity1

Eq Fixity1

Show Fixity1

data Fixity2

Fixity for infix binary operators.

Constructors

InfixL

The operator associates to the left.

InfixR

The operator associates to the right.

Instances

Enum Fixity2

Eq Fixity2

Show Fixity2

isUnary :: Operator a -> Bool

isBinary :: Operator a -> Bool

isAssoc :: Operator a -> Bool

findOperator :: Monad m => String -> (Operator a -> Bool) -> [Operator a] -> m (Operator a)

findOperator name p os yields the operator from os that matches the predicate p and has token name. Fails if there are no or several matching operators.

Functions

data Function a

Representation of a function.

Constructors

Function

Fields

fnSem :: [a] -> a

fnName :: String

findFunction :: Monad m => String -> [Function a] -> m (Function a)

Yelds the function with the specified name. Fails if there are no or several matching functions.

function1 :: (a -> a) -> String -> Function a

Lifts a unary function to a Function.

function2 :: (a -> a -> a) -> String -> Function a

Lifts a binary function to a Function.