Penny.Liberty.Expressions

Documentation

newtype Precedence

Precedence can be any integer; the greater the number, the higher the precedence.

Constructors

Precedence Int

Instances

Eq Precedence

Ord Precedence

Show Precedence

data Associativity

Constructors

ALeft

ARight

Instances

Show Associativity

data Token a

Constructors

TokOperand a

TokUnaryPostfix (a -> a)

TokUnaryPrefix Precedence (a -> a)

TokBinary Precedence Associativity (a -> a -> a)

TokOpenParen

TokCloseParen

Instances

Show a => Show (Token a)

newtype Operand a

An operand; for example, in the expression 5 4 +, 5 and 4 are operands.

Constructors

Operand a

Instances

Show a => Show (Operand a)

tokAnd :: Token (a -> Bool)

An And token which is left associative with precedence 3.

tokOr :: Token (a -> Bool)

An Or token which is left associative with precedence 2.

tokNot :: Token (a -> Bool)

A unary prefix Not token with precedence 4.

evaluate :: Foldable l => l (Token a) -> Maybe a

Tokens should be enqueued from left to right, so that tokens on the left side of the sequence are those at the beginning of the expression.