GroteTrap-0.5.2: Parser and selection library for expression languages.

Safe HaskellSafe





type Pos = Int Source #

A Pos is a position in between two elements in a list. For example, position 0 marks the beginning of the list, and position length list marks the end of the list. There are n + 1 valid positions for a list of length n.

type Range = (Pos, Pos) Source #

A range's positions mark the begin and end of a sublist, respectively.

class Ranged a where Source #

Something that knows its range as sublist in a larger list. Minimal complete definition: either range or both begin and end.


range :: a -> Range Source #

Yields the element's range.

begin :: a -> Pos Source #

Yields the element's begin position.

end :: a -> Pos Source #

Yields the element's end position.

Utility functions

distRange :: Range -> Range -> Int Source #

distRange (b1, e1) (b2, e2) is defined as |b1 - b2| + |e1 - e2|.

inRange :: Pos -> Range -> Bool Source #

Whether a position falls within a range, including the range's edges.

includes :: Range -> Range -> Bool Source #

Yields whether the second argument completely falls within the first argument.

unionRange :: Range -> Range -> Range Source #

unionRange x y yields the smallest range z such that x `includes` z and y `includes` z.

size :: Range -> Int Source #

A range's size is the number of elements it contains.

validRange :: Range -> Bool Source #

A range is valid if its positions are nonnegative and begin < end.