Safe Haskell	None
Language	Haskell98

Control.PatternArrows

Description

Arrows for Pretty Printing

Synopsis

Documentation

newtype Pattern u a b #

A first-order pattern match

A pattern is a Kleisli arrow for the StateT Maybe monad. That is, patterns can fail, and can carry user-defined state.

Constructors

Pattern
Fields runPattern :: Kleisli (StateT u Maybe) a b

Instances

Arrow (Pattern u) #
Methods arr :: (b -> c) -> Pattern u b c # first :: Pattern u b c -> Pattern u (b, d) (c, d) # second :: Pattern u b c -> Pattern u (d, b) (d, c) # (***) :: Pattern u b c -> Pattern u b' c' -> Pattern u (b, b') (c, c') # (&&&) :: Pattern u b c -> Pattern u b c' -> Pattern u b (c, c') #
ArrowZero (Pattern u) #
Methods zeroArrow :: Pattern u b c #
ArrowPlus (Pattern u) #
Methods (<+>) :: Pattern u b c -> Pattern u b c -> Pattern u b c #
Category * (Pattern u) #
Methods id :: cat a a # (.) :: cat b c -> cat a b -> cat a c #
Functor (Pattern u a) #
Methods fmap :: (a -> b) -> Pattern u a a -> Pattern u a b # (<$) :: a -> Pattern u a b -> Pattern u a a #

pattern :: Pattern u a b -> u -> a -> Maybe b #

Run a pattern with an input and initial user state

Returns Nothing if the pattern fails to match

mkPattern :: (a -> Maybe b) -> Pattern u a b #

Construct a pattern from a function

Construct a pattern from a stateful function

chainl :: Pattern u a (a, a) -> (r -> r -> r) -> Pattern u a r -> Pattern u a r #

Construct a pattern which recursively matches on the left-hand-side

chainr :: Pattern u a (a, a) -> (r -> r -> r) -> Pattern u a r -> Pattern u a r #

Construct a pattern which recursively matches on the right-hand side

wrap :: Pattern u a (s, a) -> (s -> r -> r) -> Pattern u a r -> Pattern u a r #

Construct a pattern which recursively matches on one-side of a tuple

split :: Pattern u a (s, t) -> (s -> t -> r) -> Pattern u a r #

Construct a pattern which matches a part of a tuple

A table of operators

Constructors

OperatorTable
Fields runOperatorTable :: [[Operator u a r]]

data Operator u a r where #

An operator:

AssocL: A left-associative operator
AssocR: A right-associative operator
Wrap: A prefix-like or postfix-like operator
Split: A prefix-like or postfix-like operator which does not recurse into its operand

Constructors

AssocL :: Pattern u a (a, a) -> (r -> r -> r) -> Operator u a r
AssocR :: Pattern u a (a, a) -> (r -> r -> r) -> Operator u a r
Wrap :: Pattern u a (s, a) -> (s -> r -> r) -> Operator u a r
Split :: Pattern u a (s, t) -> (s -> t -> r) -> Operator u a r

Build a pretty printer from an operator table and an indecomposable pattern