Safe Haskell	Safe-Inferred
Language	Haskell2010

Silkscreen.Precedence

Contents

Printing with precedence
Re-exports

Synopsis

class Printer p => PrecedencePrinter p where
- type Level p
- askingPrec :: (Level p -> p) -> p
- localPrec :: (Level p -> Level p) -> p -> p
setPrec :: PrecedencePrinter p => Level p -> p -> p
prec :: (PrecedencePrinter p, Ord (Level p)) => Level p -> p -> p
assoc :: (PrecedencePrinter p, Ord (Level p)) => Level p -> (p -> p -> p) -> p -> p -> p
nonAssoc :: (PrecedencePrinter p, Ord (Level p)) => Level p -> Level p -> (p -> p -> p) -> p -> p -> p
leftAssoc :: (PrecedencePrinter p, Ord (Level p)) => Level p -> Level p -> (p -> p -> p) -> p -> p -> p
rightAssoc :: (PrecedencePrinter p, Ord (Level p)) => Level p -> Level p -> (p -> p -> p) -> p -> p -> p
infix_ :: (PrecedencePrinter p, Ord (Level p)) => Level p -> (p -> p) -> (p -> p) -> (p -> p -> p) -> p -> p -> p
module Silkscreen

Printing with precedence

class Printer p => PrecedencePrinter p where Source #

Pretty-printing with parenthesis insertion resolving precedence.

Given:

data ArithLevel = Bottom | Add | Mult | Exp | Top
  deriving (Eq, Ord)

(+.) :: (PrecedencePrinter p, Level p ~ ArithLevel) => p -> p -> p
(+.) = assoc Add (surround (pretty " + "))
infixl 6 +.

(*.) :: (PrecedencePrinter p, Level p ~ ArithLevel) => p -> p -> p
(*.) = assoc Mult (surround (pretty " * "))
infixl 7 *.

(^.) :: (PrecedencePrinter p, Level p ~ ArithLevel) => p -> p -> p
(^.) = rightAssoc Exp Top (surround (pretty " ^ "))
infixr 8 ^.

>>> putDoc . runPrec Bottom $ ('pretty' "a" +. 'pretty' "b") *. 'pretty' "c" ^. ('pretty' "d" *. 'pretty' "e")
(a + b) * c ^ (d * e)

Associated Types

type Level p Source #

The type used to represent precedence levels. This is defined as an associated type so that consumers can use e.g. symbolic representations of their DSL’s precedence levels instead of e.g. unsemantic Ints.

This type will usually be Ordered, but this isn’t strictly required so that other means of determining precedence can be provided.

Methods

askingPrec :: (Level p -> p) -> p Source #

Print informed by the current Level.

localPrec :: (Level p -> Level p) -> p -> p Source #

Locally change the Level in a printer.

Instances

Instances details

PrecedencePrinter p => PrecedencePrinter (Rainbow p) Source #
Instance details Defined in Silkscreen.Printer.Rainbow Associated Types type Level (Rainbow p) Source # Methods askingPrec :: (Level (Rainbow p) -> Rainbow p) -> Rainbow p Source # localPrec :: (Level (Rainbow p) -> Level (Rainbow p)) -> Rainbow p -> Rainbow p Source #
PrecedencePrinter b => PrecedencePrinter (a -> b) Source #
Instance details Defined in Silkscreen.Precedence Associated Types type Level (a -> b) Source # Methods askingPrec :: (Level (a -> b) -> a -> b) -> a -> b Source # localPrec :: (Level (a -> b) -> Level (a -> b)) -> (a -> b) -> a -> b Source #
(Bounded level, Printer a) => PrecedencePrinter (Prec level a) Source #
Instance details Defined in Silkscreen.Printer.Prec Associated Types type Level (Prec level a) Source # Methods askingPrec :: (Level (Prec level a) -> Prec level a) -> Prec level a Source # localPrec :: (Level (Prec level a) -> Level (Prec level a)) -> Prec level a -> Prec level a Source #

setPrec :: PrecedencePrinter p => Level p -> p -> p Source #

Set a constant precedence.

This function does not insert parentheses, and thus should be used when inserting parentheses or otherwise resetting the precedence level.

prec :: (PrecedencePrinter p, Ord (Level p)) => Level p -> p -> p Source #

Set a constant precedence, parenthesizing in higher-precedence contexts.

assoc :: (PrecedencePrinter p, Ord (Level p)) => Level p -> (p -> p -> p) -> p -> p -> p Source #

Make an associative infix combinator at the given level.

nonAssoc :: (PrecedencePrinter p, Ord (Level p)) => Level p -> Level p -> (p -> p -> p) -> p -> p -> p Source #

Make a non-associative infix combinator at the given levels for the operator itself and its operands.

leftAssoc :: (PrecedencePrinter p, Ord (Level p)) => Level p -> Level p -> (p -> p -> p) -> p -> p -> p Source #

Make a left-associative infix combinator at the given levels for the operator itself and its right operand.

rightAssoc :: (PrecedencePrinter p, Ord (Level p)) => Level p -> Level p -> (p -> p -> p) -> p -> p -> p Source #

Make a right-associative infix combinator at the given levels for the operator itself and its left operand.

infix_ :: (PrecedencePrinter p, Ord (Level p)) => Level p -> (p -> p) -> (p -> p) -> (p -> p -> p) -> p -> p -> p Source #

Make an infix combinator at the given level for the operator itself, applying functions to either operand.

Re-exports

module Silkscreen