QuickSpec.Term

This module is internal to QuickSpec.

Typed terms and operations on them.

Documentation

data a :+: b

A sum type. Intended to be used to build the type of function symbols. Comes with instances that are useful for QuickSpec.

Constructors

Inl a

Inr b

Instances

(Eq a, Eq b) => Eq (a :+: b)

Defined in QuickSpec.Term

Methods

(==) :: (a :+: b) -> (a :+: b) -> Bool

(/=) :: (a :+: b) -> (a :+: b) -> Bool

(Ord a, Ord b) => Ord (a :+: b)

Defined in QuickSpec.Term

Methods

compare :: (a :+: b) -> (a :+: b) -> Ordering

(<) :: (a :+: b) -> (a :+: b) -> Bool

(<=) :: (a :+: b) -> (a :+: b) -> Bool

(>) :: (a :+: b) -> (a :+: b) -> Bool

(>=) :: (a :+: b) -> (a :+: b) -> Bool

max :: (a :+: b) -> (a :+: b) -> a :+: b

min :: (a :+: b) -> (a :+: b) -> a :+: b

(Pretty fun1, Pretty fun2) => Pretty (fun1 :+: fun2)

Defined in QuickSpec.Term

Methods

pPrintPrec :: PrettyLevel -> Rational -> (fun1 :+: fun2) -> Doc

pPrint :: (fun1 :+: fun2) -> Doc

pPrintList :: PrettyLevel -> [fun1 :+: fun2] -> Doc

(Arity fun1, Arity fun2) => Arity (fun1 :+: fun2)

Defined in QuickSpec.Term

Methods

arity :: (fun1 :+: fun2) -> Int

(PrettyTerm fun1, PrettyTerm fun2) => PrettyTerm (fun1 :+: fun2)

Defined in QuickSpec.Term

Methods

termStyle :: (fun1 :+: fun2) -> TermStyle

(Typed fun1, Typed fun2) => Typed (fun1 :+: fun2)

Defined in QuickSpec.Term

Methods

typ :: (fun1 :+: fun2) -> Type

otherTypesDL :: (fun1 :+: fun2) -> DList Type

typeSubst_ :: (Var -> Builder TyCon) -> (fun1 :+: fun2) -> fun1 :+: fun2

(Sized fun1, Sized fun2) => Sized (fun1 :+: fun2)

Defined in QuickSpec.Term

Methods

size :: (fun1 :+: fun2) -> Int

newtype MeasureFuns f

A helper for Measure.

Constructors

MeasureFuns (Term f)

Instances

Ord f => Eq (MeasureFuns f)

Defined in QuickSpec.Term

Methods

(==) :: MeasureFuns f -> MeasureFuns f -> Bool

(/=) :: MeasureFuns f -> MeasureFuns f -> Bool

Ord f => Ord (MeasureFuns f)

Defined in QuickSpec.Term

Methods

compare :: MeasureFuns f -> MeasureFuns f -> Ordering

(<) :: MeasureFuns f -> MeasureFuns f -> Bool

(<=) :: MeasureFuns f -> MeasureFuns f -> Bool

(>) :: MeasureFuns f -> MeasureFuns f -> Bool

(>=) :: MeasureFuns f -> MeasureFuns f -> Bool

max :: MeasureFuns f -> MeasureFuns f -> MeasureFuns f

min :: MeasureFuns f -> MeasureFuns f -> MeasureFuns f

type Measure f = (Int, Int, Int, MeasureFuns f, Int, [Var])

A standard term ordering - size, skeleton, generality. Satisfies the property: if measure (schema t) < measure (schema u) then t < u.

class Sized a where

Methods

size :: a -> Int

Instances

Sized fun => Sized (Extended fun)

Defined in QuickSpec.Pruning.UntypedTwee

Methods

size :: Extended fun -> Int

Sized fun => Sized (Term fun)

Defined in QuickSpec.Pruning.UntypedTwee

Methods

size :: Term fun -> Int

Sized f => Sized (Term f)

Defined in QuickSpec.Term

Methods

size :: Term f -> Int

(Sized fun1, Sized fun2) => Sized (fun1 :+: fun2)

Defined in QuickSpec.Term

Methods

size :: (fun1 :+: fun2) -> Int

class Symbolic f a | a -> f where

A class for things that contain terms.

Methods

termsDL :: a -> DList (Term f)

A different list of all terms contained in the thing.

subst :: (Var -> Term f) -> a -> a

Apply a substitution to all terms in the thing.

Instances

Symbolic f a => Symbolic f [a]

Defined in QuickSpec.Term

Methods

termsDL :: [a] -> DList (Term f)

subst :: (Var -> Term f) -> [a] -> [a]

Symbolic f (Term f)

Defined in QuickSpec.Term

Methods

termsDL :: Term f -> DList (Term f)

subst :: (Var -> Term f) -> Term f -> Term f

data Var

A variable, which has a type and a number.

Constructors

V

Fields

• var_ty :: !Type
• var_id :: !Int

Instances

Eq Var

Defined in QuickSpec.Term

Methods

(==) :: Var -> Var -> Bool

(/=) :: Var -> Var -> Bool

Ord Var

Defined in QuickSpec.Term

Methods

compare :: Var -> Var -> Ordering

(<) :: Var -> Var -> Bool

(<=) :: Var -> Var -> Bool

(>) :: Var -> Var -> Bool

(>=) :: Var -> Var -> Bool

max :: Var -> Var -> Var

min :: Var -> Var -> Var

Show Var

Defined in QuickSpec.Term

Methods

showsPrec :: Int -> Var -> ShowS

show :: Var -> String

showList :: [Var] -> ShowS

Generic Var

Defined in QuickSpec.Term

Associated Types

type Rep Var :: Type -> Type

Methods

from :: Var -> Rep Var x

to :: Rep Var x -> Var

CoArbitrary Var

Defined in QuickSpec.Term

Methods

coarbitrary :: Var -> Gen b -> Gen b

Pretty Var

Defined in QuickSpec.Term

Methods

pPrintPrec :: PrettyLevel -> Rational -> Var -> Doc

pPrint :: Var -> Doc

pPrintList :: PrettyLevel -> [Var] -> Doc

Typed Var

Defined in QuickSpec.Term

Methods

typ :: Var -> Type

otherTypesDL :: Var -> DList Type

typeSubst_ :: (Var0 -> Builder TyCon) -> Var -> Var

type Rep Var

Defined in QuickSpec.Term

type Rep Var = D1 (MetaData "Var" "QuickSpec.Term" "quickspec-2.1.1-8ayCzcvVUjmFxcf6Z16wEZ" False) (C1 (MetaCons "V" PrefixI True) (S1 (MetaSel (Just "var_ty") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 Type) :*: S1 (MetaSel (Just "var_id") SourceUnpack SourceStrict DecidedStrict) (Rec0 Int)))

data Term f

A typed term.

Constructors

Var !Var

App !f ![Term f]

Instances

Functor Term

Defined in QuickSpec.Term

Methods

fmap :: (a -> b) -> Term a -> Term b

(<$) :: a -> Term b -> Term a

Symbolic f (Term f)

Defined in QuickSpec.Term

Methods

termsDL :: Term f -> DList (Term f)

subst :: (Var -> Term f) -> Term f -> Term f

Eq f => Eq (Term f)

Defined in QuickSpec.Term

Methods

(==) :: Term f -> Term f -> Bool

(/=) :: Term f -> Term f -> Bool

Ord f => Ord (Term f)

Defined in QuickSpec.Term

Methods

compare :: Term f -> Term f -> Ordering

(<) :: Term f -> Term f -> Bool

(<=) :: Term f -> Term f -> Bool

(>) :: Term f -> Term f -> Bool

(>=) :: Term f -> Term f -> Bool

max :: Term f -> Term f -> Term f

min :: Term f -> Term f -> Term f

Show f => Show (Term f)

Defined in QuickSpec.Term

Methods

showsPrec :: Int -> Term f -> ShowS

show :: Term f -> String

showList :: [Term f] -> ShowS

PrettyTerm f => Pretty (Term f)

Defined in QuickSpec.Term

Methods

pPrintPrec :: PrettyLevel -> Rational -> Term f -> Doc

pPrint :: Term f -> Doc

pPrintList :: PrettyLevel -> [Term f] -> Doc

Typed f => Typed (Term f)

Defined in QuickSpec.Term

Methods

typ :: Term f -> Type

otherTypesDL :: Term f -> DList Type

typeSubst_ :: (Var -> Builder TyCon) -> Term f -> Term f

Sized f => Sized (Term f)

Defined in QuickSpec.Term

Methods

size :: Term f -> Int

isApp :: Term f -> Bool

Is a term an application (i.e. not a variable)?

isVar :: Term f -> Bool

Is a term a variable?

terms :: Symbolic f a => a -> [Term f]

All terms contained in a Symbolic.

funs :: Symbolic f a => a -> [f]

All function symbols appearing in a Symbolic, in order of appearance, with duplicates included.

vars :: Symbolic f a => a -> [Var]

All variables appearing in a Symbolic, in order of appearance, with duplicates included.

freeVar :: Symbolic f a => a -> Int

Compute the number of a variable which does not appear in the Symbolic.

occ :: (Eq f, Symbolic f a) => f -> a -> Int

Count how many times a given function symbol occurs.

occVar :: Symbolic f a => Var -> a -> Int

Count how many times a given variable occurs.

mapVar :: (Var -> Var) -> Term f -> Term f

Map a function over variables.

subterms :: Term f -> [Term f]

Find all subterms of a term. Includes the term itself.

properSubterms :: Term f -> [Term f]

Find all subterms of a term. Does not include the term itself.

canonicalise :: Symbolic fun a => a -> a

Renames variables so that they appear in a canonical order. Also makes sure that variables of different types have different numbers.

evalTerm :: (Typed fun, Apply a, Monad m) => (Var -> m a) -> (fun -> m a) -> Term fun -> m a

Evaluate a term, given a valuation for variables and function symbols.

measure :: (Sized f, Typed f) => Term f -> Measure f

Compute the term ordering for a term.

compareFuns :: Ord f => Term f -> Term f -> Ordering

A helper for Measure.

class Pretty a where

Pretty printing class. The precedence level is used in a similar way as in the Show class. Minimal complete definition is either pPrintPrec or pPrint.

Minimal complete definition

pPrintPrec | pPrint

Methods

pPrintPrec :: PrettyLevel -> Rational -> a -> Doc

pPrint :: a -> Doc

pPrintList :: PrettyLevel -> [a] -> Doc

Instances

Pretty Bool

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> Bool -> Doc

pPrint :: Bool -> Doc

pPrintList :: PrettyLevel -> [Bool] -> Doc

Pretty Char

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> Char -> Doc

pPrint :: Char -> Doc

pPrintList :: PrettyLevel -> [Char] -> Doc

Pretty Double

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> Double -> Doc

pPrint :: Double -> Doc

pPrintList :: PrettyLevel -> [Double] -> Doc

Pretty Float

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> Float -> Doc

pPrint :: Float -> Doc

pPrintList :: PrettyLevel -> [Float] -> Doc

Pretty Int

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> Int -> Doc

pPrint :: Int -> Doc

pPrintList :: PrettyLevel -> [Int] -> Doc

Pretty Integer

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> Integer -> Doc

pPrint :: Integer -> Doc

pPrintList :: PrettyLevel -> [Integer] -> Doc

Pretty Ordering

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> Ordering -> Doc

pPrint :: Ordering -> Doc

pPrintList :: PrettyLevel -> [Ordering] -> Doc

Pretty ()

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> () -> Doc

pPrint :: () -> Doc

pPrintList :: PrettyLevel -> [()] -> Doc

Pretty Id

Defined in Twee.Base

Methods

pPrintPrec :: PrettyLevel -> Rational -> Id -> Doc

pPrint :: Id -> Doc

pPrintList :: PrettyLevel -> [Id] -> Doc

Pretty TyCon

Defined in QuickSpec.Type

Methods

pPrintPrec :: PrettyLevel -> Rational -> TyCon -> Doc

pPrint :: TyCon -> Doc

pPrintList :: PrettyLevel -> [TyCon] -> Doc

Pretty Var

Defined in QuickSpec.Term

Methods

pPrintPrec :: PrettyLevel -> Rational -> Var -> Doc

pPrint :: Var -> Doc

pPrintList :: PrettyLevel -> [Var] -> Doc

Pretty a => Pretty [a]

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> [a] -> Doc

pPrint :: [a] -> Doc

pPrintList :: PrettyLevel -> [[a]] -> Doc

Pretty a => Pretty (Maybe a)

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> Maybe a -> Doc

pPrint :: Maybe a -> Doc

pPrintList :: PrettyLevel -> [Maybe a] -> Doc

Function f => Pretty (Message f)

Defined in Twee

Methods

pPrintPrec :: PrettyLevel -> Rational -> Message f -> Doc

pPrint :: Message f -> Doc

pPrintList :: PrettyLevel -> [Message f] -> Doc

Function f => Pretty (Active f)

Defined in Twee

Methods

pPrintPrec :: PrettyLevel -> Rational -> Active f -> Doc

pPrint :: Active f -> Doc

pPrintList :: PrettyLevel -> [Active f] -> Doc

PrettyTerm f => Pretty (CriticalPair f)

Defined in Twee.CP

Methods

pPrintPrec :: PrettyLevel -> Rational -> CriticalPair f -> Doc

pPrint :: CriticalPair f -> Doc

pPrintList :: PrettyLevel -> [CriticalPair f] -> Doc

PrettyTerm f => Pretty (Rule f)

Defined in Twee.Rule

Methods

pPrintPrec :: PrettyLevel -> Rational -> Rule f -> Doc

pPrint :: Rule f -> Doc

pPrintList :: PrettyLevel -> [Rule f] -> Doc

Function f => Pretty (Reduction f)

Defined in Twee.Rule

Methods

pPrintPrec :: PrettyLevel -> Rational -> Reduction f -> Doc

pPrint :: Reduction f -> Doc

pPrintList :: PrettyLevel -> [Reduction f] -> Doc

Function f => Pretty (Resulting f)

Defined in Twee.Rule

Methods

pPrintPrec :: PrettyLevel -> Rational -> Resulting f -> Doc

pPrint :: Resulting f -> Doc

pPrintList :: PrettyLevel -> [Resulting f] -> Doc

Function f => Pretty (Proof f)

Defined in Twee.Proof

Methods

pPrintPrec :: PrettyLevel -> Rational -> Proof f -> Doc

pPrint :: Proof f -> Doc

pPrintList :: PrettyLevel -> [Proof f] -> Doc

PrettyTerm f => Pretty (Derivation f)

Defined in Twee.Proof

Methods

pPrintPrec :: PrettyLevel -> Rational -> Derivation f -> Doc

pPrint :: Derivation f -> Doc

pPrintList :: PrettyLevel -> [Derivation f] -> Doc

PrettyTerm f => Pretty (Lemma f)

Defined in Twee.Proof

Methods

pPrintPrec :: PrettyLevel -> Rational -> Lemma f -> Doc

pPrint :: Lemma f -> Doc

pPrintList :: PrettyLevel -> [Lemma f] -> Doc

PrettyTerm f => Pretty (Axiom f)

Defined in Twee.Proof

Methods

pPrintPrec :: PrettyLevel -> Rational -> Axiom f -> Doc

pPrint :: Axiom f -> Doc

pPrintList :: PrettyLevel -> [Axiom f] -> Doc

Function f => Pretty (Presentation f)

Defined in Twee.Proof

Methods

pPrintPrec :: PrettyLevel -> Rational -> Presentation f -> Doc

pPrint :: Presentation f -> Doc

pPrintList :: PrettyLevel -> [Presentation f] -> Doc

PrettyTerm f => Pretty (Equation f)

Defined in Twee.Equation

Methods

pPrintPrec :: PrettyLevel -> Rational -> Equation f -> Doc

pPrint :: Equation f -> Doc

pPrintList :: PrettyLevel -> [Equation f] -> Doc

Pretty f => Pretty (Extended f)

Defined in Twee.Base

Methods

pPrintPrec :: PrettyLevel -> Rational -> Extended f -> Doc

pPrint :: Extended f -> Doc

pPrintList :: PrettyLevel -> [Extended f] -> Doc

PrettyTerm f => Pretty (Atom f)

Defined in Twee.Constraints

Methods

pPrintPrec :: PrettyLevel -> Rational -> Atom f -> Doc

pPrint :: Atom f -> Doc

pPrintList :: PrettyLevel -> [Atom f] -> Doc

PrettyTerm f => Pretty (Formula f)

Defined in Twee.Constraints

Methods

pPrintPrec :: PrettyLevel -> Rational -> Formula f -> Doc

pPrint :: Formula f -> Doc

pPrintList :: PrettyLevel -> [Formula f] -> Doc

PrettyTerm f => Pretty (Branch f)

Defined in Twee.Constraints

Methods

pPrintPrec :: PrettyLevel -> Rational -> Branch f -> Doc

pPrint :: Branch f -> Doc

pPrintList :: PrettyLevel -> [Branch f] -> Doc

PrettyTerm f => Pretty (Model f)

Defined in Twee.Constraints

Methods

pPrintPrec :: PrettyLevel -> Rational -> Model f -> Doc

pPrint :: Model f -> Doc

pPrintList :: PrettyLevel -> [Model f] -> Doc

Pretty a => Pretty (Poly a)

Defined in QuickSpec.Type

Methods

pPrintPrec :: PrettyLevel -> Rational -> Poly a -> Doc

pPrint :: Poly a -> Doc

pPrintList :: PrettyLevel -> [Poly a] -> Doc

PrettyTerm f => Pretty (Term f)

Defined in QuickSpec.Term

Methods

pPrintPrec :: PrettyLevel -> Rational -> Term f -> Doc

pPrint :: Term f -> Doc

pPrintList :: PrettyLevel -> [Term f] -> Doc

(Pretty a, Pretty b) => Pretty (Either a b)

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> Either a b -> Doc

pPrint :: Either a b -> Doc

pPrintList :: PrettyLevel -> [Either a b] -> Doc

(Pretty a, Pretty b) => Pretty (a, b)

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> (a, b) -> Doc

pPrint :: (a, b) -> Doc

pPrintList :: PrettyLevel -> [(a, b)] -> Doc

(Pretty fun1, Pretty fun2) => Pretty (fun1 :+: fun2)

Defined in QuickSpec.Term

Methods

pPrintPrec :: PrettyLevel -> Rational -> (fun1 :+: fun2) -> Doc

pPrint :: (fun1 :+: fun2) -> Doc

pPrintList :: PrettyLevel -> [fun1 :+: fun2] -> Doc

(Pretty a, Pretty b, Pretty c) => Pretty (a, b, c)

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> (a, b, c) -> Doc

pPrint :: (a, b, c) -> Doc

pPrintList :: PrettyLevel -> [(a, b, c)] -> Doc

(Pretty a, Pretty b, Pretty c, Pretty d) => Pretty (a, b, c, d)

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> (a, b, c, d) -> Doc

pPrint :: (a, b, c, d) -> Doc

pPrintList :: PrettyLevel -> [(a, b, c, d)] -> Doc

(Pretty a, Pretty b, Pretty c, Pretty d, Pretty e) => Pretty (a, b, c, d, e)

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> (a, b, c, d, e) -> Doc

pPrint :: (a, b, c, d, e) -> Doc

pPrintList :: PrettyLevel -> [(a, b, c, d, e)] -> Doc

(Pretty a, Pretty b, Pretty c, Pretty d, Pretty e, Pretty f) => Pretty (a, b, c, d, e, f)

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> (a, b, c, d, e, f) -> Doc

pPrint :: (a, b, c, d, e, f) -> Doc

pPrintList :: PrettyLevel -> [(a, b, c, d, e, f)] -> Doc

(Pretty a, Pretty b, Pretty c, Pretty d, Pretty e, Pretty f, Pretty g) => Pretty (a, b, c, d, e, f, g)

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> (a, b, c, d, e, f, g) -> Doc

pPrint :: (a, b, c, d, e, f, g) -> Doc

pPrintList :: PrettyLevel -> [(a, b, c, d, e, f, g)] -> Doc

(Pretty a, Pretty b, Pretty c, Pretty d, Pretty e, Pretty f, Pretty g, Pretty h) => Pretty (a, b, c, d, e, f, g, h)

Defined in Text.PrettyPrint.HughesPJClass

Methods

pPrintPrec :: PrettyLevel -> Rational -> (a, b, c, d, e, f, g, h) -> Doc

pPrint :: (a, b, c, d, e, f, g, h) -> Doc

pPrintList :: PrettyLevel -> [(a, b, c, d, e, f, g, h)] -> Doc

class Arity f where

For types which have a notion of arity.

Methods

arity :: f -> Int

Measure the arity.

Instances

Arity f => Arity (Extended f)

Defined in Twee.Base

Methods

arity :: Extended f -> Int

Arity f => Arity (Fun f)

Defined in Twee.Base

Methods

arity :: Fun f -> Int

(Arity fun1, Arity fun2) => Arity (fun1 :+: fun2)

Defined in QuickSpec.Term

Methods

arity :: (fun1 :+: fun2) -> Int

class EqualsBonus f

A hack for encoding Horn clauses. See Score. The default implementation of hasEqualsBonus should work OK.

Instances

EqualsBonus f => EqualsBonus (Extended f)

Defined in Twee.Base

Methods

hasEqualsBonus :: Extended f -> Bool

isEquals :: Extended f -> Bool

isTrue :: Extended f -> Bool

isFalse :: Extended f -> Bool

EqualsBonus f => EqualsBonus (Fun f)

Defined in Twee.Base

Methods

hasEqualsBonus :: Fun f -> Bool

isEquals :: Fun f -> Bool

isTrue :: Fun f -> Bool

isFalse :: Fun f -> Bool

prettyPrint :: Pretty a => a -> IO ()

Print a value to the console.

class Pretty f => PrettyTerm f where

A class for customising the printing of function symbols.

Minimal complete definition

Nothing

Methods

termStyle :: f -> TermStyle

The style of the function symbol. Defaults to curried.

Instances

PrettyTerm TyCon

Defined in QuickSpec.Type

Methods

termStyle :: TyCon -> TermStyle

PrettyTerm f => PrettyTerm (Extended f)

Defined in Twee.Base

Methods

termStyle :: Extended f -> TermStyle

PrettyTerm f => PrettyTerm (Fun f)

Defined in Twee.Pretty

Methods

termStyle :: Fun f -> TermStyle

(PrettyTerm fun1, PrettyTerm fun2) => PrettyTerm (fun1 :+: fun2)

Defined in QuickSpec.Term

Methods

termStyle :: (fun1 :+: fun2) -> TermStyle

newtype TermStyle

Defines how to print out a function symbol.

Constructors

TermStyle

Fields

• pPrintTerm :: forall a. Pretty a => PrettyLevel -> Rational -> Doc -> [a] -> Doc

  Renders a function application. Takes the following arguments in this order: Pretty-printing level, current precedence, pretty-printed function symbol and list of arguments to the function.

module Twee.Pretty