TypeLevelShow.Doc

Documentation

data Doc s

Simple pretty document ADT.

Designed to work on both type level (as a limited ErrorMessage) and term level (as a boring ADT).

Note that ShowType is magical (see compilerGHCCore/Type.hs#L1309), so we need to remove it for term level.

singletons-base defines a version of this, but retains the ShowType constructor and is in the singletons ecosystem.

Constructors

Text s

plain ol' text

(Doc s) :<>: (Doc s)

append docs next to each other

(Doc s) :$$: (Doc s)

stack docs on top of each other (newline)

Instances

Show s => Show (Doc s)

Defined in TypeLevelShow.Doc

Methods

showsPrec :: Int -> Doc s -> ShowS

show :: Doc s -> String

showList :: [Doc s] -> ShowS

type PDoc = Doc Symbol

Promoted Doc.

type family RenderDoc doc where ...

Render a PDoc as an ErrorMessage, for type-level error messages.

PDoc is a subset of ErrorMessage, so this is very boring.

Equations

RenderDoc (Text s) = Text s

RenderDoc (l :<>: r) = RenderDoc l :<>: RenderDoc r

RenderDoc (l :$$: r) = RenderDoc l :$$: RenderDoc r

class ReifyDoc (doc :: PDoc) where

Reify a promoted Doc to the corresponding term-level one.

Methods

reifyDoc :: Doc String

Instances

KnownSymbol s => ReifyDoc ('Text s)

Defined in TypeLevelShow.Doc

Methods

reifyDoc :: Doc String

(ReifyDoc l, ReifyDoc r) => ReifyDoc (l ':$$: r)

Defined in TypeLevelShow.Doc

Methods

reifyDoc :: Doc String

(ReifyDoc l, ReifyDoc r) => ReifyDoc (l ':<>: r)

Defined in TypeLevelShow.Doc

Methods

reifyDoc :: Doc String