Types.hs

module Boilerplate.Types where

import Data.Map.Strict (Map)
import Data.Text (Text)

-- `BOILERPLATE ... BOILERPLATE END`
data Marker = Marker Text Int (Maybe Int) -- ^^ config (start position) (end position)
  deriving (Eq, Show)

-- line, col (1-indexed)
data Pos = Pos Int Int
  deriving (Eq, Ord, Show)

data Comment = Comment Text Pos Pos -- text start end
  deriving (Eq, Show)

data Config = Config Text [Text] [(Text, Custom)] -- ^^ type [rule] [custom key, value]
            | ConfigStart
            | ConfigEnd
  deriving (Eq, Show)
-- TODO (Text, Custom) could have a namespace

data Custom = Global Text -- ^^ available anywhere
            | Indexed [Text] -- ^^ applies to ordered product fields
            | Named (Map Text Text) -- ^^ applies to record fields and data constructors
            | NamedIndexed (Map Text [Text]) -- ^^ applies to ordered fields inside a sum type
  deriving (Eq, Show)

data Type = ProductType Text [Text] Text [Text]  -- ^^ type tparams cons [param types]
          | RecordType Text [Text] Text [(Text, Text)] -- ^^ type tparams cons [(fieldname, param type)]
          | SumType Text [Text] [(Text, [Text])] -- ^^ type tparams [(cons, param types)] (no records)
  deriving (Eq, Show)

type Tree = [Atom]

newtype Rule = Rule Tree
  deriving (Eq, Show)

-- TODO a lot of Text locations could be Tree: convert on demand
data Atom =
    Raw Text
  | Type
  | TParams Tree Tree Tree Text Text -- ^^ empty prefix elem sep suffix
  | TParam
  | Product Tree -- ^^ elem
  | Sum Text Tree Text Text -- ^^ prefix elem sep suffix
  | Uncons Int -- ^^ id
  | Cons
  | Field Tree Tree Tree Text Text -- ^^ empty prefix elem sep suffix
  | Param Int -- ^^ id
  | FieldName
  | FieldType
  | Custom Text (Maybe Tree) -- ^^ name fallback
  | Sugar Sugar
    deriving (Eq, Show)

data Sugar = Instance Text
  deriving (Eq, Show)

-- FIXME support for iterating parameters with free type params (in the
--      interpreter, filter fields by the type name and only include things with
--      a type parameter), e.g. Foldable.
--
-- TODO syntax sugar for a strict subset with semantics of Divisible, Decidable,
--      Applicative, Alt