semantic/src/Data/AST.hs

{-# LANGUAGE DataKinds #-}
module Data.AST where

import Data.Range
import Data.Record
import Data.Span
import Data.Term
import Data.Aeson
import Data.Text (pack)
import Data.JSON.Fields

-- | An AST node labelled with symbols and source location.
type AST syntax grammar = Term syntax (Node grammar)

data Node grammar = Node
  { nodeSymbol    :: !grammar
  , nodeByteRange :: {-# UNPACK #-} !Range
  , nodeSpan      :: {-# UNPACK #-} !Span
  }
  deriving (Eq, Ord, Show)


instance Show grammar => ToJSONFields (Node grammar) where
  toJSONFields Node{..} =
    [ "symbol" .= pack (show nodeSymbol)
    , "span"   .= nodeSpan
    ]

-- | A location specified as possibly-empty intervals of bytes and line/column positions.
type Location = '[Range, Span]

nodeLocation :: Node grammar -> Record Location
nodeLocation Node{..} = nodeByteRange :. nodeSpan :. Nil