Lib2.hs

{-# OPTIONS_GHC -Wno-unused-top-binds #-}

module Lib2
  ( parseStatement,
    executeStatement,
    ParsedStatement
  )
where

import DataFrame (DataFrame)
import InMemoryTables (TableName)

type ErrorMessage = String
type Database = [(TableName, DataFrame)]

-- Keep the type, modify constructors
data ParsedStatement = ParsedStatement

-- Parses user input into an entity representing a parsed
-- statement
parseStatement :: String -> Either ErrorMessage ParsedStatement
parseStatement _ = Left "Not implemented: parseStatement"

-- Executes a parsed statemet. Produces a DataFrame. Uses
-- InMemoryTables.databases a source of data.
executeStatement :: ParsedStatement -> Either ErrorMessage DataFrame
executeStatement _ = Left "Not implemented: executeStatement"