Question

parseSource :: String -> Either ParserError Mod.Module
parseSource src = do
    (imports, rest) <- parseImports (Lex.lexSource src)
    bindings <- mapM parseBinding rest
    buildModule imports bindings

I need to make the above return an IO (Either ParserError Mod.Module) as the buildModule statement at the end will need to perform some IO functions (reading files). The problem i have is that when i make it an IO function, i can no longer do the bind(wrong term?) <- operations.

What is the simplest way to make this work?

Answer 1

Take a look at defining your problem in terms of ErrorT ParseError IO.