'DynFlag'-free version of 'mkParserFlags'
DynFlags is difficult, making using the lexer/parser
for pure parsing/lexing unreasonably difficult, even with
This is despite the fact that we only really need
* language extension flags * warning flags * a handful of boolean options
mkParserFlags' function makes is easier to directly construct a
ParserFlags. Furthermore, since
pExtsBitmap is just a footgun, I've gone
ahead and made
ParserFlags an abstract type.
Also, we now export
getBit instead of defining/exporting a
bunch of boilerplate functions that test for a particular 'ExtBits'.
In the process, I also
- cleaned up an unneeded special case for
UsePosPragsanother variant of
- made the logic in
reservedSymsFMmatch that of
Test Plan: make test
Reviewers: bgamari, alanz, tdammers
Subscribers: sjakobi, tdammers, rwbarton, mpickering, carter
GHC Trac Issues: #11301
Differential Revision: https://phabricator.haskell.org/D5405