WIP: Qualified fortran version

[smoothdeveloper]

I'm starting work to allow having CompilerOption list to describe the introduced QualifiedFortranVersion, which will enable supporting DecStructure option.

Looking for maintainers feedback if this is right approach?

As of now, I'd like to get things to work back, which should be done by adjusting Parser.hs and maybe some more things in Main.hs, and later revise the new symbol names, which right now, may not be what we ultimately want.

If a maintainer want to look at the remaining type check error and suggest the right approach, as it is not clear to me at this stage.

Once this compile, I have a bit more work in the lexer to also have the TRecord token and maybe other things.

todo:

• structure / endstructure in the lexer
• record declaration in the lexer
• non standard attributes in the lexer[allocate]
• . field access in the lexer
• figuring out the rest

related: #303

[smoothdeveloper]

Ok, I succeeded in flowing the entry point options down to the parsers, now I'm facing some challenge to understand what I should do in the free form lexer, to support the /MyStructName/ that comes right after the structure keyword.

In the fixed form lexer I see:

fortran-src/src/Language/Fortran/Parser/Fixed/Lexer.x

Line 232 in b8a490f

<st,iif> "/" { addSpan TSlash }

and the free form lexer:

fortran-src/src/Language/Fortran/Parser/Free/Lexer.x

Line 319 in b8a490f

<scN> "/" { slashOrDivision }

fortran-src/src/Language/Fortran/Parser/Free/Lexer.x

Lines 694 to 699 in b8a490f

	slashOrDivision :: LexAction (Maybe Token)
	slashOrDivision = do
	context <- topContext
	case context of
	ConData -> addSpan TSlash
	_ -> addSpan TOpDivision

I'm unsure how to proceed, when I've parsed structure should I change context so as to process the "/" differently?

I'd assume this flow:

[TStructure, TSlash, TId "MyStructName", TSlash, ...]

What do those contexts mean:

fortran-src/src/Language/Fortran/Parser/Monad.hs

Lines 33 to 40 in b8a490f

	data Context =
	ConStart
	| ConData
	| ConImplicit
	| ConNamelist
	| ConCommon
	deriving (Show, Eq)

I'll look more at this test and try to add one for free form:

fortran-src/test/Language/Fortran/Parser/Fixed/LexerSpec.hs

Lines 270 to 274 in b8a490f

	resetSrcSpan (collectFixedTokens' Fortran77Legacy src)
	`shouldBe` resetSrcSpan [ TStructure u, TSlash u, TId u "foo", TSlash u, TNewline u
	, TUnion u, TNewline u
	, TMap u, TNewline u
	, TType u "integer", TId u "i", TNewline u

[smoothdeveloper]

Wondering if we want to separate the QualifiedFortranVersion, which changes a bunch of signatures for the "already instanciated parsers" and the rest of the change I started working on (supporting option in QualifiedFortranVersion to parse the structure / record declarations in >= Fortran 90).