AbsSyn.ag

DATA TyAGItf
  | AGItf       relevTy         : RelevTy

DATA QualAGItf
  | AGItf       relevQual       : RelevQual

DATA CoeAGItf
  | AGItf       relevCoe        : RelevCoe

DATA AnaEval
  -- variable, for propagation
  | Var         av				: {UID}

  -- evaluated (Bot)
  | WHNF

  -- unknown (Top)
  | Lazy

  -- meet & join are explicitly encoded because of delayed or impossible simplification
  | Meet		opnds			: AnaEvalL
  | Join		opnds			: AnaEvalL

TYPE AnaEvalL	=	[AnaEval]

SET AllAna 		= 	AnaEval AnaEvalL

DATA RelevCoe
  -- no coercion
  | Id

  -- err coercion
  | Err			str				: String

  -- composition of coercion
  | Comp		l				: RelevCoe
  				r				: RelevCoe

  -- coercion for function
  | Fun 		args			: RelevCoeL
  				res				: RelevCoe

  -- coercion going in the 'wrong' direction of lattice, delegating the corresponding 'cast' to the outside
  | Cast		coe 			: RelevCoe

  -- coercion casting between types
  | CastTy		l	 			: RelevTy
  				r				: RelevTy

  -- the real coercion, for each Ana lattice, may require substitutions later on
  | Eval		from			: AnaEval
  				to				: AnaEval

TYPE RelevCoeL	=	[RelevCoe]

SET AllCoe		=	RelevCoe RelevCoeL

DATA RelevQual
  -- less than or equal in AnaEval lattice
  | SubEval		l				: AnaEval
  				r				: AnaEval

TYPE RelevQualL	=	[RelevQual]

DATA RelevTy
  -- no ty (for now)
  | None
  -- error ty (for now)
  | Err			str				: String

  -- analysis info is base case of ty
  | Ana         eval			: AnaEval
  				-- put others here

  -- function structure
  | Fun			quant			: {RQuant}
  				quants			: {[UID]}
  				quals			: RelevQualL
  				args			: RelevTyL
  				res				: RelevTy

TYPE RelevTyL	=	[RelevTy]
TYPE MbRelevTy	=	MAYBE RelevTy

SET AllRelevTy	=	RelevTy RelevTyL MbRelevTy RelevQual RelevQualL

SET AllNT = AllRelevTy AllAna AllCoe