DATA Mod
  | Mod         ref2nm			: {Ref2Nm}		-- inverse lookup of locally introduced binding RRef's
                moduleNm        : {HsName}
                moduleNr        : {Int}			-- sequence nr, index later into global table of modules
                stkDepth        : {Int}			-- max depth of stack for setting up globals
                binds           : {CRArray Bind}
                body			: Exp

DATA SExp
  -- base cases
  | Var         ref             : {RRef}
  | Int         int             : {Int}
  | Char        char            : {Char}
  | String      str             : {String}
  | Integer     integer         : {Integer}

DATA Exp
  -- base cases
  | SExp        sexpr           : SExp

  -- node constructor, tuple or data constructor, determined by tag
  | Tup         tag             : {CTag}
                args			: {CRArray Exp}

  -- let bindings, recursiveness allowed, yes/no eval made explicit in rhs of binding
  | Let         lev				: {Int}
  				firstOff		: {Int}			-- offset of first binding
  				ref2nm			: {Ref2Nm}		-- inverse lookup of locally introduced binding RRef's
                binds           : {CRArray Bind}
                body            : Exp

  -- application, abstraction
  | App         -- isTailRec		: {Bool}
  				func            : Exp
                args            : {CRArray Exp}
  | Lam         lev				: {Int}			-- lexical level
  				nrArgs          : {Int}			-- nr of arguments, 0 means it is a thunk
                nrBinds         : {Int}			-- nr stack frame locations to be allocated (excluding arguments) for locals
                stkDepth        : {Int}			-- max depth of stack
                ref2nm			: {Ref2Nm}		-- inverse lookup of locally introduced binding RRef's
                body            : Exp

  -- thunking, forcing, partial applications
  | Force		expr			: Exp
  -- | Thunk		expr			: Exp		-- expressed as parameterless Lam

  -- expr in a context to which must be returned (i.e. no tail rec)
  | Ret			expr			: Exp
  -- expr in a case alternative result context (with local bindings to be removed)
  | RetCase		nrBinds			: {Int}
  				expr			: Exp
  -- Tail context
  | Tail		expr			: Exp

  -- case
  | Case        expr            : SExp
                alts            : {CRArray Alt}

  -- FFI call
  | FFI         prim        	: {RunPrim}
                args			: {CRArray Exp}
{-
  | FFI         callconv        : {FFIWay}
                impEnt          : {ForeignEnt}
                ty              : {Ty}
                args			: {CRArray Exp}
-}

  -- Debug only
  | Dbg			msg				: {String}

DATA Alt
  | Alt         ref2nm			: {Ref2Nm}		-- inverse lookup of locally introduced binding RRef's
                pat             : Pat
                expr            : Exp

DATA Pat
  | Con         tag             : {CTag}
  | BoolExpr    expr            : Exp

SET AllNT
  = Mod SExp Exp Alt Pat