555 lines
16 KiB
Ada
555 lines
16 KiB
Ada
separate (H2.Scheme.Execute)
|
|
|
|
procedure Evaluate is
|
|
pragma Inline (Evaluate);
|
|
|
|
Operand: aliased Object_Pointer;
|
|
Car: aliased Object_Pointer;
|
|
Cdr: aliased Object_Pointer;
|
|
|
|
generic
|
|
V: Object_Pointer;
|
|
Opcode: Opcode_Type;
|
|
procedure Generic_And_Or_Syntax;
|
|
|
|
procedure Generic_And_Or_Syntax is
|
|
begin
|
|
-- (and <test1> <test2> ...)
|
|
-- (and (= 2 2) (> 2 1)) ==> #t
|
|
-- (and (= 2 2) (< 2 1)) ==> #f
|
|
-- (and (= 2 2) (< 2 1) (= 3 3)) ==> #f
|
|
-- (and 1 2 'c '(f g)) ==> (f g)
|
|
-- (and) ==> #t
|
|
|
|
Operand := Cdr; -- Skip "And"
|
|
if Operand = Nil_Pointer then
|
|
-- (and)
|
|
Pop_Frame (Interp);
|
|
Chain_Frame_Result (Interp, Interp.Stack, V);
|
|
elsif not Is_Cons(Operand) or else Get_Last_Cdr(Operand) /= Nil_Pointer then
|
|
-- (and . 10)
|
|
-- (and 1 2 . 10)
|
|
Ada.Text_IO.Put_LINE ("FUCKING cDR FOR DEFINE");
|
|
raise Syntax_Error;
|
|
else
|
|
Set_Frame_Opcode (Interp.Stack, Opcode);
|
|
Set_Frame_Operand (Interp.Stack, Get_Cdr(Operand)); -- <test2> onwards
|
|
Clear_Frame_Result (Interp.Stack);
|
|
|
|
-- arrange to evaluate <test1>
|
|
Push_Frame (Interp, Opcode_Evaluate_Object, Get_Car(Operand));
|
|
end if;
|
|
end Generic_And_Or_Syntax;
|
|
|
|
procedure Evaluate_And_Syntax is new Generic_And_Or_Syntax(True_Pointer, Opcode_Finish_And_Syntax);
|
|
procedure Evaluate_Or_Syntax is new Generic_And_Or_Syntax(False_Pointer, Opcode_Finish_Or_Syntax);
|
|
|
|
procedure Evaluate_Define_Syntax is
|
|
pragma Inline (Evaluate_Define_Syntax);
|
|
begin
|
|
-- TODO: limit the context where define can be used.
|
|
|
|
-- (define x 10)
|
|
-- (define (add x y) (+ x y)) -> (define add (lambda (x y) (+ x y)))
|
|
Operand := Cdr; -- Skip "define"
|
|
|
|
if not Is_Cons(Operand) or else not Is_Cons(Get_Cdr(Operand)) then
|
|
-- e.g) (define)
|
|
-- (define . 10)
|
|
-- (define x . 10)
|
|
Ada.Text_IO.Put_LINE ("TOO FEW ARGUMENTS FOR DEFINE");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
Car := Get_Car(Operand);
|
|
Cdr := Get_Cdr(Operand);
|
|
if Is_Cons(Car) then
|
|
-- define a function: (define (add x y) ...)
|
|
null;
|
|
elsif Is_Symbol(Car) then
|
|
-- define a symbol: (define x ...)
|
|
if Get_Cdr(Cdr) /= Nil_Pointer then
|
|
Ada.Text_IO.Put_LINE ("TOO MANY ARGUMENTS FOR DEFINE");
|
|
raise Syntax_Error;
|
|
end if;
|
|
Cdr := Get_Car(Cdr); -- Value
|
|
|
|
-- Arrange to finish defining after value evaluation.
|
|
Set_Frame_Opcode (Interp.Stack, Opcode_Finish_Define_Symbol);
|
|
Set_Frame_Operand (Interp.Stack, Car);
|
|
|
|
-- Arrange to evalaute the value part
|
|
Push_Frame (Interp, Opcode_Evaluate_Object, Cdr);
|
|
else
|
|
Ada.Text_IO.Put_LINE ("NO SYMBOL NOR ARGUMENT LIST AFTER DEFINE");
|
|
raise Syntax_Error;
|
|
end if;
|
|
end Evaluate_Define_Syntax;
|
|
|
|
procedure Evaluate_If_Syntax is
|
|
pragma Inline (Evaluate_If_Syntax);
|
|
begin
|
|
-- (if <test> <consequent>)
|
|
-- (if <test> <consequent> <alternate>)
|
|
-- e.g) (if (> 3 2) 'yes)
|
|
-- (if (> 3 2) 'yes 'no)
|
|
-- (if (> 3 2) (- 3 2) (+ 3 2))
|
|
Operand := Cdr; -- Skip "if"
|
|
if Not Is_Cons(Operand) then
|
|
-- e.g) (if)
|
|
-- (if . 10)
|
|
Ada.Text_IO.Put_LINE ("NO CONDITIONAL FOR IF");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
Car := Get_Car(Operand); -- <test>
|
|
|
|
Operand := Get_Cdr(Operand); -- cons cell containg <consequent>
|
|
if not Is_Cons(Operand) then
|
|
Ada.Text_IO.Put_Line ("NO ACTION FOR IF");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
Cdr := Get_Cdr(Operand); -- cons cell containing <alternate>
|
|
if Cdr = Nil_Pointer then
|
|
-- no <alternate>. it's ok
|
|
Ada.Text_IO.Put_Line ("NO ALTERNATE");
|
|
null;
|
|
elsif not Is_Cons(Cdr) then
|
|
-- no <alternate> but reduncant cdr.
|
|
-- (if (> 3 2) 3 . 99)
|
|
Ada.Text_IO.Put_Line ("FUCKING CDR FOR IF");
|
|
raise Syntax_Error;
|
|
|
|
elsif Get_Cdr(Cdr) /= Nil_Pointer then
|
|
-- (if (> 3 2) 3 2 . 99)
|
|
-- (if (> 3 2) 3 2 99)
|
|
Ada.Text_IO.Put_Line ("TOO MANY ARGUMENTS FOR IF");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
-- Switch the current frame to execute action after <test> evaluation.
|
|
Set_Frame_Opcode (Interp.Stack, Opcode_Finish_If_Syntax);
|
|
Set_Frame_Operand (Interp.Stack, Operand);
|
|
|
|
-- Arrange to evalaute the conditional
|
|
Push_Frame (Interp, Opcode_Evaluate_Object, Car);
|
|
|
|
end Evaluate_If_Syntax;
|
|
|
|
procedure Evaluate_Lambda_Syntax is
|
|
pragma Inline (Evaluate_Lambda_Syntax);
|
|
begin
|
|
-- (lambda <formals> <body>)
|
|
-- e.g) (lambda (x y) (+ x y))
|
|
-- e.g) (lambda (x y . z) z)
|
|
-- e.g) (lambda x (car x))
|
|
Operand := Cdr; -- Skip "lambda". cons cell pointing to <formals>
|
|
if not Is_Cons(Operand) then
|
|
-- e.g) (lambda)
|
|
-- (lambda . 10)
|
|
Ada.Text_IO.Put_LINE ("FUCKNING CDR FOR LAMBDA");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
Car := Get_Car(Operand); -- <formals>
|
|
if Car = Nil_Pointer or else Is_Symbol(Car) then
|
|
-- (lambda () ...) or (lambda x ...)
|
|
-- nothing to do
|
|
null;
|
|
elsif Is_Cons(Car) then
|
|
declare
|
|
Formals: Object_Pointer := Car;
|
|
V: Object_Pointer;
|
|
begin
|
|
Cdr := Formals;
|
|
loop
|
|
Car := Get_Car(Cdr); -- <formal argument>
|
|
if not Is_Symbol(Car) then
|
|
Ada.Text_IO.Put_Line ("WRONG FORMAL FOR LAMBDA");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
-- Check for a duplication formal argument
|
|
-- TODO: make duplication check optional or change the implementation more efficient so that this check is not repeated
|
|
V := Formals;
|
|
loop
|
|
exit when V = Cdr;
|
|
|
|
if Get_Car(V) = Car then
|
|
Ada.Text_IO.Put_Line ("DUPLICATE FORMAL FOR LAMBDA");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
V := Get_Cdr(V);
|
|
end loop;
|
|
|
|
-- Move on to the next formal argument
|
|
Cdr := Get_Cdr(Cdr);
|
|
exit when not Is_Cons(Cdr);
|
|
end loop;
|
|
end;
|
|
|
|
if Cdr /= Nil_Pointer and then not Is_Symbol(Cdr) then
|
|
Ada.Text_IO.Put_Line ("FUCKING CDR IN FORMALS FOR LAMBDA");
|
|
raise Syntax_Error;
|
|
end if;
|
|
else
|
|
Ada.Text_IO.Put_Line ("INVALID FORMALS FOR LAMBDA");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
Cdr := Get_Cdr(Operand); -- cons cell containing <body>
|
|
if not Is_Cons(Cdr) then
|
|
Ada.Text_IO.Put_Line ("NO BODY");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
if Get_Last_Cdr(Cdr) /= Nil_Pointer then
|
|
-- (lambda (x y) (+ x y) . 99)
|
|
Ada.Text_IO.Put_Line ("FUCKING CDR IN BODY FOR LAMBDA");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
declare
|
|
Closure: Object_Pointer;
|
|
begin
|
|
Closure := Make_Closure(Interp.Self, Operand, Interp.Environment);
|
|
Pop_Frame (Interp); -- Done
|
|
Chain_Frame_Result (Interp, Interp.Stack, Closure);
|
|
end;
|
|
end Evaluate_Lambda_Syntax;
|
|
|
|
procedure Evaluate_Let_Syntax is
|
|
pragma Inline (Evaluate_Let_Syntax);
|
|
|
|
Bindings: Object_Pointer;
|
|
LetBody: Object_Pointer;
|
|
begin
|
|
-- let <bindings> <body>
|
|
Operand := Cdr; -- Skip "let".
|
|
if not Is_Cons(Operand) then
|
|
-- e.g) (let)
|
|
-- (let . 10)
|
|
Ada.Text_IO.Put_LINE ("FUCKNING CDR FOR LET");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
Bindings := Get_Car(Operand); -- <bindings>
|
|
if not Is_Cons(Bindings) then
|
|
Ada.Text_IO.Put_Line ("INVALID BINDINGS FOR LET");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
Letbody := Get_Cdr(Operand); -- Cons cell to <body>
|
|
if not Is_Cons(Letbody) then
|
|
-- (let ((x 2)) )
|
|
-- (let ((x 2)) . 99)
|
|
Ada.Text_IO.Put_Line ("INVALID BODY FOR LET");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
Cdr := Bindings;
|
|
loop
|
|
Car := Get_Car(Cdr); -- <binding>
|
|
if not Is_Cons(Car) or else not Is_Cons(Get_Cdr(Car)) or else Get_Cdr(Get_Cdr(Car)) /= Nil_Pointer then
|
|
-- no binding name or no binding value or garbage after that
|
|
Ada.Text_IO.Put_Line ("WRONG BINDING FOR LET");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
if not Is_Symbol(Get_Car(Car)) then
|
|
Ada.Text_IO.Put_Line ("WRONG BINDING NAME FOR LET");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
-- Check for a duplicate binding name
|
|
-- TODO: make duplication check optional or change the implementation more efficient so that this check is not repeated
|
|
declare
|
|
V: Object_Pointer;
|
|
begin
|
|
V := Bindings;
|
|
loop
|
|
exit when V = Cdr;
|
|
|
|
if Get_Car(Get_Car(V)) = Get_Car(Car) then
|
|
Ada.Text_IO.Put_Line ("DUPLICATE BINDING FOR LET");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
V := Get_Cdr(V);
|
|
end loop;
|
|
end;
|
|
|
|
-- Move on to the next binding
|
|
Cdr := Get_Cdr(Cdr);
|
|
exit when not Is_Cons(Cdr);
|
|
end loop;
|
|
|
|
if Cdr /= Nil_Pointer then
|
|
-- The last cdr is not nil.
|
|
Ada.Text_IO.Put_Line ("FUCKING CDR FOR LET BINDING");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
-- To avoid problems of temporary object pointer problems.
|
|
Car := Bindings;
|
|
Cdr := LetBody;
|
|
|
|
Set_Frame_Opcode (Interp.Stack, Opcode_Let_Finish);
|
|
Set_Frame_Operand (Interp.Stack, Cdr);
|
|
|
|
Push_Frame (Interp, Opcode_Let_Binding, Car);
|
|
Push_Frame (Interp, Opcode_Let_Evaluation, Car);
|
|
end Evaluate_Let_Syntax;
|
|
|
|
procedure Evaluate_Letast_Syntax is
|
|
pragma Inline (Evaluate_Letast_Syntax);
|
|
begin
|
|
|
|
--Set_Frame_Opcode (Interp.Stack, Opcode_Let_Finish);
|
|
--Set_Frame_Operand (Interp.Stack, Cdr);
|
|
|
|
--Push_Frame (Interp, Opcode_Let_Binding, Car);
|
|
--Push_Frame (Interp, Opcode_Let_Evaluation, Car);
|
|
null;
|
|
end Evaluate_Letast_Syntax;
|
|
|
|
procedure Evaluate_Quote_Syntax is
|
|
pragma Inline (Evaluate_Quote_Syntax);
|
|
begin
|
|
Operand := Cdr; -- Skip "quote". Get the first argument.
|
|
if not Is_Cons(Operand) then
|
|
-- e.g) (quote)
|
|
-- (quote . 10)
|
|
Ada.Text_IO.Put_LINE ("FUCKNING CDR FOR QUOTE");
|
|
raise Syntax_Error;
|
|
elsif Get_Cdr(Operand) /= Nil_Pointer then
|
|
Ada.Text_IO.Put_LINE ("WRONG NUMBER OF ARGUMENTS FOR QUOTE");
|
|
raise Syntax_Error;
|
|
end if;
|
|
Pop_Frame (Interp); -- Done
|
|
Chain_Frame_Result (Interp, Interp.Stack, Get_Car(Operand));
|
|
end Evaluate_Quote_Syntax;
|
|
|
|
procedure Evaluate_Set_Syntax is
|
|
pragma Inline (Evaluate_Set_Syntax);
|
|
begin
|
|
-- (set! <variable> <expression>)
|
|
-- e.g) (set! x 10)
|
|
|
|
Operand := Cdr; -- Skip "set!"
|
|
|
|
if not Is_Cons(Operand) or else not Is_Cons(Get_Cdr(Operand)) then
|
|
-- e.g) (set!)
|
|
-- (set . 10)
|
|
-- (set x . 10)
|
|
Ada.Text_IO.Put_LINE ("TOO FEW ARGUMENTS FOR SET");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
Car := Get_Car(Operand); -- <variable>
|
|
Cdr := Get_Cdr(Operand); -- cons cell to <expression>
|
|
if Is_Symbol(Car) then
|
|
if Get_Cdr(Cdr) /= Nil_Pointer then
|
|
Ada.Text_IO.Put_LINE ("TOO MANY ARGUMENTS FOR set!");
|
|
raise Syntax_Error;
|
|
end if;
|
|
Cdr := Get_Car(Cdr); -- <expression>
|
|
|
|
-- Arrange to finish setting a variable after <expression> evaluation.
|
|
Set_Frame_Opcode (Interp.Stack, Opcode_Finish_Set_Syntax);
|
|
Set_Frame_Operand (Interp.Stack, Car);
|
|
|
|
-- Arrange to evalaute the value part
|
|
Push_Frame (Interp, Opcode_Evaluate_Object, Cdr);
|
|
else
|
|
Ada.Text_IO.Put_LINE ("INVALID SYMBOL AFTER SET!");
|
|
raise Syntax_Error;
|
|
end if;
|
|
end Evaluate_Set_Syntax;
|
|
|
|
begin
|
|
Push_Top (Interp, Operand'Unchecked_Access);
|
|
Push_Top (Interp, Car'Unchecked_Access);
|
|
Push_Top (Interp, Cdr'Unchecked_Access);
|
|
|
|
<<Start_Over>>
|
|
Operand := Get_Frame_Operand(Interp.Stack);
|
|
|
|
if not Is_Normal_Pointer(Operand) then
|
|
-- integer, character, specal pointers
|
|
-- TODO: some normal pointers may point to literal objects. e.g.) bignum
|
|
goto Literal;
|
|
end if;
|
|
|
|
case Operand.Tag is
|
|
when Symbol_Object => -- Is_Symbol(Operand)
|
|
-- TODO: find it in the Environment hierarchy.. not in the current environemnt.
|
|
Car := Get_Environment (Interp.Self, Operand);
|
|
if Car = null then
|
|
-- unbound
|
|
Ada.Text_IO.Put_Line ("Unbound symbol....");
|
|
Print (Interp, Operand);
|
|
raise Evaluation_Error;
|
|
else
|
|
-- symbol found in the environment
|
|
Operand := Car;
|
|
goto Literal; -- In fact, this is not a literal, but can be handled in the same way
|
|
end if;
|
|
|
|
when Cons_Object => -- Is_Cons(Operand)
|
|
Car := Get_Car(Operand);
|
|
Cdr := Get_Cdr(Operand);
|
|
if Is_Syntax(Car) then
|
|
-- special syntax symbol. normal evaluate rule doesn't
|
|
-- apply for special syntax objects.
|
|
|
|
case Car.Scode is
|
|
when And_Syntax =>
|
|
Evaluate_And_Syntax;
|
|
|
|
when Begin_Syntax =>
|
|
|
|
Operand := Cdr; -- Skip "begin"
|
|
|
|
if not Is_Cons(Operand) then
|
|
-- e.g) (begin)
|
|
-- (begin . 10)
|
|
Ada.Text_IO.Put_LINE ("FUCKNING CDR FOR BEGIN");
|
|
raise Syntax_Error;
|
|
|
|
else
|
|
Set_Frame_Opcode (Interp.Stack, Opcode_Evaluate_Group);
|
|
Set_Frame_Operand (Interp.Stack, Operand);
|
|
|
|
if (Interp.Trait.Trait_Bits and No_Optimization) = 0 then
|
|
-- I call Evaluate_Group for optimization here.
|
|
Evaluate_Group; -- for optimization only. not really needed.
|
|
-- I can jump to Start_Over because Evaluate_Group called
|
|
-- above pushes an Opcode_Evaluate_Object frame.
|
|
pragma Assert (Get_Frame_Opcode(Interp.Stack) = Opcode_Evaluate_Object);
|
|
goto Start_Over; -- for optimization only. not really needed.
|
|
end if;
|
|
end if;
|
|
|
|
when Define_Syntax =>
|
|
Evaluate_Define_Syntax;
|
|
|
|
when If_Syntax =>
|
|
Evaluate_If_Syntax;
|
|
|
|
when Lambda_Syntax =>
|
|
Evaluate_Lambda_Syntax;
|
|
|
|
when Let_Syntax =>
|
|
Evaluate_Let_Syntax;
|
|
|
|
when Letast_Syntax =>
|
|
Evaluate_Letast_Syntax;
|
|
|
|
when Or_Syntax =>
|
|
Evaluate_Or_Syntax;
|
|
|
|
when Quote_Syntax =>
|
|
Evaluate_Quote_Syntax;
|
|
|
|
when Set_Syntax => -- set!
|
|
Evaluate_Set_Syntax;
|
|
|
|
when others =>
|
|
Ada.Text_IO.Put_Line ("Unknown syntax");
|
|
--Set_Frame_Opcode (Interp.Stack, Opcode_Evaluate_Syntax); -- Switch to syntax evaluation
|
|
raise Internal_Error;
|
|
end case;
|
|
else
|
|
if (Interp.Trait.Trait_Bits and No_Optimization) = 0 then
|
|
while not Is_Normal_Pointer(Car) loop
|
|
-- This while block is for optimization only. It's not really needed.
|
|
-- If I know that the next object to evaluate is a literal object,
|
|
-- I can simply reverse-chain it to the return field of the current
|
|
-- frame without pushing another frame dedicated for it.
|
|
|
|
-- TODO: some normal pointers may point to a literal object. e.g.) bignum
|
|
-- then it can goto <<Literal>>.
|
|
Chain_Frame_Result (Interp, Interp.Stack, Car);
|
|
if Is_Cons(Cdr) then
|
|
Operand := Cdr;
|
|
Car := Get_Car(Operand);
|
|
Cdr := Get_Cdr(Operand);
|
|
else
|
|
-- last cons
|
|
if Cdr /= Nil_Pointer then
|
|
-- The last CDR is not Nil.
|
|
Ada.Text_IO.Put_Line ("WARNING: $$$$$$$$$$$$$$$$$$$$$..FUCKING CDR.....................OPTIMIZATIN $$$$");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
Operand := Reverse_Cons(Get_Frame_Result(Interp.Stack));
|
|
Clear_Frame_Result (Interp.Stack);
|
|
Set_Frame_Opcode (Interp.Stack, Opcode_Apply);
|
|
Set_Frame_Operand (Interp.Stack, Operand);
|
|
goto Done;
|
|
end if;
|
|
end loop;
|
|
end if;
|
|
|
|
if Is_Cons(Cdr) then
|
|
-- Not the last cons cell yet
|
|
Set_Frame_Operand (Interp.Stack, Cdr); -- change the operand for the next call
|
|
else
|
|
-- Reached the last cons cell
|
|
if Cdr /= Nil_Pointer then
|
|
-- The last CDR is not Nil.
|
|
Ada.Text_IO.Put_Line ("WARNING: $$$$$$$$$$$$$$$$$$$$$..FUCKING CDR.....................$$$$");
|
|
raise Syntax_Error;
|
|
end if;
|
|
|
|
-- Change the operand to a mark object so that the call to this
|
|
-- procedure after the evaluation of the last car goes to the
|
|
-- Mark_Object case.
|
|
Set_Frame_Operand (Interp.Stack, Interp.Mark);
|
|
end if;
|
|
|
|
-- Arrange to evaluate the car object
|
|
if (Interp.Trait.Trait_Bits and No_Optimization) = 0 then
|
|
Push_Frame (Interp, Opcode_Evaluate_Object, Car);
|
|
goto Start_Over; -- for optimization only. not really needed.
|
|
end if;
|
|
end if;
|
|
|
|
when Mark_Object =>
|
|
-- TODO: you can use the mark context to differentiate context
|
|
|
|
-- Get the evaluation result stored in the current stack frame by
|
|
-- various sub-Opcode_Evaluate_Object frames. the return value
|
|
-- chain must be reversed Chain_Frame_Result reverse-chains values.
|
|
Operand := Reverse_Cons(Get_Frame_Result(Interp.Stack));
|
|
|
|
-- Refresh the current stack frame to Opcode_Apply.
|
|
-- This should be faster than Popping the current frame and pushing
|
|
-- a new frame.
|
|
-- Envir := Get_Frame_Environment(Interp.Stack);
|
|
-- Pop_Frame (Interp); -- done
|
|
-- Push_Frame (Interp, Opcode_Apply, Operand, Envir);
|
|
Clear_Frame_Result (Interp.Stack);
|
|
Set_Frame_Opcode (Interp.Stack, Opcode_Apply);
|
|
Set_Frame_Operand (Interp.Stack, Operand);
|
|
|
|
when others =>
|
|
-- normal literal object
|
|
goto Literal;
|
|
end case;
|
|
goto Done;
|
|
|
|
<<Literal>>
|
|
Pop_Frame (Interp); -- done
|
|
Ada.Text_IO.Put ("Return => ");
|
|
Print (Interp, Operand);
|
|
Chain_Frame_Result (Interp, Interp.Stack, Operand);
|
|
goto Done;
|
|
|
|
<<Done>>
|
|
Pop_Tops (Interp, 3);
|
|
end Evaluate;
|