4 files changed, 54 insertions(+), 16 deletions(-)

M prolog/eshellisp/eval.pl
M prolog/eshellisp/read.pl
M prolog/eshellisp/write.pl
A scheme/stacktrace.scm

@@ 30,9 30,9 @@ evaluate_forms([], _, _, _, Value, Value, []).
 
 
 evaluate_form(Form, Value) :-
-    evaluate_form(Form, dynamic, dynamic, [], '#f', Value).
+    evaluate_form(Form, dyn, dyn, [], '#f', Value).
 
-evaluate_form(_, _, _, _, exception(What, Where), exception(What, Where)) :- !.
+evaluate_form(_, File, Layout, _, exception(What, Where), exception(What, [File:Layout|Where])) :- !.
 evaluate_form([import, SpecList], File, Layout, Vars, Value0, Value) :-
     !,
     Spec =.. SpecList,


@@ 42,7 42,7 @@ evaluate_form([import, SpecList], File, Layout, Vars, Value0, Value) :-
     ->  read_program(file(Path), Program, [positions(Positions)]),
         evaluate_program(Program, Path, Positions, Vars, Value0, Value)
     ;   sub_layout(2, Layout, SpecLayout),
-        Value = exception(import_error(Spec), File:SpecLayout)
+        Value = exception(import_error(Spec), [File:SpecLayout])
     ).
 evaluate_form([define, Name, Args | Body], File, Layout, _, _, quote(Name)) :-
     !,


@@ 65,7 65,9 @@ evaluate_form([Name | Args], File, Layout, Vars, Value0, Value) :-
     sub_layout(1, Layout, PName),
     sub_layouts(1, Layout, PArgs),
     evaluate_forms(Args, File, PArgs, Vars, Value0, Value1, Vals),
-    (   defined(Name, A, Body, F, P)
+    (   Value1 = exception(What, Where)
+    ->  Value  = exception(What, [File:Layout|Where])
+    ;   defined(Name, A, Body, F, P)
     ->  (   maplist([Arg,Val,Arg=Val]>>true, A, Vals, Vars1)
         ->  append(Vars1, Vars, Vars2),
             evaluate_program(Body, F, P, Vars2, Value1, Value)


@@ 73,14 75,18 @@ evaluate_form([Name | Args], File, Layout, Vars, Value0, Value) :-
         )
     ;   primitive(Name, Vals, Value2)
     ->  (   Value2 = exception(What)
-        ->  Value  = exception(What, File:PName)
+        ->  Value  = exception(What, [File:PName])
         ;   Value  = Value2
         )
-    ;   Value = exception(no_such_function(Name), File:PName)
+    ;   Value = exception(no_such_function(Name), [File:PName])
     ).
 evaluate_form(quote(E), _, _, _, _, E) :- !.
 evaluate_form('#t', _, _, _, _, '#t') :- !.
 evaluate_form('#f', _, _, _, _, '#f') :- !.
+evaluate_form('#end-of-file', _, _, _, _, _) :-
+    !,
+    write_form('#end-of-file'),
+    halt(0).
 evaluate_form(Number, _, _, _, _, Number) :-
     number(Number),
     !.


@@ 89,7 95,7 @@ evaluate_form(Symbol, File, Layout, Vars, _, Value) :-
     !,
     (   memberchk(Symbol=Value, Vars)
     ->  true
-    ;   Value = exception(no_such_symbol(Symbol), File:Layout)
+    ;   Value = exception(no_such_symbol(Symbol), [File:Layout])
     ).
 
 


@@ 114,18 120,18 @@ primitive('cdr',    [O] , exception(no_cons(O))) :- !.
 
 
 
-sub_layout(_, dynamic, dynamic) :- !.
+sub_layout(_, dyn, dyn) :- !.
 sub_layout(N, layout(_, _, Subs), Sub) :-
     !,
     nth1(N, Subs, Sub).
 
 
-sub_layouts(_, dynamic, dynamic) :- !.
+sub_layouts(_, dyn, dyn) :- !.
 sub_layouts(Skip, layout(_, _, Subs0), Subs) :-
     !,
     length(Prefix, Skip),
     append(Prefix, Subs, Subs0).
 
 
-layouts_parts(dynamic, dynamic, dynamic) :- !.
+layouts_parts(dyn, dyn, dyn) :- !.
 layouts_parts([H|T], H, T).

@@ 27,9 27,12 @@ read_program(Stream, Program, Options) :-
 read_form(Expression) :-
     prompt1('% '),
     read_line_to_codes(current_input, Codes),
-    phrase(tokens(Tokens), Codes),
-    phrase(forms([Form], position(1, 0, 0), _), Tokens),
-    form_components(Form, Expression, _).
+    (   Codes == end_of_file
+    ->  Expression = '#end-of-file'
+    ;   phrase(tokens(Tokens), Codes),
+        phrase(forms([Form], position(1, 0, 0), _), Tokens),
+        form_components(Form, Expression, _)
+    ).
 
 parse(Tokens, Expressions, Options) :-
     phrase(forms(Forms, position(1, 0, 0), _), Tokens),

@@ 2,19 2,22 @@
           [ write_form/1   % +Value
           ]).
 
+
 write_form(Value) :-
     print_message(information, eshellisp(Value)).
 
+
 :- multifile prolog:message//1.
 
 prolog:message(eshellisp(Value)) -->
     !,
     form(Value).
 
-form(exception(What, Path:layout(position(Line, Column, _), _, _))) -->
+
+form(exception(What, [H|T])) -->
     !,
-    { absolute_file_name(Path, Abs) },
-    [ 'Exception ~w at ~w:~w:~w'-[What, Abs, Line, Column] ].
+    exception(What, H),
+    stack(T).
 form(quote(Value)) -->
     !,
     [ '\''-[] ],


@@ 48,3 51,22 @@ cdr(Form) -->
     [ ' . '-[] ],
     form(Form),
     [ ')'-[] ].
+
+
+exception(What, dyn:dyn) -->
+    !,
+    [ 'Exception ~w'-[What] ].
+exception(What, Path:layout(position(Line, Column, _), _, _)) -->
+    !,
+    { absolute_file_name(Path, Abs) },
+    [ 'Exception ~w at '-[What], url(Abs:Line:Column) ].
+
+stack([dyn:dyn|T]) -->
+    !,
+    stack(T).
+stack([Path:layout(position(Line, Column, _), _, _)|T]) -->
+    !,
+    { absolute_file_name(Path, Abs) },
+    [ nl, '    Called from '-[], url(Abs:Line:Column) ],
+    stack(T).
+stack([]) --> !.

@@ 0,0 1,7 @@
+(define foo (a) (cdr a))
+(define bar (a) (car a))
+
+(write (+ 1 (bar
+             (foo
+              (foo
+               '(2 3))))))