* Loading:: Loading Scheme code from file.
* Character Encoding of Source Files:: Loading non-ASCII Scheme code from file.
* Delayed Evaluation:: Postponing evaluation until it is needed.
-* Evaluator Behaviour:: Modifying Guile's evaluator.
* VM Behaviour:: Modifying Guile's virtual machine.
@end menu
@end deffn
-@node Evaluator Behaviour
-@subsection Evaluator Behaviour
-
-@c FIXME::martin: Maybe this node name is bad, but the old name clashed with
-@c `Evaluator options' under `Options and Config'.
-
-The behaviour of Guile's evaluator can be modified by manipulating the
-evaluator options. For more information about options, @xref{User level
-options interfaces}.
-
-@c FIXME::martin: Why aren't these procedure named like the other options
-@c procedures?
-
-@deffn {Scheme Procedure} traps [setting]
-Display the current settings of the evaluator traps options. If
-@var{setting} is omitted, only a short form of the current evaluator
-traps options is printed. Otherwise, @var{setting} should be one of the
-following symbols:
-@table @code
-@item help
-Display the complete option settings.
-@item full
-Like @code{help}, but also print programmer options.
-@end table
-@end deffn
-
-@deffn {Scheme Procedure} trap-enable option-name
-@deffnx {Scheme Procedure} trap-disable option-name
-@deffnx {Scheme Procedure} trap-set! option-name value
-Modify the evaluator options. @code{trap-enable} should be used with boolean
-options and switches them on, @code{trap-disable} switches them off.
-@code{trap-set!} can be used to set an option to a specific value.
-
-See @ref{Evaluator trap options} for more information on the available
-trap handlers.
-@end deffn
-
-@deffn {Scheme Procedure} evaluator-traps-interface [setting]
-@deffnx {C Function} scm_evaluator_traps (setting)
-Option interface for the evaluator trap options.
-@end deffn
-
@node VM Behaviour
@subsection VM Behaviour
* Reader options::
* Printing options::
* Debugger options::
-* Evaluator trap options::
* Examples of option use::
@end menu
@deffn {Scheme Procedure} read-options-interface [setting]
@deffnx {Scheme Procedure} print-options-interface [setting]
@deffnx {Scheme Procedure} debug-options-interface [setting]
-@deffnx {Scheme Procedure} evaluator-traps-interface [setting]
@deffnx {C Function} scm_read_options (setting)
-@deffnx {C Function} scm_eval_options_interface (setting)
@deffnx {C Function} scm_print_options (setting)
@deffnx {C Function} scm_debug_options (setting)
-@deffnx {C Function} scm_evaluator_traps (setting)
If one of these procedures is called with no arguments (or with
@code{setting == SCM_UNDEFINED} in C code), it returns a list describing
the current setting of the read, eval, print, debug or evaluator traps
@deffnx {Scheme Procedure} read-options [arg]
@deffnx {Scheme Procedure} print-options [arg]
@deffnx {Scheme Procedure} debug-options [arg]
-@deffnx {Scheme Procedure} traps [arg]
These functions list the options in their group. The optional argument
@var{arg} is a symbol which modifies the form in which the options are
presented.
@deffnx {Scheme Procedure} read-enable option-symbol
@deffnx {Scheme Procedure} print-enable option-symbol
@deffnx {Scheme Procedure} debug-enable option-symbol
-@deffnx {Scheme Procedure} trap-enable option-symbol
These functions set the specified @var{option-symbol} in their options
group. They only work if the option is boolean, and throw an error
otherwise.
@deffnx {Scheme Procedure} read-disable option-symbol
@deffnx {Scheme Procedure} print-disable option-symbol
@deffnx {Scheme Procedure} debug-disable option-symbol
-@deffnx {Scheme Procedure} trap-disable option-symbol
These functions turn off the specified @var{option-symbol} in their
options group. They only work if the option is boolean, and throw an
error otherwise.
@deffnx syntax read-set! option-symbol value
@deffnx syntax print-set! option-symbol value
@deffnx syntax debug-set! option-symbol value
-@deffnx syntax trap-set! option-symbol value
These functions set a non-boolean @var{option-symbol} to the specified
@var{value}.
@end deffn
@end smallexample
-@node Evaluator trap options
-@subsubsection Evaluator trap options
-[FIXME: These flags, together with their corresponding handlers, are not
-user level options. Probably this entire section should be moved to the
-documentation about the low-level programmer debugging interface.]
-
-Here is the list of evaluator trap options generated by typing
-@code{(traps 'full)} in Guile. You can also see the default values.
-
-@smallexample
-exit-frame no Trap when exiting eval or apply.
-apply-frame no Trap when entering apply.
-enter-frame no Trap when eval enters new frame.
-memoize-symbol no Trap when eval memoizes a symbol's value
-traps yes Enable evaluator traps.
-@end smallexample
-
-@deffn apply-frame-handler key cont tailp
-Called when a procedure is being applied.
-
-Called if:
-
-@itemize @bullet
-@item
-evaluator traps are enabled [traps interface], and
-@item
-either
-@itemize @minus
-@item
-@code{apply-frame} is enabled [traps interface], or
-@item
-trace mode is on [debug-options interface], and the procedure being
-called has the trace property enabled.
-@end itemize
-@end itemize
-
-@var{cont} is a ``debug object'', which means that it can be passed to
-@code{make-stack} to discover the stack at the point of the trap. The
-apply frame handler's code can capture a restartable continuation if it
-wants to by using @code{call-with-current-continuation} in the usual way.
-
-@var{tailp} is true if this is a tail call
-@end deffn
-
-@deffn exit-frame-handler key cont retval
-Called when a value is returned from a procedure.
-
-Called if:
-
-@itemize @bullet
-@item
-evaluator traps are enabled [traps interface], and
-@item
-either
-@itemize @minus
-@item
- @code{exit-frame} is enabled [traps interface], or
-@item
-trace mode is on [debug-options interface], and the procedure being
-called has the trace property enabled.
-@end itemize
-@end itemize
-
-@var{cont} is a ``debug object'', which means that it can be passed to
-@code{make-stack} to discover the stack at the point of the trap. The
-exit frame handler's code can capture a restartable continuation if it
-wants to by using @code{call-with-current-continuation} in the usual
-way.
-
-@var{retval} is the return value.
-@end deffn
-
-@deffn memoize-symbol-handler key cont expression env
-Called when the evaluator memoizes the value of a procedure symbol
-
-@var{cont} is a ``debug object'', which means that it can be passed to
-@code{make-stack} to discover the stack at the point of the trap. The
-exit frame handler's code can capture a restartable continuation if it
-wants to by using @code{call-with-current-continuation} in the usual
-way.
-
-@var{retval} is the return value.
-@end deffn
-
-@deffn {Scheme Procedure} with-traps thunk
-@deffnx {C Function} scm_with_traps (thunk)
-Call @var{thunk} with traps enabled.
-@end deffn
-
-@deffn {Scheme Procedure} debug-object? obj
-@deffnx {C Function} scm_debug_object_p (obj)
-Return @code{#t} if @var{obj} is a debug object.
-@end deffn
-
-
@node Debugger options
@subsubsection Debugger options
}
#undef FUNC_NAME
-
-static void
-with_traps_before (void *data)
-{
- int *trap_flag = data;
- *trap_flag = SCM_TRAPS_P;
- SCM_TRAPS_P = 1;
-}
-
-static void
-with_traps_after (void *data)
-{
- int *trap_flag = data;
- SCM_TRAPS_P = *trap_flag;
-}
-
-static SCM
-with_traps_inner (void *data)
-{
- SCM thunk = SCM_PACK ((scm_t_bits) data);
- return scm_call_0 (thunk);
-}
-
-SCM_DEFINE (scm_with_traps, "with-traps", 1, 0, 0,
- (SCM thunk),
- "Call @var{thunk} with traps enabled.")
-#define FUNC_NAME s_scm_with_traps
-{
- int trap_flag;
- SCM_VALIDATE_THUNK (1, thunk);
- return scm_internal_dynamic_wind (with_traps_before,
- with_traps_inner,
- with_traps_after,
- (void *) SCM_UNPACK (thunk),
- &trap_flag);
-}
-#undef FUNC_NAME
-
\f
SCM_SYMBOL (scm_sym_source, "source");
SCM_API SCM scm_reverse_lookup (SCM env, SCM data);
SCM_API SCM scm_procedure_source (SCM proc);
SCM_API SCM scm_procedure_name (SCM proc);
-SCM_API SCM scm_with_traps (SCM thunk);
-SCM_API SCM scm_evaluator_traps (SCM setting);
SCM_API SCM scm_debug_options (SCM setting);
SCM_INTERNAL void scm_init_debug (void);
};
-/*
- * this ordering is awkward and illogical, but we maintain it for
- * compatibility. --hwn
- */
-scm_t_option scm_evaluator_trap_table[] = {
- { SCM_OPTION_BOOLEAN, "traps", 0, "Enable evaluator traps." },
- { SCM_OPTION_BOOLEAN, "enter-frame", 0, "Trap when eval enters new frame." },
- { SCM_OPTION_BOOLEAN, "apply-frame", 0, "Trap when entering apply." },
- { SCM_OPTION_BOOLEAN, "exit-frame", 0, "Trap when exiting eval or apply." },
- { SCM_OPTION_SCM, "enter-frame-handler", (unsigned long)SCM_BOOL_F, "Handler for enter-frame traps." },
- { SCM_OPTION_SCM, "apply-frame-handler", (unsigned long)SCM_BOOL_F, "Handler for apply-frame traps." },
- { SCM_OPTION_SCM, "exit-frame-handler", (unsigned long)SCM_BOOL_F, "Handler for exit-frame traps." },
- { SCM_OPTION_BOOLEAN, "memoize-symbol", 0, "Trap when memoizing a symbol." },
- { SCM_OPTION_SCM, "memoize-symbol-handler", (unsigned long)SCM_BOOL_F, "The handler for memoization." },
- { 0 }
-};
-
-
-SCM_DEFINE (scm_evaluator_traps, "evaluator-traps-interface", 0, 1, 0,
- (SCM setting),
- "Option interface for the evaluator trap options.")
-#define FUNC_NAME s_scm_evaluator_traps
-{
- SCM ans;
-
-
- scm_options_try (setting,
- scm_evaluator_trap_table,
- FUNC_NAME, 1);
- SCM_CRITICAL_SECTION_START;
- ans = scm_options (setting,
- scm_evaluator_trap_table,
- FUNC_NAME);
-
- /* njrev: same again. */
- SCM_CRITICAL_SECTION_END;
- return ans;
-}
-#undef FUNC_NAME
-
-
-
\f
/* Simple procedure calls
{
SCM primitive_eval;
- scm_init_opts (scm_evaluator_traps,
- scm_evaluator_trap_table);
-
f_apply = scm_c_define_gsubr ("apply", 2, 0, 1, scm_apply);
scm_tc16_boot_closure = scm_make_smob_type ("boot-closure", 0);
#ifndef PRIVATE_OPTIONS
#define PRIVATE_OPTIONS
-/*
- evaluator
- */
-SCM_API scm_t_option scm_evaluator_trap_table[];
-
-#define SCM_TRAPS_P scm_evaluator_trap_table[0].val
-#define SCM_ENTER_FRAME_P scm_evaluator_trap_table[1].val
-#define SCM_APPLY_FRAME_P scm_evaluator_trap_table[2].val
-#define SCM_EXIT_FRAME_P scm_evaluator_trap_table[3].val
-#define SCM_ENTER_FRAME_HDLR (SCM_PACK (scm_evaluator_trap_table[4].val))
-#define SCM_APPLY_FRAME_HDLR (SCM_PACK (scm_evaluator_trap_table[5].val))
-#define SCM_EXIT_FRAME_HDLR (SCM_PACK (scm_evaluator_trap_table[6].val))
-#define SCM_MEMOIZE_P scm_evaluator_trap_table[7].val
-#define SCM_MEMOIZE_HDLR (SCM_PACK (scm_evaluator_trap_table[8].val))
-
/*
debugging.
*/
(debug-options debug-enable debug-disable)
(debug-set!)))
-(define-option-interface
- (evaluator-traps-interface
- (traps trap-enable trap-disable)
- (trap-set!)))
-
(define-option-interface
(read-options-interface
(read-options read-enable read-disable)
(lambda ()
(call-with-unblocked-asyncs
(lambda ()
- (with-traps
- (lambda ()
- (first)
-
- ;; This line is needed because mark
- ;; doesn't do closures quite right.
- ;; Unreferenced locals should be
- ;; collected.
- (set! first #f)
- (let loop ((v (thunk)))
- (loop (thunk)))
- #f)))))
+ (first)
+
+ ;; This line is needed because mark
+ ;; doesn't do closures quite right.
+ ;; Unreferenced locals should be
+ ;; collected.
+ (set! first #f)
+ (let loop ((v (thunk)))
+ (loop (thunk)))
+ #f)))
(lambda (key . args)
(case key
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