* libguile/exceptions.c (exception_epoch_fluid): Rename from
active_exception_handlers_fluid.
(scm_dynwind_throw_handler): Increment exception epoch instead of
resetting active exception handlers.
(scm_init_exceptions): Update.
* module/ice-9/boot-9.scm (with-exception-handler): Rework to associate
an "epoch" fluid with each exception handler.
(with-throw-handler): Establish a new epoch, during the execution of a
throw handler.
(raise-exception): Rework to avoid capturing a list of exception
handlers, and to use epochs as a way to know which handlers have already
been examined and which are on the dispatch stack.
* test-suite/tests/exceptions.test ("throwing within exception
handlers"): New test.
* libguile/exceptions.c:
* libguile/exceptions.h: New files.
* libguile.h: Add exceptions.h.
* libguile/Makefile.am (libguile_@GUILE_EFFECTIVE_VERSION@_la_SOURCES):
(DOT_X_FILES, DOT_DOC_FILES, modinclude_HEADERS): Add exceptions.c and
exceptions.h.
* libguile/init.c (scm_i_init_guile): Initialize exceptions.
* libguile/threads.c (scm_spawn_thread): Use new names for
scm_i_make_catch_handler and scm_c_make_thunk.
* libguile/throw.c: Rewrite to be implemented in terms of
with-exception-handler / raise-exception.
* libguile/throw.h: Use data types from exceptions.h. Move
scm_report_stack_overflow and scm_report_out_of_memory to
exceptions.[ch].
* module/ice-9/boot-9.scm (&error, &programming-error)
(&non-continuable, make-exception-from-throw, raise-exception)
(with-exception-handler): New top-level definitions.
(throw, catch, with-throw-handler): Rewrite in terms of
with-exception-handler and raise-exception.
: New top-level definitions.
* module/ice-9/exceptions.scm: Adapt to re-export &error,
&programming-error, &non-continuable, raise-exception, and
with-exception-handler from boot-9.
(make-quit-exception, guile-quit-exception-converter): New exception
converters.
(make-exception-from-throw): Override core binding.
* test-suite/tests/eval.test ("inner trim with prompt tag"): Adapt to
"with-exception-handler" being the procedure on the stack.
("outer trim with prompt tag"): Likewise.
* test-suite/tests/exceptions.test (throw-test): Use pass-if-equal.
* module/srfi/srfi-34.scm: Reimplement in terms of core exceptions, and
make "guard" actually re-raise continuations with the original "raise"
continuation.
* libguile/dynstack.h:
* libguile/dynstack.c (scm_dynstack_find_old_fluid_value): New
function.
* libguile/fluids.c (saved_dynamic_state_ref): New helper.
(scm_fluid_ref): Fix docstring.
(scm_fluid_ref_star): New function allowing access to previous values
for a fluid.
(scm_dynamic_state_ref): New internal function.
* libguile/fluids.h: Add scm_fluid_ref_star and scm_dynamic_state_ref.
* libguile/stacks.c (scm_stack_id): Adapt to %stacks not being a chain.
* libguile/throw.c (catch, throw_without_pre_unwind): Adapt to
%exception-handlers not being a chain.
* module/ice-9/boot-9.scm (catch, dispatch-exception): Instead of having
%exception-handlers be a chain, use fluid-ref* to access the chain
that is in place at the time the exception is thrown. Prevents
unintended undelimited capture of the current exception handler stack
by a delimited "catch".
(%start-stack): Similarly, don't be a chain.
* module/system/repl/debug.scm (frame->stack-vector):
* module/system/repl/error-handling.scm (call-with-error-handling):
* module/ice-9/save-stack.scm (save-stack): Adapt to %stacks not being a
chain.
* test-suite/tests/exceptions.test ("delimited exception handlers"): Add
tests.
* doc/ref/api-control.texi (Fluids and Dynamic States): Add docs.
* test-suite/tests/exceptions.test (push): New syntax parameter.
(throw-test): Convert to a syntax-rules macro, using syntax parameters
to support the otherwise-unhygienic use of "push".
* libguile/deprecated.h:
* libguile/deprecated.c (scm_internal_lazy_catch, scm_lazy_catch):
Deprecate, and print out a nasty warning that people should change to
with-throw-handler.
* libguile/throw.h:
* libguile/throw.c (scm_c_with_throw_handler): Deprecate the use of the
lazy_catch_p argument, printing out a nasty warning if someone
actually passes 1 as that argument. The combination of the pre-unwind
and post-unwind handlers should be sufficient.
* test-suite/tests/exceptions.test: Remove lazy-catch tests, as they are
deprecated. Two of them fail:
* throw/catch: effect of lazy-catch unwinding on throw to another key
* throw/catch: repeat of previous test but with lazy-catch
Hopefully people are not depending on this behavior, and the warning is
sufficiently nasty for people to switch. We will see.
* test-suite/tests/eval.test ("promises"): Use with-throw-handler
instead of lazy-catch.
* doc/ref/api-debug.texi:
* doc/ref/api-control.texi: Update to remove references to lazy-catch,
folding in the useful bits to with-throw-handler.
(syntax lambda cond-arrow-proc): Renamed from (lambda cond-arrow-proc).
(syntax reading): New section.
(syntax let*): New section.
(syntax letrec): New section.
(syntax set!): New section.
(syntax misc): New section.
(bindings unbound): New section.
(bindings immutable-modification): New section.
(bindings let): New section.
(bindings let*): New section.
(bindings letrec): New section.
