def do_rewind_frames(frames, index, env, final_cont):
from pycket.interpreter import return_void
if index < 0:
return return_void(env, final_cont)
frame = frames[index]
ctxt = rewind_next_frame_cont(frames, index, final_cont, env, frame.prev)
return frame.rewind(env, ctxt)
def do_rewind_frames(frames, index, env, final_cont):
from pycket.interpreter import return_void
if index < 0:
return return_void(env, final_cont)
frame = frames[index]
ctxt = rewind_next_frame_cont(frames, index, final_cont, env, frame.prev)
return frame.rewind(env, ctxt)
def default_error_display_handler(msg, exn_object, env, cont):
from pycket.prims.input_output import current_error_param, return_void
port = current_error_param.get(cont)
assert isinstance(port, values.W_OutputPort)
port.write("%s : %s\n" %
(exn_object.struct_type().name.tostring(), msg.tostring()))
# FIXME : FIX the continuation-mark-set->context and extract a stack trace using it
return return_void(env, cont)
def install_continuation_fast_path(current_cont, args, has_handlers, env, cont):
from pycket.interpreter import return_multi_vals, return_void
if not has_handlers:
args = values.Values.make(args)
return return_multi_vals(args, env, cont)
unwind = find_handlers(current_cont, cont)
cont = return_args_cont(args, env, cont)
unwind = [x for x in reversed(unwind)]
cont = do_unwind_cont(unwind, env, cont)
return return_void(env, cont)
def install_continuation_fast_path(current_cont, args, has_handlers, env, cont):
from pycket.interpreter import return_multi_vals, return_void
if not has_handlers:
args = values.Values.make(args)
return return_multi_vals(args, env, cont)
unwind = find_handlers(current_cont, cont)
cont = return_args_cont(args, env, cont)
unwind = [x for x in reversed(unwind)]
cont = do_unwind_cont(unwind, env, cont)
return return_void(env, cont)
def default_error_display_handler(msg, exn_object, env, cont):
from pycket.prims.input_output import current_error_param, return_void
port = current_error_param.get(cont)
assert isinstance(port, values.W_OutputPort)
if is_exn(exn_object):
port.write("%s : %s\n" % (exn_object.struct_type().name.tostring(), msg.tostring()))
else:
port.write("exception : %s\n" % (msg.tostring()))
if not is_user_exn(exn_object):
display_stack_trace(port, cont)
return return_void(env, cont)
def default_error_display_handler(msg, exn_object, env, cont):
from pycket.prims.input_output import current_error_param, return_void
port = current_error_param.get(cont)
assert isinstance(port, values.W_OutputPort)
if is_exn(exn_object):
port.write("%s : %s\n" % (exn_object.struct_type().name.tostring(), msg.tostring()))
else:
port.write("exception : %s\n" % (msg.tostring()))
if not is_user_exn(exn_object):
display_stack_trace(port, cont)
return return_void(env, cont)
def install_continuation(cont,
prompt_tag,
args,
env,
current_cont,
extend=False,
escape=False):
from pycket.interpreter import return_multi_vals, return_void
# Find the common merge point for two continuations
# The extend option controls whether or not we remove frames from the
# existing continuation, or simply stack the new continuation on top.
# This is what differentiates call-with-current-continuation from
# call-with-composable-continuation.
if extend:
_, rewind = find_continuation_prompt(prompt_tag,
cont,
direction='rewind')
base, unwind = current_cont, None
stop = None
else:
head1, handlers = scan_continuation(current_cont,
prompt_tag,
look_for=cont,
escape=escape)
if head1 is None:
return install_continuation_fast_path(current_cont, args, handlers,
env, cont)
head2, _ = scan_continuation(cont, prompt_tag)
base, stop, unwind, rewind = find_merge_point(head1, head2)
# Append the continuations at the appropriate prompt
if base is not None:
cont = cont.append(base, stop=stop, upto=prompt_tag)
# Fast path if no unwinding is required (avoids continuation allocation)
if not unwind and not rewind:
args = values.Values.make(args)
return return_multi_vals(args, env, cont)
# NOTE: All the continuations pushed here expect no arguments
# They simply wrap functions which we could call directly, but using
# continuations to perform the desired sequencing is easier.
cont = return_args_cont(args, env, cont)
if rewind:
cont = do_rewind_cont(rewind, env, cont)
if unwind:
unwind = [x for x in reversed(unwind)]
cont = do_unwind_cont(unwind, env, cont)
return return_void(env, cont)
def install_continuation(cont, prompt_tag, args, env, current_cont, extend=False, escape=False):
from pycket.interpreter import return_multi_vals, return_void
# Find the common merge point for two continuations
# The extend option controls whether or not we remove frames from the
# existing continuation, or simply stack the new continuation on top.
# This is what differentiates call-with-current-continuation from
# call-with-composable-continuation.
if extend:
_ , rewind = find_continuation_prompt(prompt_tag, cont, direction='rewind')
base, unwind = current_cont, None
stop = None
else:
head1, handlers = scan_continuation(
current_cont, prompt_tag, look_for=cont, escape=escape)
if head1 is None:
return install_continuation_fast_path(current_cont, args, handlers, env, cont)
head2, _ = scan_continuation(cont, prompt_tag)
base, stop, unwind, rewind = find_merge_point(head1, head2)
# Append the continuations at the appropriate prompt
if base is not None:
cont = cont.append(base, stop=stop, upto=prompt_tag)
# Fast path if no unwinding is required (avoids continuation allocation)
if not unwind and not rewind:
args = values.Values.make(args)
return return_multi_vals(args, env, cont)
# NOTE: All the continuations pushed here expect no arguments
# They simply wrap functions which we could call directly, but using
# continuations to perform the desired sequencing is easier.
cont = return_args_cont(args, env, cont)
if rewind:
cont = do_rewind_cont(rewind, env, cont)
if unwind:
unwind = [x for x in reversed(unwind)]
cont = do_unwind_cont(unwind, env, cont)
return return_void(env, cont)
def rewind(self, env, cont):
from pycket.interpreter import return_void
return return_void(env, cont)
def rewind(self, env, cont):
from pycket.interpreter import return_void
return return_void(env, cont)
