def getslice_list(context, builder, sig, args):
inst = ListInstance(context, builder, sig.args[0], args[0])
slice = context.make_helper(builder, sig.args[1], args[1])
slicing.guard_invalid_slice(context, builder, sig.args[1], slice)
inst.fix_slice(slice)
# Allocate result and populate it
result_size = slicing.get_slice_length(builder, slice)
result = ListInstance.allocate(context, builder, sig.return_type,
result_size)
result.size = result_size
with cgutils.for_range_slice_generic(builder, slice.start, slice.stop,
slice.step) as (pos_range, neg_range):
with pos_range as (idx, count):
value = inst.getitem(idx)
result.inititem(count, value, incref=True)
with neg_range as (idx, count):
value = inst.getitem(idx)
result.inititem(count, value, incref=True)
return impl_ret_new_ref(context, builder, sig.return_type, result.value)
def setitem_list(context, builder, sig, args):
dest = ListInstance(context, builder, sig.args[0], args[0])
src = ListInstance(context, builder, sig.args[2], args[2])
slice = context.make_helper(builder, sig.args[1], args[1])
slicing.guard_invalid_slice(context, builder, sig.args[1], slice)
dest.fix_slice(slice)
src_size = src.size
avail_size = slicing.get_slice_length(builder, slice)
size_delta = builder.sub(src.size, avail_size)
zero = ir.Constant(size_delta.type, 0)
one = ir.Constant(size_delta.type, 1)
with builder.if_else(builder.icmp_signed('==', slice.step,
one)) as (then, otherwise):
with then:
# Slice step == 1 => we can resize
# Compute the real stop, e.g. for dest[2:0] = [...]
real_stop = builder.add(slice.start, avail_size)
# Size of the list tail, after the end of slice
tail_size = builder.sub(dest.size, real_stop)
with builder.if_then(builder.icmp_signed('>', size_delta, zero)):
# Grow list then move list tail
dest.resize(builder.add(dest.size, size_delta))
dest.move(builder.add(real_stop, size_delta), real_stop,
tail_size)
with builder.if_then(builder.icmp_signed('<', size_delta, zero)):
# Move list tail then shrink list
dest.move(builder.add(real_stop, size_delta), real_stop,
tail_size)
dest.resize(builder.add(dest.size, size_delta))
dest_offset = slice.start
with cgutils.for_range(builder, src_size) as loop:
value = src.getitem(loop.index)
dest.setitem(builder.add(loop.index, dest_offset),
value,
incref=True)
with otherwise:
with builder.if_then(builder.icmp_signed('!=', size_delta, zero)):
msg = "cannot resize extended list slice with step != 1"
context.call_conv.return_user_exc(builder, ValueError, (msg, ))
with cgutils.for_range_slice_generic(builder, slice.start,
slice.stop,
slice.step) as (pos_range,
neg_range):
with pos_range as (index, count):
value = src.getitem(count)
dest.setitem(index, value, incref=True)
with neg_range as (index, count):
value = src.getitem(count)
dest.setitem(index, value, incref=True)
return context.get_dummy_value()