def compile_shape(ir_set: irast.Set, shape: List[Tuple[irast.Set,
qlast.ShapeOp]], *,
ctx: context.CompilerContextLevel) -> pgast.TupleVar:
elements = []
with ctx.newscope() as shapectx:
shapectx.disable_semi_join.add(ir_set.path_id)
if isinstance(ir_set.expr, irast.Stmt):
# The source set for this shape is a FOR statement,
# which is special in that besides set path_id it
# should also expose the path_id of the FOR iterator
# so that shape element expressions that might contain
# an iterator reference find it properly.
#
# So, for:
# SELECT Bar {
# foo := (FOR x := ... UNION Foo { spam := x })
# }
#
# the path scope when processing the shape of Bar.foo
# should be {'Bar.foo', 'x'}.
iterator = ir_set.expr.iterator_stmt
if iterator:
shapectx.path_scope[iterator.path_id] = ctx.rel
for el, _ in shape:
rptr = el.rptr
assert rptr is not None
ptrref = rptr.ptrref
is_singleton = ptrref.dir_cardinality.is_single()
value: pgast.BaseExpr
if (irutils.is_subquery_set(el) or el.path_id.is_objtype_path()
or not is_singleton or not ptrref.required):
wrapper = relgen.set_as_subquery(el,
as_value=True,
ctx=shapectx)
if not is_singleton:
value = relgen.set_to_array(ir_set=el,
query=wrapper,
ctx=shapectx)
else:
value = wrapper
else:
value = dispatch.compile(el, ctx=shapectx)
tuple_el = astutils.tuple_element_for_shape_el(el,
value,
ctx=shapectx)
assert isinstance(tuple_el, pgast.TupleElement)
elements.append(tuple_el)
return pgast.TupleVar(elements=elements, named=True)
def compile_shape(ir_set: irast.Set, shape: Sequence[Tuple[irast.Set,
qlast.ShapeOp]], *,
ctx: context.CompilerContextLevel) -> pgast.TupleVar:
elements = []
# If the object identity is potentially nullable, filter it out
# to prevent shapes with bogusly null insides.
var = pathctx.get_path_value_var(ctx.rel,
path_id=ir_set.path_id,
env=ctx.env)
if var.nullable:
ctx.rel.where_clause = astutils.extend_binop(
ctx.rel.where_clause, pgast.NullTest(arg=var, negated=True))
with ctx.newscope() as shapectx:
shapectx.disable_semi_join |= {ir_set.path_id}
if isinstance(ir_set.expr, irast.Stmt):
# The source set for this shape is a FOR statement,
# which is special in that besides set path_id it
# should also expose the path_id of the FOR iterator
# so that shape element expressions that might contain
# an iterator reference find it properly.
#
# So, for:
# SELECT Bar {
# foo := (FOR x := ... UNION Foo { spam := x })
# }
#
# the path scope when processing the shape of Bar.foo
# should be {'Bar.foo', 'x'}.
iterator = ir_set.expr.iterator_stmt
if iterator:
shapectx.path_scope[iterator.path_id] = ctx.rel
for el, op in shape:
if op == qlast.ShapeOp.MATERIALIZE and not ctx.materializing:
continue
rptr = el.rptr
assert rptr is not None
ptrref = rptr.ptrref
# As an implementation expedient, we currently represent
# AT_MOST_ONE materialized values with arrays
card = rptr.dir_cardinality
is_singleton = (card.is_single() and
(not ctx.materializing or not card.can_be_zero()))
value: pgast.BaseExpr
if (irutils.is_subquery_set(el) or el.path_id.is_objtype_path()
or not is_singleton or not ptrref.required):
wrapper = relgen.set_as_subquery(el,
as_value=True,
ctx=shapectx)
if not is_singleton:
value = relctx.set_to_array(path_id=el.path_id,
query=wrapper,
ctx=shapectx)
else:
value = wrapper
else:
value = dispatch.compile(el, ctx=shapectx)
tuple_el = astutils.tuple_element_for_shape_el(el,
value,
ctx=shapectx)
assert isinstance(tuple_el, pgast.TupleElement)
elements.append(tuple_el)
return pgast.TupleVar(elements=elements, named=True)