def type_intersection_set(
source_set: irast.Set,
stype: s_types.Type,
*,
optional: bool,
ctx: context.ContextLevel,
) -> irast.Set:
"""Return an interesection of *source_set* with type *stype*."""
arg_type = get_set_type(source_set, ctx=ctx)
result = schemactx.apply_intersection(arg_type, stype, ctx=ctx)
if result.stype is arg_type:
return source_set
poly_set = new_set(stype=result.stype, ctx=ctx)
rptr = source_set.rptr
rptr_specialization = []
if rptr is not None and rptr.ptrref.union_components:
# This is a type intersection of a union pointer, most likely
# a reverse link path specification. If so, test the union
# components against the type expression and record which
# components match. This information will be used later
# when evaluating the path cardinality, as well as to
# route link property references accordingly.
for component in rptr.ptrref.union_components:
component_endpoint_ref = component.dir_target
ctx.env.schema, component_endpoint = irtyputils.ir_typeref_to_type(
ctx.env.schema, component_endpoint_ref)
if component_endpoint.issubclass(ctx.env.schema, stype):
assert isinstance(component, irast.PointerRef)
rptr_specialization.append(component)
ptrcls = irast.TypeIntersectionLink(
arg_type,
result.stype,
optional=optional,
is_empty=result.is_empty,
is_subtype=result.is_subtype,
rptr_specialization=rptr_specialization,
# The type intersection cannot increase the cardinality
# of the input set, so semantically, the cardinality
# of the type intersection "link" is, at most, ONE.
cardinality=qltypes.SchemaCardinality.ONE,
)
ptrref = irtyputils.ptrref_from_ptrcls(
schema=ctx.env.schema,
ptrcls=ptrcls,
cache=ctx.env.ptr_ref_cache,
typeref_cache=ctx.env.type_ref_cache,
)
poly_set.path_id = source_set.path_id.extend(
schema=ctx.env.schema,
ptrref=ptrref,
)
ptr = irast.TypeIntersectionPointer(
source=source_set,
target=poly_set,
ptrref=ptrref,
direction=poly_set.path_id.rptr_dir(),
optional=optional,
)
poly_set.rptr = ptr
return poly_set
def computable_ptr_set(
rptr: irast.Pointer, *,
unnest_fence: bool=False,
same_computable_scope: bool=False,
from_default_expr: bool=False,
ctx: context.ContextLevel) -> irast.Set:
"""Return ir.Set for a pointer defined as a computable."""
ptrcls = irtyputils.ptrcls_from_ptrref(rptr.ptrref, schema=ctx.env.schema)
source_set = rptr.source
source_scls = get_set_type(source_set, ctx=ctx)
# process_view() may generate computable pointer expressions
# in the form "self.linkname". To prevent infinite recursion,
# self must resolve to the parent type of the view NOT the view
# type itself. Similarly, when resolving computable link properties
# make sure that we use ptrcls.derived_from.
if source_scls.is_view(ctx.env.schema):
source_set_stype = source_scls.peel_view(ctx.env.schema)
source_set = new_set_from_set(
source_set, stype=source_set_stype,
preserve_scope_ns=True, ctx=ctx)
source_set.shape = []
if source_set.rptr is not None:
schema = ctx.env.schema
source_rptrref = source_set.rptr.ptrref
source_rptrcls = irtyputils.ptrcls_from_ptrref(
source_rptrref, schema=schema)
bases = source_rptrcls.get_bases(schema)
if bases:
base = bases.first(schema)
if (not base.generic(schema)
and ptrcls.is_link_property(schema)):
source_rptrref = irtyputils.ptrref_from_ptrcls(
source_ref=source_rptrref.dir_source,
target_ref=source_rptrref.dir_target,
direction=source_rptrref.direction,
parent_ptr=source_rptrref.parent_ptr,
ptrcls=base,
schema=schema,
)
source_set.rptr = irast.Pointer(
source=source_set.rptr.source,
target=source_set,
ptrref=source_rptrref,
direction=source_set.rptr.direction,
)
stmtctx.ensure_ptrref_cardinality(
base, source_set.rptr.ptrref, ctx=ctx)
qlctx: typing.Optional[context.ContextLevel]
inner_source_path_id: typing.Optional[irast.PathId]
try:
qlexpr, qlctx, inner_source_path_id, path_id_ns = \
ctx.source_map[ptrcls]
except KeyError:
if from_default_expr:
comp_expr = ptrcls.get_default(ctx.env.schema)
else:
comp_expr = ptrcls.get_expr(ctx.env.schema)
if comp_expr is None:
ptrcls_sn = ptrcls.get_shortname(ctx.env.schema)
raise ValueError(
f'{ptrcls_sn!r} is not a computable pointer')
qlexpr = qlparser.parse(comp_expr.text)
# NOTE: Validation of the expression type is not the concern
# of this function. For any non-object pointer target type,
# the default expression must be assignment-cast into that
# type.
target_scls = ptrcls.get_target(ctx.env.schema)
assert target_scls is not None
if not target_scls.is_object_type():
qlexpr = qlast.TypeCast(
type=astutils.type_to_ql_typeref(
target_scls, schema=ctx.env.schema),
expr=qlexpr,
)
qlexpr = astutils.ensure_qlstmt(qlexpr)
qlctx = None
inner_source_path_id = None
path_id_ns = None
if qlctx is None:
# Schema-level computable, completely detached context
newctx = ctx.detached
else:
newctx = _get_computable_ctx(
rptr=rptr,
source=source_set,
source_scls=source_scls,
inner_source_path_id=inner_source_path_id,
path_id_ns=path_id_ns,
same_scope=same_computable_scope,
qlctx=qlctx,
ctx=ctx)
if ptrcls.is_link_property(ctx.env.schema):
source_path_id = rptr.source.path_id.ptr_path()
else:
source_path_id = rptr.target.path_id.src_path()
result_stype = ptrcls.get_target(ctx.env.schema)
result_path_id = pathctx.extend_path_id(
source_path_id,
ptrcls=ptrcls,
direction=s_pointers.PointerDirection.Outbound,
target=result_stype,
ns=ctx.path_id_namespace,
ctx=ctx)
with newctx() as subctx:
subctx.view_scls = result_stype
subctx.view_rptr = context.ViewRPtr(
source_scls, ptrcls=ptrcls, rptr=rptr)
subctx.anchors[qlast.Source] = source_set
subctx.empty_result_type_hint = ptrcls.get_target(ctx.env.schema)
subctx.partial_path_prefix = source_set
if isinstance(qlexpr, qlast.Statement) and unnest_fence:
subctx.stmt_metadata[qlexpr] = context.StatementMetadata(
is_unnest_fence=True)
comp_ir_set = ensure_set(
dispatch.compile(qlexpr, ctx=subctx), ctx=subctx)
comp_ir_set_copy = new_set_from_set(comp_ir_set, ctx=ctx)
pending_cardinality = ctx.pending_cardinality.get(ptrcls)
if pending_cardinality is not None and not pending_cardinality.from_parent:
stmtctx.get_pointer_cardinality_later(
ptrcls=ptrcls, irexpr=comp_ir_set_copy,
specified_card=pending_cardinality.specified_cardinality,
source_ctx=pending_cardinality.source_ctx,
ctx=ctx)
stmtctx.enforce_pointer_cardinality(ptrcls, comp_ir_set_copy, ctx=ctx)
comp_ir_set = new_set_from_set(
comp_ir_set, path_id=result_path_id, rptr=rptr, ctx=ctx)
rptr.target = comp_ir_set
return comp_ir_set
def computable_ptr_set(rptr: irast.Pointer,
*,
unnest_fence: bool = False,
same_computable_scope: bool = False,
ctx: context.ContextLevel) -> irast.Set:
"""Return ir.Set for a pointer defined as a computable."""
ptrcls = irtyputils.ptrcls_from_ptrref(rptr.ptrref, schema=ctx.env.schema)
source_set = rptr.source
source_scls = get_set_type(source_set, ctx=ctx)
# process_view() may generate computable pointer expressions
# in the form "self.linkname". To prevent infinite recursion,
# self must resolve to the parent type of the view NOT the view
# type itself. Similarly, when resolving computable link properties
# make sure that we use ptrcls.derived_from.
if source_scls.is_view(ctx.env.schema):
source_set_stype = source_scls.peel_view(ctx.env.schema)
source_set = new_set_from_set(source_set,
stype=source_set_stype,
preserve_scope_ns=True,
ctx=ctx)
source_set.shape = []
if source_set.rptr is not None:
schema = ctx.env.schema
source_rptrref = source_set.rptr.ptrref
source_rptrcls = irtyputils.ptrcls_from_ptrref(source_rptrref,
schema=schema)
derived_from = source_rptrcls.get_derived_from(schema)
if (derived_from is not None and not derived_from.generic(schema)
and derived_from.get_derived_from(schema) is not None
and ptrcls.is_link_property(schema)):
source_set.rptr.ptrref = irtyputils.ptrref_from_ptrcls(
source_ref=source_rptrref.dir_source,
target_ref=source_rptrref.dir_target,
direction=source_rptrref.direction,
parent_ptr=source_rptrref.parent_ptr,
ptrcls=derived_from,
schema=schema,
)
stmtctx.ensure_ptrref_cardinality(derived_from,
source_set.rptr.ptrref,
ctx=ctx)
try:
qlexpr, qlctx, inner_source_path_id, path_id_ns = \
ctx.source_map[ptrcls]
except KeyError:
ptrcls_default = ptrcls.get_default(ctx.env.schema)
if not ptrcls_default:
ptrcls_sn = ptrcls.get_shortname(ctx.env.schema)
raise ValueError(f'{ptrcls_sn!r} is not a computable pointer')
qlexpr = astutils.ensure_qlstmt(qlparser.parse(ptrcls_default.text))
qlctx = None
inner_source_path_id = None
path_id_ns = None
if qlctx is None:
# Schema-level computable, completely detached context
newctx = ctx.detached
else:
newctx = _get_computable_ctx(rptr=rptr,
source=source_set,
source_scls=source_scls,
inner_source_path_id=inner_source_path_id,
path_id_ns=path_id_ns,
same_scope=same_computable_scope,
qlctx=qlctx,
ctx=ctx)
if ptrcls.is_link_property(ctx.env.schema):
source_path_id = rptr.source.path_id.ptr_path()
else:
source_path_id = rptr.target.path_id.src_path()
result_stype = ptrcls.get_target(ctx.env.schema)
result_path_id = pathctx.extend_path_id(
source_path_id,
ptrcls=ptrcls,
direction=s_pointers.PointerDirection.Outbound,
target=result_stype,
ns=ctx.path_id_namespace,
ctx=ctx)
with newctx() as subctx:
subctx.view_scls = result_stype
subctx.view_rptr = context.ViewRPtr(source_scls,
ptrcls=ptrcls,
rptr=rptr)
subctx.anchors[qlast.Source] = source_set
subctx.empty_result_type_hint = ptrcls.get_target(ctx.env.schema)
subctx.partial_path_prefix = source_set
if isinstance(qlexpr, qlast.Statement) and unnest_fence:
subctx.stmt_metadata[qlexpr] = context.StatementMetadata(
is_unnest_fence=True)
comp_ir_set = dispatch.compile(qlexpr, ctx=subctx)
pending_cardinality = ctx.pending_cardinality.get(ptrcls)
if pending_cardinality is not None and not pending_cardinality.from_parent:
comp_ir_set_copy = new_set_from_set(comp_ir_set, ctx=ctx)
stmtctx.get_pointer_cardinality_later(
ptrcls=ptrcls,
irexpr=comp_ir_set_copy,
specified_card=pending_cardinality.specified_cardinality,
source_ctx=pending_cardinality.source_ctx,
ctx=ctx)
def _check_cardinality(ctx):
if ptrcls.singular(ctx.env.schema):
stmtctx.enforce_singleton_now(comp_ir_set_copy, ctx=ctx)
stmtctx.at_stmt_fini(_check_cardinality, ctx=ctx)
comp_ir_set = new_set_from_set(comp_ir_set,
path_id=result_path_id,
rptr=rptr,
ctx=ctx)
rptr.target = comp_ir_set
return comp_ir_set
