def derive_ptr(ptr: s_pointers.Pointer,
source: s_sources.Source,
target: Optional[s_types.Type] = None,
*qualifiers: str,
derived_name: Optional[sn.SchemaName] = None,
derived_name_quals: Optional[Sequence[str]] = (),
derived_name_base: Optional[str] = None,
preserve_shape: bool = False,
preserve_path_id: bool = False,
is_insert: bool = False,
is_update: bool = False,
inheritance_merge: bool = True,
attrs: Optional[Dict[str, Any]] = None,
ctx: context.ContextLevel) -> s_pointers.Pointer:
if derived_name is None and ctx.derived_target_module:
derived_name = derive_view_name(stype=ptr,
derived_name_quals=derived_name_quals,
derived_name_base=derived_name_base,
ctx=ctx)
if ptr.get_name(ctx.env.schema) == derived_name:
qualifiers = qualifiers + (ctx.aliases.get('d'), )
ctx.env.schema, derived = ptr.derive_ref(
ctx.env.schema,
source,
*qualifiers,
target=target,
name=derived_name,
inheritance_merge=inheritance_merge,
inheritance_refdicts={'pointers'},
mark_derived=True,
transient=True,
preserve_path_id=preserve_path_id,
attrs=attrs)
if not ptr.generic(ctx.env.schema):
if isinstance(derived, s_sources.Source):
ptr = cast(s_links.Link, ptr)
scls_pointers = ptr.get_pointers(ctx.env.schema)
derived_own_pointers = derived.get_pointers(ctx.env.schema)
for pn, ptr in derived_own_pointers.items(ctx.env.schema):
# This is a view of a view. Make sure query-level
# computable expressions for pointers are carried over.
src_ptr = scls_pointers.get(ctx.env.schema, pn)
# mypy somehow loses the type argument in the
# "pointers" ObjectIndex.
assert isinstance(src_ptr, s_pointers.Pointer)
computable_data = ctx.source_map.get(src_ptr)
if computable_data is not None:
ctx.source_map[ptr] = computable_data
if preserve_shape and ptr in ctx.env.view_shapes:
ctx.env.view_shapes[derived] = ctx.env.view_shapes[ptr]
ctx.env.created_schema_objects.add(derived)
return derived
def derive_ptr(ptr: s_pointers.Pointer,
source: s_sources.Source,
target: typing.Optional[s_types.Type] = None,
*qualifiers,
derived_name: typing.Optional[sn.SchemaName] = None,
derived_name_quals: typing.Optional[typing.Sequence[str]] = (),
derived_name_base: typing.Optional[str] = None,
preserve_shape: bool = False,
preserve_path_id: bool = False,
is_insert: bool = False,
is_update: bool = False,
inheritance_merge: bool = True,
attrs: typing.Optional[dict] = None,
ctx: context.ContextLevel) -> s_pointers.Pointer:
if derived_name is None and ctx.derived_target_module:
derived_name = derive_view_name(stype=ptr,
derived_name_quals=derived_name_quals,
derived_name_base=derived_name_base,
ctx=ctx)
if ptr.get_name(ctx.env.schema) == derived_name:
qualifiers = qualifiers + (ctx.aliases.get('d'), )
ctx.env.schema, derived = ptr.derive_ref(
ctx.env.schema,
source,
target,
*qualifiers,
name=derived_name,
inheritance_merge=inheritance_merge,
refdict_whitelist={'pointers'},
mark_derived=True,
preserve_path_id=preserve_path_id,
attrs=attrs)
if not ptr.generic(ctx.env.schema):
if isinstance(derived, s_sources.Source):
ptr = typing.cast(s_links.Link, ptr)
scls_pointers = ptr.get_pointers(ctx.env.schema)
derived_own_pointers = derived.get_pointers(ctx.env.schema)
for pn, ptr in derived_own_pointers.items(ctx.env.schema):
# This is a view of a view. Make sure query-level
# computable expressions for pointers are carried over.
src_ptr = scls_pointers.get(ctx.env.schema, pn)
computable_data = ctx.source_map.get(src_ptr)
if computable_data is not None:
ctx.source_map[ptr] = computable_data
if preserve_shape and ptr in ctx.env.view_shapes:
ctx.env.view_shapes[derived] = ctx.env.view_shapes[ptr]
return derived
def from_pointer(
cls,
schema: s_schema.Schema,
pointer: s_pointers.Pointer,
*,
namespace: AbstractSet[AnyNamespace] = frozenset(),
) -> PathId:
"""Return a ``PathId`` instance for a given link or property.
The specified *pointer* argument must be a concrete link or property.
The returned ``PathId`` instance describes a set variable of all
objects represented by the pointer (i.e, for a link, a set of all
link targets).
Args:
schema:
A schema instance where the type *t* is defined.
pointer:
An instance of a concrete link or property.
namespace:
Optional namespace in which the variable is defined.
Returns:
A ``PathId`` instance.
"""
if pointer.generic(schema):
raise ValueError(f'invalid PathId: {pointer} is not concrete')
source = pointer.get_source(schema)
if isinstance(source, s_pointers.Pointer):
prefix = cls.from_pointer(schema, source, namespace=namespace)
prefix = prefix.ptr_path()
elif isinstance(source, s_types.Type):
prefix = cls.from_type(schema, source, namespace=namespace)
else:
raise AssertionError(f'unexpected pointer source: {source!r}')
ptrref = typeutils.ptrref_from_ptrcls(schema=schema, ptrcls=pointer)
return prefix.extend(ptrref=ptrref)