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)
def get_pointer_path_id(ptr: s_pointers.Pointer, *,
ctx: context.ContextLevel) -> irast.PathId:
src = ptr.get_source(ctx.env.schema)
assert isinstance(src, s_types.Type)
return extend_path_id(get_path_id(src, ctx=ctx), ptrcls=ptr, ctx=ctx)