Add backlinks to query builder

[dnwpark]

Object models now have a __backlinks__ field, which is set to a GelObjectBacklinksModel. This backlinks model contains multi links to std::BaseObject.

These new backlinks models are generated during reflection. At runtime, intersections generate a backlink model alongside the intersection type.

A simple query with backlinks:

default.Inh_A.__backlinks__.l
.is_(default.Link_Inh_A)
.select(n=True, l=True)

WITH baseobject_and_link_inh_a := (
    default::Inh_A.<l [is default::Link_Inh_A]
)
SELECT baseobject_and_link_inh_a {
    n,
    l := baseobject_and_link_inh_a.l { * },
}

A more complex query with backlinks:

default.Link_Inh_AB.l  # Link
.is_(default.Inh_AC)  # Intersection
.__backlinks__.l.is_(default.Link_Inh_A)  #  Backlink
.select(n=True, l=True)

WITH baseobject_and_link_inh_a := (
    (
        default::Link_Inh_AB.l [is default::Inh_AC]
    ).<l [is default::Link_Inh_A]
)
SELECT baseobject_and_link_inh_a {
    n,
    l := baseobject_and_link_inh_a.l { * },
}

Also works inside shapes:

default.Inh_AB.select(
    a=lambda x: x.__backlinks__.l.is_(default.Link_Inh_AB).limit(1).n
)

WITH inh_ab := default::Inh_AB
SELECT inh_ab {
    a := (
        SELECT (inh_ab.<l [is default::Link_Inh_AB]) { * }
        LIMIT 1
    ).n,
}

[msullivan]

This seems basically plausible; could you post some of the generated model code here?

[dnwpark]

In __sharedstd__/__shapes__/std/__init__.py

All other backlinks classes derive from __BaseObject_backlinks__:

class __BaseObject_backlinks__(GelObjectBacklinksModel):
    class __gel_reflection__(GelObjectBacklinksModel.__gel_reflection__):
        name = SchemaPath.from_segments('std', 'BaseObject')
        type_name = SchemaPath.from_segments('std', 'BaseObject')
        @LazyClassProperty["dict[builtins.str, GelPointerReflection]"]
        @classmethod
        def pointers(cls,) -> dict[builtins.str, GelPointerReflection]:
            my_ptrs: dict[builtins.str, GelPointerReflection] = {}
            return my_ptrs

Which is added to BaseObject:

class BaseObject(...):
    ...

    __backlinks__: GelObjectBacklinksModelDescriptor[__BaseObject_backlinks__] = GelObjectBacklinksModelDescriptor[__BaseObject_backlinks__]()

    ...

For user defined types, an object Inh_A with a backlink l:

class __Inh_A_backlinks__(std_shapes.__Object_backlinks__):
    class __gel_reflection__(
        std_shapes.__Object_backlinks__.__gel_reflection__
    ):
        name = SchemaPath.from_segments('default', 'Inh_A')
        type_name = SchemaPath.from_segments('default', 'Inh_A')
        @LazyClassProperty["dict[str, GelPointerReflection]"]
        @classmethod
        def pointers(cls,) -> dict[str, GelPointerReflection]:
            my_ptrs: dict[str, GelPointerReflection] = {
                'l': GelPointerReflection(
                    name='l',
                    type=std_shapes.BaseObject,
                    kind=PointerKind('Link'),
                    cardinality=Cardinality('Many'),
                    computed=True,
                    readonly=True,
                    has_default=False,
                    mutable=False,
                    properties=None,
                ),
            }
            return (
                my_ptrs
                | std_shapes.__Object_backlinks__.__gel_reflection__.pointers
            )

    l: ComputedMultiLink[std_shapes.BaseObject]

...

class Inh_A(...):
    __backlinks__: GelObjectBacklinksModelDescriptor[__Inh_A_backlinks__] = GelObjectBacklinksModelDescriptor[__Inh_A_backlinks__]()

    ...

[msullivan]

Great work!

[msullivan]

comment on why this is special?

[msullivan]

Maybe a name change here or a comment, but there is a bunch of code here dealing with both the base types of the current object and also BaseObject, and it's a little confusing