refs.shape

Module nustd.kv.refs.shape.

Virtuals shape reference: structured container backed by a virtuals View.

Field descent (ref.field / ref["field"]) is the blueprint's __getattr__ / __getitem__: it resolves the slot to the field's own virtuals ref (StrRef, IntRef, ...) with this ref as parent_ref, so navigation rides the substrate automatically.

Name	Sort	Call	Meaning
ShapeRef	`ref`	`ShapeRef(address, shape_type, view_type=None, parent_ref=None, owner_shape=None)`	A nested shape slot in KV storage: a fixed set of named fields.

ShapeRef

A nested shape slot in KV storage: a fixed set of named fields.

ShapeRef(address, shape_type, view_type=None, parent_ref=None, owner_shape=None)

Path nustd.kv.ShapeRef. Kind Ref, sort ref, cardinality scalar.

Descending by field name resolves the declared slot into that field's own ref, with this one as its parent, so a whole hierarchy is written as nested Shape classes and navigated with dots.

Notes

ref.field and ref["field"] are the same descent; the second is what to write when the field name is computed.
Fields carry their own types, so descent lands on a typed leaf ref or on another container ref, not on a plain value.
Nothing is created until a leaf underneath is written; the write then materializes every level along the way.
The mapping surface (keys, items, len) reads the stored fields, so it only sees the fields actually written.

Example

class Order(Shape):
    symbol = StrRef.slot()
class Portfolio(Shape):
    latest = ShapeRef.slot(Order)
run(Portfolio.latest.symbol.set("SOL"), ctx)

Inherited methods

From nu.forms.collections.abc.mapping.ReactiveMappingForm:

Call	Builds	Meaning
`.on_change()`	`object`	Subscribe to any change on this mapping slot.

From nu.forms.collections.abc.mapping.MutableMappingForm:

Call	Builds	Meaning
`.set_item(key, value)`	`Any`	Set the value at key, inserting the key if it's missing: mapping[key] = value.
`.del_item(key)`	`Any`	Delete the entry at key: del mapping[key].
`.update(other)`	`Any`	Write other's entries into self, in place: mapping.update(other).
`.pop(key, default=None)`	`ValueResultT`	Remove key and yield its value, or default if key is missing.
`.popitem()`	`ValueResultT`	Remove and yield an arbitrary (key, value) pair: mapping.popitem().
`.setdefault(key, default=None)`	`ValueResultT`	Value at key, inserting default there first if key is missing.
`.merge_update(other)`	`CollectionResultT`	Merge other into self in place, and yield self: mapping \|= other.
`.clear()`	`Any`	Remove all entries: mapping.clear().

From nu.domains.shape.refs.shape.ShapeRef:

Call	Builds	Meaning
`a[key]`	`StructuredRef`	Navigate into shape slots via bracket access; mirror of getattr.

From nu.forms.collections.abc.mapping.MappingForm:

Call	Builds	Meaning
`.keys()`	`CollectionResultT`	All keys of the mapping: mapping.keys().
`.values()`	`CollectionResultT`	All values of the mapping: mapping.values().
`.items()`	`CollectionResultT`	All (key, value) pairs of the mapping: mapping.items().
`.get_item(key, default=None)`	`ValueResultT`	Value at key, falling back to default: mapping.get_item(key, default).
`.copy()`	`CollectionResultT`	Shallow copy of self: mapping.copy().
`.reversed_keys()`	`CollectionResultT`	Keys in reverse insertion order: reversed(mapping).
`.reversed_values()`	`CollectionResultT`	Values in reverse insertion order: reversed(mapping.values()).
`.reversed_items()`	`CollectionResultT`	(key, value) pairs in reverse insertion order: reversed(mapping.items()).
`.merge(other)`	`CollectionResultT`	Self and other merged into a new mapping: mapping \| other.

From nu.forms.collections.abc.collection.CollectionForm:

Call	Builds	Meaning
`.extract()`	`object`	Materialise the full subtree rooted at self.

From nu.forms.collections.abc.sized.SizedForm:

Call	Builds	Meaning
`.len()`	`Int`	Length of self.

From nu.forms.collections.abc.iterable.IterableForm:

Call	Builds	Meaning
`iter(a)`	`Iterator[ElementT]`	Open self into a lazy iterator stream (Python's `iter`).

From nu.forms.collections.abc.container.ContainerForm:

Call	Builds	Meaning
`.contains(item)`	`Bool`	Whether item is a member of self.

From nu.domains.shape.forms.collection.ReactiveCollectionForm:

Call	Builds	Meaning
`.on_child_change(address)`	`OnChildChange`	Observe changes at a specific child address.
`.on_children_change()`	`OnChildrenChange`	Observe changes across all direct children.
`.on_descendants_change()`	`OnDescendantsChange`	Observe changes across descendants matching `pattern`.

From nu.domains.shape.forms.collection.MutableCollectionForm:

Call	Builds	Meaning
`.set(value)`	`SetCmd`	Build a `SetCmd`.
`.erase()`	`Erase`	Build an `Erase`.
`.init(value)`	`IfDo`	Set `value` iff the collection is currently missing.

From nu.domains.shape.forms.collection.CollectionForm:

Call	Builds	Meaning
`.exists()`	`Exists`	Build an `Exists` query.
`.missing()`	`Missing`	Build a `Missing` query.

From nu.lang.forms.Form:

Call	Builds	Meaning
`.is_empty()`	`Bool`	True if this Form yields the EMPTY sentinel.
`.is_invalid()`	`Bool`	True if this Form yields the INVALID sentinel.
`.is_sentinel()`	`Bool`	True if this Form yields either sentinel (EMPTY or INVALID).
`.not_empty()`	`Bool`	True if this Form does not yield EMPTY.
`.not_invalid()`	`Bool`	True if this Form does not yield INVALID.

refs.shape

ShapeRef

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