refs.listshape

Module nustd.mem.refs.listshape.

Dict shapes list reference: sequence of homogeneous shapes.

Index descent (ref[i]) is the blueprint's __getitem__: it returns a ShapeRef at the index with this ref as parent_ref. The element shape type is passed to the blueprint as item_shape_type.

Name	Sort	Call	Meaning
ShapesListRef	`ref`	`ShapesListRef(address, shape_type, parent_ref=None, owner_shape=None)`	A list of one Shape's records, stored as a plain list of inner dicts.

ShapesListRef

A list of one Shape's records, stored as a plain list of inner dicts.

ShapesListRef(address, shape_type, parent_ref=None, owner_shape=None)

Path nustd.mem.ShapesListRef. Kind Ref, sort ref, cardinality scalar.

Subscripting descends: ref[i] is a ShapeRef at that index holding the element Shape, so rows[0].symbol is a full path down to a leaf and nothing is read until the whole chain runs.

Notes

Elements are plain dicts, so a record is appended by appending a dict, not a Shape instance.
In-place calls read the container first and do nothing when the slot is absent, so set an empty list before the first append.
An index past the end reads EMPTY rather than raising, like any other broken path.

Example

class Order(nu.Shape):
    symbol = nustd.mem.StrRef.slot()
class Book(nu.Shape):
    rows = nustd.mem.ShapesListRef.slot(Order)
ctx = nu.Context().bind(dict, {"rows": [{"symbol": "AAPL"}]}, Book)
nu.run(Book.rows[0].symbol, ctx)[0]

'AAPL'

Inherited methods

From nu.forms.collections.abc.sequence.MutableSequenceForm:

Call	Builds	Meaning
`.append(value)`	`Any`	Append value to the end of self.
`.extend(other)`	`Any`	Extend self with the elements of other, in order.
`.insert(index, value)`	`Any`	Insert value at index, shifting later elements right.
`.pop(index=-1)`	`ElementResultT`	Remove and return the element at index.
`.del_at(index)`	`Any`	Remove the element at index.
`.remove(value)`	`Any`	Remove the first occurrence of value.
`.reverse()`	`Any`	Reverse self in place.
`.sort()`	`Any`	Sort self in place, ascending, using the elements' natural order.
`.copy()`	`CollectionResultT`	Shallow copy of self: a new sequence with the same elements.
`.clear()`	`Any`	Remove every element from self.

From nu.domains.shape.refs.shapes_sequence.ShapesSequenceRef:

Call	Builds	Meaning
`a[key]`	`ItemResultT`	Int index navigates to the child ShapeRef; slice routes to the form-level slice op.

From nu.forms.collections.abc.sequence.SequenceForm:

Call	Builds	Meaning
`.first_elem()`	`ElementResultT`	First element of self.
`.last_elem()`	`ElementResultT`	Last element of self.
`.index(value)`	`Int`	Lowest index in self where value is found, searching from the left.
`.count(value)`	`Int`	Count of occurrences of value in self.
`.reversed()`	`CollectionResultT`	Self walked back to front, as a stream.

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.forms.collections.abc.sliceable.SliceableForm:

Call	Builds	Meaning
`.slice(start, stop, step=None)`	`ResultT`	Slice of self from start to stop, stepping by step.

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.listshape

ShapesListRef

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