AttachmentGetting

class dsviper.AttachmentGetting

Bases: object

Read access to the documents attached to a set of keys.

keys, has, get, enumerate, and diff_keys against another state.

Note: Not directly instantiable.

attachment(attachment_runtime_id: ValueUUId) → Attachment

Return the attachment attachment_runtime_id names, or raise if the definitions hold none.

definitions() → DefinitionsConst

Return the Definitions every value reachable here is typed by.

static diff_keys(current_attachment_getting: AttachmentGetting, other_attachment_getting: AttachmentGetting, attachment: Attachment) → tuple[ValueSet, ValueSet, ValueSet, ValueSet]

Return the tuple (added_keys, removed_keys, different_keys, same_keys).

Computed for attachment, between current_attachment_getting and other_attachment_getting.

• added_keys: keys present in ‘other’ and not in ‘current’.

• removed_keys: keys present in ‘current’ and not in ‘other’.

• different_keys: documents present in both but not equal.

• same_keys: documents present in both and equal.

enumerate(attachment: Attachment, *, encoded: Literal[True] = True) → list[tuple[ValueKey, _OutputValues]]

Return every (key, document) pair attachment holds.

encoded=False returns each document as a Value rather than a native object.

get(attachment: Attachment, key: ValueKey) → ValueOptional

Return a ValueOptional over the document attachment holds at key.

Always a ValueOptional, never None: ask is_nil() whether it holds anything, and unwrap() for the document itself.

An absent document answers a nil ValueOptional; a key of another concept than the one attachment files raises, so is_nil() reports absence and never a mismatched key.

The document comes back as a copy; mutating it does not reach what is stored.

has(attachment: Attachment, key: ValueKey) → bool

Return True if attachment holds a document at key.

keys(attachment: Attachment) → ValueSet

Return every key attachment holds a document for.

The set is taken now: a later write does not reach it.