Struct DbDir 

pub struct DbDir { /* private fields */ }

A node in a path-addressed, capability-gated directory tree of symbol-keyed values.

This is an in-memory table/directory backend, not an external database engine: every DbDir is a view onto a shared store (a BTreeMap of values and a BTreeSet of directory paths behind a Mutex) rooted at a particular path. As a Table it reads and writes the values at its own path; as a Dir it creates, opens, and removes child directories, each of which is another DbDir sharing the same store. Cloning a DbDir shares the underlying store. Every operation requires the relevant table/db capability (read, write, mkdir, or rmdir), and child names must be legal single path segments.

Implementations

impl DbDir

pub fn open() -> Self

Open a fresh store and return a DbDir rooted at its top-level directory.

Trait Implementations

impl Citizen for DbDir

fn citizen_symbol() -> Symbol

The citizen’s namespace/name class symbol.

fn citizen_version() -> u32

The citizen’s encoding version.

fn citizen_arity() -> usize

Number of constructor fields (excluding the version argument).

fn citizen_fields() -> &'static [&'static str]

The citizen’s field names, in constructor order.

impl Clone for DbDir

fn clone(&self) -> DbDir

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for DbDir

fn default() -> Self

Returns the “default value” for a type.

impl Dir for DbDir

fn mkdir(&self, cx: &mut Cx, name: Symbol) -> Result<Value>

Creates a nested subtable under name, returning it.

fn opendir(&self, cx: &mut Cx, name: Symbol) -> Result<Option<Value>>

Opens the subtable at name, or Ok(None) when absent.

fn rmdir(&self, cx: &mut Cx, name: Symbol) -> Result<Value>

Removes the subtable at name, returning it.

fn is_dir(&self, cx: &mut Cx, name: Symbol) -> Result<bool>

Whether name resolves to a subtable.

impl Object for DbDir

fn display(&self, _cx: &mut Cx) -> Result<String>

Render the object as a human-readable display string.

fn as_any(&self) -> &dyn Any

Expose the object for Rust downcasting.

fn header(&self) -> &ObjectHeader

Identity and trust header for the object; defaults to the shared anonymous header.

fn op(&self, _key: &OpKey) -> Option<&dyn Op>

Resolve the operation registered under key, if any.

fn claims( &self, _cx: &mut Cx, _pattern: &ClaimPattern, _sink: &mut dyn ClaimSink, ) -> Result<(), Error>

Emit the object’s claims matching pattern into sink.

fn snapshot(&self, _cx: &mut Cx) -> Result<Option<Datum>, Error>

Optional content-addressable snapshot of the object’s state.

impl ObjectCompat for DbDir

fn class(&self, cx: &mut Cx) -> Result<ClassRef>

Class object this value belongs to; defaults to nil.

fn as_expr(&self, cx: &mut Cx) -> Result<Expr>

Expression form of the object; defaults to an opaque extension node.

fn truth(&self, cx: &mut Cx) -> Result<bool>

Truthiness of the object; defaults to true.

fn as_table_impl(&self) -> Option<&dyn Table>

Table-implementation view, if the object is a table.

fn as_dir(&self) -> Option<&dyn Dir>

Directory view, if the object is a directory.

fn as_object_encoder(&self) -> Option<&dyn ObjectEncode>

Object-encoder view, if the object encodes other objects.

fn as_callable(&self) -> Option<&dyn Callable>

Callable view, if the object can be invoked.

fn as_class(&self) -> Option<&dyn Class>

Class view, if the object is a class.

fn as_shape(&self) -> Option<&dyn Shape>

Shape view, if the object is a shape.

fn as_read_constructor(&self) -> Option<&dyn ReadConstructor>

Read-constructor view, if the object decodes data forms.

fn as_number_domain(&self) -> Option<&(dyn NumberDomain + 'static)>

Number-domain view, if the object is a number domain.

fn as_number_value(&self) -> Option<&dyn NumberValue>

Number-value view, if the object is a domain number.

fn as_eval_fabric(&self) -> Option<&dyn EvalFabric>

Eval-fabric view, if the object is a distributed eval surface.

fn as_stream(&self) -> Option<&dyn Stream>

Stream view, if the object is a stream.

fn as_sequence(&self) -> Option<&dyn Sequence>

Sequence view, if the object is a sequence.

fn as_thunk(&self) -> Option<&dyn Thunk>

Thunk view, if the object is a deferred computation.

fn as_list(&self) -> Option<&(dyn ListValue + 'static)>

List view, if the object is a list value.

fn publish_shape_satisfaction_claims( &self, _cx: &mut Cx, _shape: &Ref, ) -> Result<bool, Error>

Publish claims asserting that the object satisfies shape; returns whether any were published.

fn as_table(&self, cx: &mut Cx) -> Result<Value, Error>

Project the object into a table value; the default exposes its display.

impl ObjectEncode for DbDir

fn object_encoding(&self, _cx: &mut Cx) -> Result<ObjectEncoding>

Returns the ObjectEncoding this object should be rendered as.

impl Table for DbDir

fn backend_symbol(&self) -> Symbol

Symbol identifying the backend representation.

fn get(&self, cx: &mut Cx, key: Symbol) -> Result<Value>

Looks up key, returning nil when absent.

fn set(&self, cx: &mut Cx, key: Symbol, value: Value) -> Result<()>

Inserts or replaces the value for key.

fn has(&self, cx: &mut Cx, key: Symbol) -> Result<bool>

Whether key is present.

fn del(&self, cx: &mut Cx, key: Symbol) -> Result<Value>

Removes key, returning its prior value or nil.

fn keys(&self, cx: &mut Cx) -> Result<Vec<Symbol>>

All keys, in backend order.

fn entries(&self, cx: &mut Cx) -> Result<Vec<(Symbol, Value)>>

All key/value pairs, in backend order.

fn len(&self, cx: &mut Cx) -> Result<usize>

Number of entries.

fn clear(&self, cx: &mut Cx) -> Result<()>

Removes all entries.

fn is_empty(&self, cx: &mut Cx) -> Result<bool, Error>

Whether the table has no entries.

fn as_table_expr(&self, cx: &mut Cx) -> Result<Expr, Error>

Projects the table to an Expr::Map.

fn table_eq( &self, cx: &mut Cx, other: &(dyn Table + 'static), ) -> Result<bool, Error>

Order-insensitive equality against another table’s entries.