Struct RunnerSnapshot 

pub struct RunnerSnapshot {
    pub current_node: Option<String>,
    pub visits: HashMap<String, u32>,
    pub once_seen: HashSet<String>,
}

A point-in-time snapshot of the dialogue session’s mutable state.

Use Runner::snapshot to capture and Runner::restore to apply.

The snapshot records:

• which node was active (current_node),
• how many times each node has been visited (visits),
• which <<once>> blocks have already fired (once_seen).

Variable storage is not included - it is the host’s responsibility to persist HashMapStorage (or their own VariableStorage impl) alongside the snapshot when building a full save file.

With the serde feature, this type also derives Serialize / Deserialize so you can write it to disk as JSON or another format.

Save / load example

Both the snapshot and variable storage must be serialised together when you persist to disk. Neither is complete without the other.

use bubbles::{HashMapStorage, Runner, Value, VariableStorage, compile};

let src = "title: A\n---\n<<set $gold = 10>>\nHello!\n===\n";
let prog = compile(src).unwrap();

// First session
let mut runner = Runner::new(prog.clone(), HashMapStorage::new());
runner.start("A").unwrap();
let _ = runner.next_event(); // NodeStarted
let _ = runner.next_event(); // (set $gold side-effect, then Line)

let snap = runner.snapshot();
let snap_json = serde_json::to_string(&snap).unwrap();
let vars_json = serde_json::to_string(runner.storage()).unwrap();

let saved_vars: HashMapStorage = serde_json::from_str(&vars_json).unwrap();
let saved_snap: bubbles::RunnerSnapshot = serde_json::from_str(&snap_json).unwrap();

let mut runner2 = Runner::new(prog, saved_vars);
runner2.restore(saved_snap).unwrap();
// runner2 is back at the beginning of node "A" with $gold already set.

Fields

current_node: Option<String>

The node that was executing when the snapshot was taken.

When restoring, Runner::restore will restart execution from the beginning of this node. This is intentional: the in-progress statement list is not serialised because it would require the full AST to be round-tripped.

visits: HashMap<String, u32>

How many times each node has been visited.

once_seen: HashSet<String>

IDs of <<once>> blocks (and once-line-variants) that have already fired and must not fire again.

Trait Implementations

impl Clone for RunnerSnapshot

fn clone(&self) -> RunnerSnapshot

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RunnerSnapshot

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for RunnerSnapshot

fn eq(&self, other: &RunnerSnapshot) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for RunnerSnapshot

impl StructuralPartialEq for RunnerSnapshot