Struct HistoryBuilder 

pub struct HistoryBuilder { /* private fields */ }

Configuration for a History.

Construct via History::builder. Setters return Self so calls chain; build is infallible.

Implementations

impl HistoryBuilder

pub fn preserve_n_last(self, n: usize) -> HistoryBuilder

Number of trailing messages the strategy must preserve verbatim (after walking back to a safe User-without-ToolResult boundary). Default: 4. Lowering it lets compaction reclaim more budget at the cost of dropping more recent context; raising it keeps recent turns at the cost of compacting sooner.

pub fn tokenizer(self, tokenizer: Box<dyn Tokenizer>) -> HistoryBuilder

Wire a Tokenizer into the manager. Replaces the default CharTokenizer fallback so History::compact_if_needed measures the budget in real tokens rather than len() / 4.

pub fn strategy(self, strategy: Box<dyn CompactionStrategy>) -> HistoryBuilder

Wire a CompactionStrategy into the manager. Replaces the default TruncateStrategy. Use Box::new(SummarizeStrategy::new(model)) to compress dropped history into a model-generated summary instead of losing it.

pub fn build(self) -> History

Finalize the configuration and build the History. Infallible — every error case is caught by the typed setters.