Struct ToolCallExtensions 

pub struct ToolCallExtensions { /* private fields */ }

Per-call runtime extensions supplied to a tool by its caller.

A type-map that allows callers to attach arbitrary typed values and tools to extract them. Tools that don’t need any extensions ignore them.

Inspired by http::Extensions. Backed by the shared internal TypeMap, so empty extensions (the common case when no caller-provided values are needed) require zero allocation.

Tools receive these by shared reference, so a tool reads values with get / require / contains; the mutating accessors (insert, get_mut, remove) are owner-side, used by the caller that builds the extensions before a run.

Values are keyed by TypeId, so get returns None both when nothing was inserted under that type and when a different type was inserted. For tools that genuinely require a value, prefer require, which returns a descriptive error instead of a silent None.

The result-side counterpart — metadata a tool attaches to its output — is ToolResultExtensions.

Example

use rig_core::tool::ToolCallExtensions;

let mut extensions = ToolCallExtensions::new();
assert_eq!(extensions.insert(42u32), None); // no prior value
assert_eq!(extensions.get::<u32>(), Some(&42));
assert_eq!(extensions.insert(7u32), Some(42)); // returns the displaced value

Implementations

impl ToolCallExtensions

pub const fn new() -> Self

Create an empty set of extensions.

pub fn insert<T: Clone + WasmCompatSend + WasmCompatSync + 'static>( &mut self, val: T, ) -> Option<T>

Insert a typed value, returning the previous value of the same type if one was present (mirroring http::Extensions::insert and HashMap::insert).

pub fn get<T: WasmCompatSend + WasmCompatSync + 'static>(&self) -> Option<&T>

Get a reference to a value by type. Returns None if not present.

pub fn require<T: WasmCompatSend + WasmCompatSync + 'static>( &self, ) -> Result<&T, MissingExtension>

Get a reference to a value by type, returning a descriptive error instead of None when it is absent.

Prefer this over get for tools that require an extension value (auth tokens, session IDs, …): the error names the missing type, turning a silent None into an actionable failure.

pub fn get_mut<T: WasmCompatSend + WasmCompatSync + 'static>( &mut self, ) -> Option<&mut T>

Get a mutable reference to a value by type. Returns None if not present.

pub fn remove<T: WasmCompatSend + WasmCompatSync + 'static>( &mut self, ) -> Option<T>

Remove a value by type, returning it if present.

pub fn contains<T: WasmCompatSend + WasmCompatSync + 'static>(&self) -> bool

Check if a value of the given type is present.

pub fn len(&self) -> usize

Number of values currently stored.

pub fn is_empty(&self) -> bool

Whether no values are stored.

Trait Implementations

impl Clone for ToolCallExtensions

fn clone(&self) -> ToolCallExtensions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ToolCallExtensions

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

Formats the value using the given formatter.

impl Default for ToolCallExtensions

fn default() -> ToolCallExtensions

Returns the “default value” for a type.