Enum GrammarStart 

pub enum GrammarStart {
    Unknown,
    AfterReasoning,
    FirstToken,
}

Where the engine that runs a forced call’s grammar starts applying it on a prompt that ends inside the model’s thinking block, as its worker advertises it (the constrained_decoding_start label).

An engine’s own server picks the grammar’s shape from this: it sends xgrammar’s reasoning-aware tags (the thought, its close, then the calls) when it runs no reasoning parser and the bare calls when it does, because its grammar backend then waits for the thought’s end; an engine with a reasoning parser set (and enable_in_reasoning off) waits the same way. The gateway reads the same fact from the worker and shapes the calls’ prefix accordingly.

Variants

Unknown

The worker does not say (an older servicer, an engine without the label): free text with nothing owed at its end precedes the calls, which fits an engine of either kind.

AfterReasoning

The engine applies the grammar only once its reasoning parser has seen the model’s own </think>: nothing precedes the calls, so the call is forced right at that gate, as the engine’s own server does.

FirstToken

The engine applies the grammar from the first generated token: the thought, its close and then the calls, so the call is not forced into the thought.

Implementations

impl GrammarStart

pub const LABEL: &'static str = "constrained_decoding_start"

The worker label that carries it.

pub const AFTER_REASONING: &'static str = "after_reasoning"

The label’s value for Self::AfterReasoning.

pub const FIRST_TOKEN: &'static str = "first_token"

The label’s value for Self::FirstToken.

pub fn from_label(value: Option<&str>) -> Self

The start a worker’s constrained_decoding_start label names; anything else, the label’s absence included, is Self::Unknown.

Trait Implementations

impl Clone for GrammarStart

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for GrammarStart

impl Debug for GrammarStart

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

Formats the value using the given formatter.

impl Default for GrammarStart

fn default() -> Self

Returns the “default value” for a type.

impl Eq for GrammarStart

impl PartialEq for GrammarStart

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for GrammarStart