lloyal::grammar Namespace Reference

Functions
std::string	from_json_schema (const std::string &schema_json)
	Convert JSON schema to GBNF (Grammar BNF) format.
llama_sampler *	init_sampler (const llama_model *model, const std::string &grammar_str, const std::string &root_rule="root")
	Initialize a grammar sampler from GBNF grammar string.
llama_sampler *	init_lazy_sampler (const llama_model *model, const std::string &grammar_str, const std::vector< std::string > &trigger_patterns, const std::vector< llama_token > &trigger_tokens, const std::string &root_rule="root")
	Initialize a lazy grammar sampler from GBNF grammar string.
llama_sampler *	clone_sampler (llama_sampler *smpl)
	Clone a grammar sampler (for fork/branching).
void	free_sampler (llama_sampler *smpl)
	Free a grammar sampler.
void	apply (llama_sampler *smpl, llama_token_data_array *cur_p)
	Apply grammar constraint to candidates.
void	accept (llama_sampler *smpl, llama_token token)
	Accept a token into grammar state.

Function Documentation

accept()

void lloyal::grammar::accept ( llama_sampler *  smpl, llama_token  token  )

inline

Accept a token into grammar state.

Advances the grammar parser state.

Parameters

smpl	Grammar sampler
token	Token to accept

Examples

/home/runner/work/liblloyal/liblloyal/include/lloyal/branch.hpp, and /home/runner/work/liblloyal/liblloyal/include/lloyal/grammar.hpp.

Definition at line 262 of file grammar.hpp.

apply()

void lloyal::grammar::apply ( llama_sampler *  smpl, llama_token_data_array *  cur_p  )

inline

Apply grammar constraint to candidates.

Modifies candidates in-place, masking tokens that violate grammar.

Parameters

smpl	Grammar sampler
cur_p	Candidate array (modified in-place)

Examples

/home/runner/work/liblloyal/liblloyal/include/lloyal/branch.hpp, and /home/runner/work/liblloyal/liblloyal/include/lloyal/grammar.hpp.

Definition at line 248 of file grammar.hpp.

clone_sampler()

llama_sampler * lloyal::grammar::clone_sampler ( llama_sampler *  smpl )

inline

Clone a grammar sampler (for fork/branching).

Creates a deep copy of the sampler including its parser state. Use when forking a stepper to preserve grammar position.

Parameters

smpl	Source sampler to clone

Returns

New sampler with same state, or nullptr if input was null

OWNERSHIP: Caller owns returned sampler and must call llama_sampler_free()

Examples

/home/runner/work/liblloyal/liblloyal/include/lloyal/branch.hpp, and /home/runner/work/liblloyal/liblloyal/include/lloyal/grammar.hpp.

Definition at line 212 of file grammar.hpp.

free_sampler()

void lloyal::grammar::free_sampler ( llama_sampler *  smpl )

inline

Free a grammar sampler.

Parameters

smpl	Sampler to free (safe to call with nullptr)

Examples

/home/runner/work/liblloyal/liblloyal/include/lloyal/branch.hpp, and /home/runner/work/liblloyal/liblloyal/include/lloyal/grammar.hpp.

Definition at line 234 of file grammar.hpp.

from_json_schema()

std::string lloyal::grammar::from_json_schema ( const std::string &  schema_json )

inline

Convert JSON schema to GBNF (Grammar BNF) format.

Parameters

schema_json

JSON schema string (e.g., {"type": "object", "properties": {...}})

Returns

GBNF grammar string compatible with llama_sampler_init_grammar()

Exceptions

std::runtime_error

on parse error or conversion failure

EXAMPLE: std::string schema = R"({"type": "object", "properties": {"name": {"type": "string"}}})"; std::string gbnf = grammar::from_json_schema(schema);

Examples

/home/runner/work/liblloyal/liblloyal/include/lloyal/grammar.hpp.

Definition at line 46 of file grammar.hpp.

init_lazy_sampler()

llama_sampler * lloyal::grammar::init_lazy_sampler ( const llama_model *  model, const std::string &  grammar_str, const std::vector< std::string > &  trigger_patterns, const std::vector< llama_token > &  trigger_tokens, const std::string &  root_rule = "root"  )

inline

Initialize a lazy grammar sampler from GBNF grammar string.

Generation runs unconstrained until a trigger pattern or token fires, at which point the grammar activates and constrains subsequent tokens. Used for tool-call generation: model writes freely until <tool_call>, then grammar forces valid XML structure.

Parameters

model	Llama model (for vocab extraction)
grammar_str	GBNF grammar string
trigger_patterns	Regex patterns that activate the grammar
trigger_tokens	Token IDs that activate the grammar
root_rule	Root rule name (default: "root")

Returns

Initialized lazy grammar sampler, or nullptr on failure

OWNERSHIP: Caller owns returned sampler and must call llama_sampler_free()

Examples

/home/runner/work/liblloyal/liblloyal/include/lloyal/branch.hpp, and /home/runner/work/liblloyal/liblloyal/include/lloyal/grammar.hpp.

Definition at line 157 of file grammar.hpp.

init_sampler()

llama_sampler * lloyal::grammar::init_sampler ( const llama_model *  model, const std::string &  grammar_str, const std::string &  root_rule = "root"  )

inline

Initialize a grammar sampler from GBNF grammar string.

Convenience wrapper that handles vocab extraction from model.

Parameters

model	Llama model (for vocab extraction)
grammar_str	GBNF grammar string (from from_json_schema or hand-written)
root_rule	Root rule name (default: "root")

Returns

Initialized grammar sampler, or nullptr on failure

OWNERSHIP: Caller owns returned sampler and must call llama_sampler_free()

EXAMPLE: std::string gbnf = grammar::from_json_schema(schema); llama_sampler* sampler = grammar::init_sampler(model, gbnf); // ... use sampler ... llama_sampler_free(sampler);

Examples

/home/runner/work/liblloyal/liblloyal/include/lloyal/branch.hpp, and /home/runner/work/liblloyal/liblloyal/include/lloyal/grammar.hpp.

Definition at line 106 of file grammar.hpp.