Grammar Context API

Create, manage, and query the grammar context stack. More...

Functions
bool	grammar_context_close_bracket (GrammarContextStack *stack)
	Notify the context stack that a bracket/parenthesis was closed.
GrammarContextStack *	grammar_context_create (ParserSnapshot *root_snapshot)
	Create a context stack with the given root grammar snapshot.
GrammarMode	grammar_context_current_mode (const GrammarContextStack *stack)
	Return the current grammar mode.
ParserSnapshot *	grammar_context_current_snapshot (const GrammarContextStack *stack)
	Return the snapshot for the current (topmost) grammar context.
uint32_t	grammar_context_depth (const GrammarContextStack *stack)
	Return the current nesting depth (0 = root).
void	grammar_context_destroy (GrammarContextStack *stack)
	Destroy the context stack and release all snapshot references.
bool	grammar_context_detect_exit (GrammarContextStack *stack, int token_code)
	Detect whether the current embedded context should end.
bool	grammar_context_detect_switch (GrammarContextStack *stack, int token_code, const char *lexeme, uint32_t offset)
	Detect whether a context switch should occur.
bool	grammar_context_is_root_only (const GrammarContextStack *stack)
	Check if only the root grammar is active.
void	grammar_context_open_bracket (GrammarContextStack *stack)
	Notify the context stack that a bracket/parenthesis was opened.
bool	grammar_context_pop (GrammarContextStack *stack)
	Pop the current grammar context.
bool	grammar_context_push (GrammarContextStack *stack, GrammarMode mode, uint32_t offset)
	Explicitly push a grammar mode onto the context stack.
bool	grammar_context_register_mode (GrammarContextStack *stack, const GrammarModeInfo *info)
	Register a grammar mode.
void	grammar_context_set_switch_callback (GrammarContextStack *stack, ContextSwitchCallback cb, void *user_data)
	Register a callback to be invoked on context switches.

Detailed Description

Create, manage, and query the grammar context stack.

Function Documentation

grammar_context_close_bracket()

bool grammar_context_close_bracket

(

GrammarContextStack *

stack

)

#include <include/grammar_context.h>

Notify the context stack that a bracket/parenthesis was closed.

May trigger an automatic context pop if the mode's depth returns to its entry depth.

Parameters

stack

The context stack.

Return values

true	A context pop was triggered by bracket close.
false	No pop occurred.

grammar_context_create()

GrammarContextStack * grammar_context_create

(

ParserSnapshot *

root_snapshot

)

#include <include/grammar_context.h>

Create a context stack with the given root grammar snapshot.

The root mode is MODE_SQL. Acquires a reference to root_snapshot.

Parameters

root_snapshot

Snapshot for the root (SQL) grammar.

Returns

New context stack, or NULL on allocation failure.

See also

grammar_context_destroy()

grammar_context_current_mode()

GrammarMode grammar_context_current_mode

(

const GrammarContextStack *

stack

)

#include <include/grammar_context.h>

Return the current grammar mode.

Parameters

stack

The context stack.

Returns

Current GrammarMode value.

grammar_context_current_snapshot()

ParserSnapshot * grammar_context_current_snapshot

(

const GrammarContextStack *

stack

)

#include <include/grammar_context.h>

Return the snapshot for the current (topmost) grammar context.

Parameters

stack

The context stack.

Returns

Current snapshot. Valid until the next push/pop.

grammar_context_depth()

uint32_t grammar_context_depth

(

const GrammarContextStack *

stack

)

#include <include/grammar_context.h>

Return the current nesting depth (0 = root).

Parameters

stack

The context stack.

Returns

Nesting depth.

grammar_context_destroy()

void grammar_context_destroy

(

GrammarContextStack *

stack

)

#include <include/grammar_context.h>

Destroy the context stack and release all snapshot references.

Parameters

stack

Stack to destroy. Passing NULL is safe.

grammar_context_detect_exit()

bool grammar_context_detect_exit	(	GrammarContextStack *	stack,
		int	token_code
	)

#include <include/grammar_context.h>

Detect whether the current embedded context should end.

If so, the context is popped and the function returns true. The caller should switch back to grammar_context_current_snapshot().

Parameters

stack	The context stack.
token_code	The token code just lexed.

Return values

true	Context was popped; previous mode is now active.
false	No exit detected; continue in the current mode.

grammar_context_detect_switch()

bool grammar_context_detect_switch	(	GrammarContextStack *	stack,
		int	token_code,
		const char *	lexeme,
		uint32_t	offset
	)

#include <include/grammar_context.h>

Detect whether a context switch should occur.

If a switch is detected, the appropriate context is pushed and the function returns true. The caller should then use grammar_context_current_snapshot() for subsequent parsing.

Parameters

stack	The context stack.
token_code	The token code just lexed.
lexeme	The lexeme text (may be NULL).
offset	Current offset in the input stream.

Return values

true	A context switch occurred; new mode is active.
false	No switch; continue with the current mode.

grammar_context_is_root_only()

bool grammar_context_is_root_only

(

const GrammarContextStack *

stack

)

#include <include/grammar_context.h>

Check if only the root grammar is active.

This is the fast-path check: if true, the parser can skip all mode-detection logic.

Parameters

stack

The context stack.

Return values

true	Only the root grammar is active (no embedded contexts).
false	One or more embedded contexts are active.

grammar_context_open_bracket()

void grammar_context_open_bracket

(

GrammarContextStack *

stack

)

#include <include/grammar_context.h>

Notify the context stack that a bracket/parenthesis was opened.

Used for depth tracking in modes that exit when their enclosing brackets close.

Parameters

stack

The context stack.

grammar_context_pop()

bool grammar_context_pop

(

GrammarContextStack *

stack

)

#include <include/grammar_context.h>

Pop the current grammar context.

Parameters

stack

The context stack.

Return values

true	A context was popped.
false	Already at the root (nothing to pop).

grammar_context_push()

bool grammar_context_push	(	GrammarContextStack *	stack,
		GrammarMode	mode,
		uint32_t	offset
	)

#include <include/grammar_context.h>

Explicitly push a grammar mode onto the context stack.

Parameters

stack	The context stack.
mode	Grammar mode to push.
offset	Current input offset.

Return values

true	Push succeeded.
false	Mode not registered or allocation failed.

grammar_context_register_mode()

bool grammar_context_register_mode	(	GrammarContextStack *	stack,
		const GrammarModeInfo *	info
	)

#include <include/grammar_context.h>

Register a grammar mode.

The stack acquires a reference to the mode's snapshot.

Parameters

stack	Stack to register the mode with.
info	Mode descriptor.

Return values

true	Registration succeeded.
false	Mode already registered or allocation failed.

grammar_context_set_switch_callback()

void grammar_context_set_switch_callback	(	GrammarContextStack *	stack,
		ContextSwitchCallback	cb,
		void *	user_data
	)

#include <include/grammar_context.h>

Register a callback to be invoked on context switches.

Parameters

stack	The context stack.
cb	Callback function (may be NULL to unregister).
user_data	Opaque pointer forwarded to cb.