rdesc.h File Reference

The Right-Recursive Descent Parser. More...

#include <stdint.h>

Go to the source code of this file.

Classes
struct	rdesc
	Right-recursive descent parser. More...
struct	rdesc_token
	terminal (token) object for context-free grammar More...
struct	rdesc_nonterminal
	nonterminal (syntatic variable) object for context-free grammar More...
struct	rdesc_node
	A node in the CST. More...

Macros
#define	RDESC_VERSION_MAJOR   0
	major version
#define	RDESC_VERSION_MINOR   1
	minor version
#define	RDESC_VERSION_PATCH   0
	patch version
#define	RDESC_VERSION_PRE_RELEASE   ""
	prerelase identifier

Typedefs
typedef void(*	rdesc_tk_destroyer_func) (struct rdesc_token *)
	Function pointer type for freeing tokens.

Enumerations
enum	rdesc_result { RDESC_READY , RDESC_CONTINUE , RDESC_NOMATCH }
	parsing status More...

Functions
void	rdesc_init (struct rdesc *p, const struct rdesc_cfg *cfg)
	Initializes a new parser.
void	rdesc_destroy (struct rdesc *p)
	Frees memory allocated by the parser and destroys the parser instance.
void	rdesc_start (struct rdesc *p, int start_symbol)
	Sets start symbol for the next match.
void	rdesc_reset (struct rdesc *p, rdesc_tk_destroyer_func free_tk)
	Resets parser and its state.
enum rdesc_result	rdesc_pump (struct rdesc *p, struct rdesc_node **out, struct rdesc_token *incoming_tk)
	Drives the parsing process, The Pump.
void	rdesc_node_destroy (struct rdesc_node *n, rdesc_tk_destroyer_func free_tk)
	Recursively destroys the node and its children.

Detailed Description

The Right-Recursive Descent Parser.

Enumeration Type Documentation

rdesc_result

enum rdesc_result

parsing status

Enumerator
RDESC_READY	a tree is ready for consumption
RDESC_CONTINUE	new tokens should be provided
RDESC_NOMATCH	provided tokens do not match with any rule

Function Documentation

rdesc_destroy()

void rdesc_destroy

(

struct rdesc *

p

)

Frees memory allocated by the parser and destroys the parser instance.

Warning

The token stack must be empty and no parse in progress before calling this function to prevent memory leaks. Raises an assertion error if the token stack is not empty or the root is not null.

rdesc_node_destroy()

void rdesc_node_destroy	(	struct rdesc_node *	n,
		rdesc_tk_destroyer_func	free_tk
	)

Recursively destroys the node and its children.

Note

seminfo field in struct rdesc_token are not freed unless free_tk is set.

rdesc_pump()

enum rdesc_result rdesc_pump	(	struct rdesc *	p,
		struct rdesc_node **	out,
		struct rdesc_token *	incoming_tk
	)

Drives the parsing process, The Pump.

As the central engine of the parser, it consumes tokens from either the internal backtracking stack or the provided incoming_tk.

Parameters

p	Pointer to the parser instance.
out	Output pointer for the resulting CST node (if READY).
incoming_tk	Pointer to the next token to consume. Optional: Pass NULL to resume parsing using only the tokens currently in the backtracking stack. Storage: The pointer is used solely to make the argument nullable (optional). It does not imply that the token must be heap-allocated. Passing a pointer to a stack-allocated (automatic) variable is valid and expected, as the parser copies the token data internally.

Returns

The current status of the parse operation.

rdesc_reset()

void rdesc_reset	(	struct rdesc *	p,
		rdesc_tk_destroyer_func	free_tk
	)

Resets parser and its state.

Note

seminfo field in struct rdesc_token are not freed unless free_tk is set.