/* 
 * $Id: awk.h,v 1.15 2006-01-19 16:28:21 bacon Exp $
 */

#ifndef _XP_AWK_AWK_H_
#define _XP_AWK_AWK_H_

#ifdef __STAND_ALONE
#include <xp/awk/sa.h>
#else
#include <xp/types.h>
#include <xp/macros.h>
#include <xp/bas/str.h>
#endif

#include <xp/awk/tree.h>

enum
{
	XP_AWK_ENOERR,
	XP_AWK_ENOMEM, /* out of memory */
	XP_AWK_ESRCOP,
	XP_AWK_ESRCCL,
	XP_AWK_ESRCDT, /* error in reading source */

	XP_AWK_ELXCHR, /* lexer came accross an wrong character */
	XP_AWK_ELXUNG, /* lexer failed to unget a character */

	XP_AWK_EENDSRC, /* unexpected end of source */
	XP_AWK_ELBRACE, /* left brace expected */
	XP_AWK_ELPAREN, /* left parenthesis expected */
	XP_AWK_ERPAREN, /* right parenthesis expected */
	XP_AWK_ERBRACK, /* right bracket expected */
	XP_AWK_ECOMMA,  /* comma expected */
	XP_AWK_ESEMICOLON, /* semicolon expected */
	XP_AWK_EEXPR,   /* expression expected */

	XP_AWK_EWHILE,  /* keyword 'while' is expected */
	XP_AWK_EASSIGN  /* assignment statement expected */
};

/*
 * TYPE: xp_awk_t
 */
typedef struct xp_awk_t xp_awk_t;

/*
 * TYPE: xp_awk_io_t
 */
typedef xp_ssize_t (*xp_awk_io_t) (
	int cmd, void* arg, xp_char_t* data, xp_size_t count);

/* io function commands */
enum 
{
	XP_AWK_IO_OPEN,
	XP_AWK_IO_CLOSE,
	XP_AWK_IO_DATA
};

/* options */
enum
{
	XP_AWK_ASSIGN_ONLY /* a non-assignment expression cannot be used as a statement */
};

struct xp_awk_t
{
	/* options */
	int opt;

	/* parse tree */
	xp_awk_node_t* tree;

	/* io functions */
	xp_awk_io_t src_func;
	xp_awk_io_t in_func;
	xp_awk_io_t out_func;

	void* src_arg;
	void* in_arg;
	void* out_arg;

	/* source buffer management */
	struct {
		xp_cint_t curc;
		xp_cint_t ungotc[5];
		xp_size_t ungotc_count;
	} lex;

	/* token */
	struct {
		int       type;
		xp_str_t  name;
	} token;

	/* housekeeping */
	int errnum;
	xp_bool_t __dynamic;
};

#ifdef __cplusplus
extern "C" {
#endif

/*
 * FUNCTION: xp_awk_open
 */
xp_awk_t* xp_awk_open (xp_awk_t* awk);

/*
 * FUNCTION: xp_awk_close
 */
int xp_awk_close (xp_awk_t* awk);

/*
 * FUNCTION: xp_awk_attsrc
 */
int xp_awk_attsrc (xp_awk_t* awk, xp_awk_io_t src, void* arg);

/*
 * FUNCTION: xp_awk_detsrc
 */
int xp_awk_detsrc (xp_awk_t* awk);

int xp_awk_attin (xp_awk_t* awk, xp_awk_io_t in, void* arg);
int xp_awk_detin (xp_awk_t* awk);

int xp_awk_attout (xp_awk_t* awk, xp_awk_io_t out, void* arg);
int xp_awk_detout (xp_awk_t* awk);

int xp_awk_parse (xp_awk_t* awk);

#ifdef __cplusplus
}
#endif

#endif