/*
 * This file is part of the UCB release of Plan 9. It is subject to the license
 * terms in the LICENSE file found in the top-level directory of this
 * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
 * part of the UCB release of Plan 9, including this file, may be copied,
 * modified, propagated, or distributed except according to the terms contained
 * in the LICENSE file.
 */

#include	<u.h>
#include	<lib9.h>
#include	<bio.h>

#ifndef	EXTERN
#define	EXTERN	extern
#endif

typedef struct Re Re;
typedef struct Re2 Re2;
typedef struct State State;

struct State {
	int count;
	int match;
	Re **re;
	State *linkleft;
	State *linkright;
	State *next[256];
};
struct Re2 {
	Re *beg;
	Re *end;
};
struct Re {
	uint8_t type;
	uint16_t gen;
	union {
		Re *alt;				/* Talt */
		Re **cases;				/* case */
		struct {				/* class */
			Rune lo;
			Rune hi;
		};
		Rune val;				/* char */
	};
	Re *next;
};

enum {
	Talt = 1,
	Tbegin,
	Tcase,
	Tclass,
	Tend,
	Tor,

	Caselim = 7,
	Nhunk = 1 << 16,
	Cbegin = Runemax + 1,
	Flshcnt = (1 << 9) - 1,

	Cflag = 1 << 0,
	Hflag = 1 << 1,
	Iflag = 1 << 2,
	Llflag = 1 << 3,
	LLflag = 1 << 4,
	Nflag = 1 << 5,
	Sflag = 1 << 6,
	Vflag = 1 << 7,
	Bflag = 1 << 8
};

EXTERN union {
	char string[16 * 1024];
	struct {
		/*
		 * if a line requires multiple reads, we keep shifting
		 * buf down into pre and then do another read into
		 * buf.  so you'll get the last 16-32k of the matching line.
		 * if pre were smaller than buf you'd get a suffix of the
		 * line with a hole cut out.
		 */
		uint8_t pre[16 * 1024];	/* to save to previous '\n' */
		uint8_t buf[16 * 1024];	/* input buffer */
	};
} u;

EXTERN char *filename;
EXTERN char *pattern;
EXTERN Biobuf bout;
EXTERN char flags[256];
EXTERN Re **follow;
EXTERN uint16_t gen;
EXTERN char *input;
EXTERN int32_t lineno;
EXTERN int literal;
EXTERN int matched;
EXTERN int32_t maxfollow;
EXTERN int32_t nfollow;
EXTERN int peekc;
EXTERN Biobuf *rein;
EXTERN State *state0;
EXTERN Re2 topre;

extern Re *addcase(Re *);
extern void appendnext(Re *, Re *);
extern void error(char *);
extern int fcmp(const void *, const void *);	/* (Re**, Re**) */
extern void fol1(Re *, int);
extern int getrec(void);
extern void increment(State *, int);
extern State *initstate(Re *);
extern void *mal(int);
extern void patchnext(Re *, Re *);
extern Re *ral(int);
extern Re2 re2cat(Re2, Re2);
extern Re2 re2class(char *);
extern Re2 re2or(Re2, Re2);
extern Re2 re2char(int, int);
extern Re2 re2star(Re2);
extern State *sal(int);
extern int search(char *, int);
extern void str2top(char *);
extern int yyparse(void);
extern void reprint(char *, Re *);
extern void yyerror(char *, ...);