/* deflate.c -- compress data using the deflation algorithm
 * Copyright (C) 1995-2022 Jean-loup Gailly and Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

/*
 *  ALGORITHM
 *
 *      The "deflation" process depends on being able to identify portions

 */

/* @(#) $Id$ */

#include "deflate.h"

const char deflate_copyright[] =
   " deflate 1.2.13 Copyright 1995-2022 Jean-loup Gailly and Mark Adler ";
/*
  If you use the zlib library in a product, an acknowledgment is welcome
  in the documentation of your product. If for some reason you cannot
  include such an acknowledgment, I would appreciate that you keep this
  copyright string in the executable of your product.
 */

/* ===========================================================================
 *  Function prototypes.
 */
typedef enum {
    need_more,      /* block not completed, need more input or more output */
    block_done,     /* block flush performed */
    finish_started, /* finish started, need only more output at next deflate */
    finish_done     /* finish done, accept no more input or output */
} block_state;

typedef block_state (*compress_func) OF((deflate_state *s, int flush));
/* Compression function. Returns the block state after the call. */

local int deflateStateCheck      OF((z_streamp strm));
local void slide_hash     OF((deflate_state *s));
local void fill_window    OF((deflate_state *s));
local block_state deflate_stored OF((deflate_state *s, int flush));
local block_state deflate_fast   OF((deflate_state *s, int flush));
#ifndef FASTEST
local block_state deflate_slow   OF((deflate_state *s, int flush));
#endif
local block_state deflate_rle    OF((deflate_state *s, int flush));
local block_state deflate_huff   OF((deflate_state *s, int flush));
local void lm_init        OF((deflate_state *s));
local void putShortMSB    OF((deflate_state *s, uInt b));
local void flush_pending  OF((z_streamp strm));
local unsigned read_buf   OF((z_streamp strm, Bytef *buf, unsigned size));
local uInt longest_match  OF((deflate_state *s, IPos cur_match));

#ifdef ZLIB_DEBUG
local  void check_match OF((deflate_state *s, IPos start, IPos match,
                            int length));
#endif

/* ===========================================================================
 * Local data
 */

#define NIL 0
/* Tail of hash chains */

    } while (0)

/* ===========================================================================
 * Slide the hash table when sliding the window down (could be avoided with 32
 * bit values at the expense of memory usage). We slide even when level == 0 to
 * keep the hash table consistent if we switch back to level > 0 later.
 */





local void slide_hash(s)
    deflate_state *s;
{
    unsigned n, m;
    Posf *p;
    uInt wsize = s->w_size;

    n = s->hash_size;
    p = &s->head[n];
    do {

        *p = (Pos)(m >= wsize ? m - wsize : NIL);
        /* If n is not on any hash chain, prev[n] is garbage but
         * its value will never be used.
         */
    } while (--n);
#endif
}
































































































































































/* ========================================================================= */
int ZEXPORT deflateInit_(strm, level, version, stream_size)
    z_streamp strm;
    int level;
    const char *version;
    int stream_size;
{
    return deflateInit2_(strm, level, Z_DEFLATED, MAX_WBITS, DEF_MEM_LEVEL,
                         Z_DEFAULT_STRATEGY, version, stream_size);
    /* To do: ignore strm->next_in if we use it as window */
}

/* ========================================================================= */
int ZEXPORT deflateInit2_(strm, level, method, windowBits, memLevel, strategy,
                  version, stream_size)
    z_streamp strm;
    int  level;
    int  method;
    int  windowBits;
    int  memLevel;
    int  strategy;
    const char *version;
    int stream_size;
{
    deflate_state *s;
    int wrap = 1;
    static const char my_version[] = ZLIB_VERSION;

    if (version == Z_NULL || version[0] != my_version[0] ||
        stream_size != sizeof(z_stream)) {
        return Z_VERSION_ERROR;

    return deflateReset(strm);
}

/* =========================================================================
 * Check for a valid deflate stream state. Return 0 if ok, 1 if not.
 */
local int deflateStateCheck(strm)
    z_streamp strm;
{
    deflate_state *s;
    if (strm == Z_NULL ||
        strm->zalloc == (alloc_func)0 || strm->zfree == (free_func)0)
        return 1;
    s = strm->state;
    if (s == Z_NULL || s->strm != strm || (s->status != INIT_STATE &&
#ifdef GZIP
                                           s->status != GZIP_STATE &&
#endif
                                           s->status != EXTRA_STATE &&
                                           s->status != NAME_STATE &&
                                           s->status != COMMENT_STATE &&
                                           s->status != HCRC_STATE &&
                                           s->status != BUSY_STATE &&
                                           s->status != FINISH_STATE))
        return 1;
    return 0;
}

/* ========================================================================= */
int ZEXPORT deflateSetDictionary(strm, dictionary, dictLength)
    z_streamp strm;
    const Bytef *dictionary;
    uInt  dictLength;
{
    deflate_state *s;
    uInt str, n;
    int wrap;
    unsigned avail;
    z_const unsigned char *next;

    if (deflateStateCheck(strm) || dictionary == Z_NULL)

    strm->next_in = next;
    strm->avail_in = avail;
    s->wrap = wrap;
    return Z_OK;
}

/* ========================================================================= */
int ZEXPORT deflateGetDictionary(strm, dictionary, dictLength)
    z_streamp strm;
    Bytef *dictionary;
    uInt  *dictLength;
{
    deflate_state *s;
    uInt len;

    if (deflateStateCheck(strm))
        return Z_STREAM_ERROR;
    s = strm->state;
    len = s->strstart + s->lookahead;
    if (len > s->w_size)
        len = s->w_size;
    if (dictionary != Z_NULL && len)
        zmemcpy(dictionary, s->window + s->strstart + s->lookahead - len, len);
    if (dictLength != Z_NULL)
        *dictLength = len;
    return Z_OK;
}

/* ========================================================================= */
int ZEXPORT deflateResetKeep(strm)
    z_streamp strm;
{
    deflate_state *s;

    if (deflateStateCheck(strm)) {
        return Z_STREAM_ERROR;
    }

    strm->total_in = strm->total_out = 0;

        adler32(0L, Z_NULL, 0);
    s->last_flush = -2;

    _tr_init(s);

    return Z_OK;
}

/* ========================================================================= */




int ZEXPORT deflateReset(strm)

    z_streamp strm;






{











    int ret;

    ret = deflateResetKeep(strm);
    if (ret == Z_OK)
        lm_init(strm->state);
    return ret;
}

/* ========================================================================= */
int ZEXPORT deflateSetHeader(strm, head)
    z_streamp strm;
    gz_headerp head;
{
    if (deflateStateCheck(strm) || strm->state->wrap != 2)
        return Z_STREAM_ERROR;
    strm->state->gzhead = head;
    return Z_OK;
}

/* ========================================================================= */
int ZEXPORT deflatePending(strm, pending, bits)
    unsigned *pending;
    int *bits;
    z_streamp strm;
{
    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
    if (pending != Z_NULL)
        *pending = strm->state->pending;
    if (bits != Z_NULL)
        *bits = strm->state->bi_valid;
    return Z_OK;
}

/* ========================================================================= */
int ZEXPORT deflatePrime(strm, bits, value)
    z_streamp strm;
    int bits;
    int value;
{
    deflate_state *s;
    int put;

    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
    s = strm->state;
    if (bits < 0 || bits > 16 ||
        s->sym_buf < s->pending_out + ((Buf_size + 7) >> 3))

        value >>= put;
        bits -= put;
    } while (bits);
    return Z_OK;
}

/* ========================================================================= */
int ZEXPORT deflateParams(strm, level, strategy)
    z_streamp strm;
    int level;
    int strategy;
{
    deflate_state *s;
    compress_func func;

    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
    s = strm->state;

#ifdef FASTEST

        s->max_chain_length = configuration_table[level].max_chain;
    }
    s->strategy = strategy;
    return Z_OK;
}

/* ========================================================================= */
int ZEXPORT deflateTune(strm, good_length, max_lazy, nice_length, max_chain)
    z_streamp strm;
    int good_length;
    int max_lazy;
    int nice_length;
    int max_chain;
{
    deflate_state *s;

    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;
    s = strm->state;
    s->good_match = (uInt)good_length;
    s->max_lazy_match = (uInt)max_lazy;
    s->nice_match = nice_length;

 * a stored block from being emitted. Then the only choice is a fixed or
 * dynamic block, where a fixed block limits the maximum expansion to 9 bits
 * per 8-bit byte, plus 10 bits for every block. The smallest block size for
 * which this can occur is 255 (memLevel == 2).
 *
 * Shifts are used to approximate divisions, for speed.
 */
uLong ZEXPORT deflateBound(strm, sourceLen)
    z_streamp strm;
    uLong sourceLen;
{
    deflate_state *s;
    uLong fixedlen, storelen, wraplen;

    /* upper bound for fixed blocks with 9-bit literals and length 255
       (memLevel == 2, which is the lowest that may not use stored blocks) --
       ~13% overhead plus a small constant */
    fixedlen = sourceLen + (sourceLen >> 3) + (sourceLen >> 8) +

#endif
    default:                                /* for compiler happiness */
        wraplen = 6;
    }

    /* if not default parameters, return one of the conservative bounds */
    if (s->w_bits != 15 || s->hash_bits != 8 + 7)
        return (s->w_bits <= s->hash_bits ? fixedlen : storelen) + wraplen;


    /* default settings: return tight bound for that case -- ~0.03% overhead
       plus a small constant */
    return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) +
           (sourceLen >> 25) + 13 - 6 + wraplen;
}

/* =========================================================================
 * Put a short in the pending buffer. The 16-bit value is put in MSB order.
 * IN assertion: the stream state is correct and there is enough room in
 * pending_buf.
 */
local void putShortMSB(s, b)
    deflate_state *s;
    uInt b;
{
    put_byte(s, (Byte)(b >> 8));
    put_byte(s, (Byte)(b & 0xff));
}

/* =========================================================================
 * Flush as much pending output as possible. All deflate() output, except for
 * some deflate_stored() output, goes through this function so some
 * applications may wish to modify it to avoid allocating a large
 * strm->next_out buffer and copying into it. (See also read_buf()).
 */
local void flush_pending(strm)
    z_streamp strm;
{
    unsigned len;
    deflate_state *s = strm->state;

    _tr_flush_bits(s);
    len = s->pending;
    if (len > strm->avail_out) len = strm->avail_out;
    if (len == 0) return;

    do { \
        if (s->gzhead->hcrc && s->pending > (beg)) \
            strm->adler = crc32(strm->adler, s->pending_buf + (beg), \
                                s->pending - (beg)); \
    } while (0)

/* ========================================================================= */
int ZEXPORT deflate(strm, flush)
    z_streamp strm;
    int flush;
{
    int old_flush; /* value of flush param for previous deflate call */
    deflate_state *s;

    if (deflateStateCheck(strm) || flush > Z_BLOCK || flush < 0) {
        return Z_STREAM_ERROR;
    }
    s = strm->state;

     * to flush the rest.
     */
    if (s->wrap > 0) s->wrap = -s->wrap; /* write the trailer only once! */
    return s->pending != 0 ? Z_OK : Z_STREAM_END;
}

/* ========================================================================= */
int ZEXPORT deflateEnd(strm)
    z_streamp strm;
{
    int status;

    if (deflateStateCheck(strm)) return Z_STREAM_ERROR;

    status = strm->state->status;

    /* Deallocate in reverse order of allocations: */

}

/* =========================================================================
 * Copy the source state to the destination state.
 * To simplify the source, this is not supported for 16-bit MSDOS (which
 * doesn't have enough memory anyway to duplicate compression states).
 */
int ZEXPORT deflateCopy(dest, source)
    z_streamp dest;
    z_streamp source;
{
#ifdef MAXSEG_64K


    return Z_STREAM_ERROR;
#else
    deflate_state *ds;
    deflate_state *ss;


    if (deflateStateCheck(source) || dest == Z_NULL) {

    ds->d_desc.dyn_tree = ds->dyn_dtree;
    ds->bl_desc.dyn_tree = ds->bl_tree;

    return Z_OK;
#endif /* MAXSEG_64K */
}

/* ===========================================================================
 * Read a new buffer from the current input stream, update the adler32
 * and total number of bytes read.  All deflate() input goes through
 * this function so some applications may wish to modify it to avoid
 * allocating a large strm->next_in buffer and copying from it.
 * (See also flush_pending()).
 */
local unsigned read_buf(strm, buf, size)
    z_streamp strm;
    Bytef *buf;
    unsigned size;
{
    unsigned len = strm->avail_in;

    if (len > size) len = size;
    if (len == 0) return 0;

    strm->avail_in  -= len;

    zmemcpy(buf, strm->next_in, len);
    if (strm->state->wrap == 1) {
        strm->adler = adler32(strm->adler, buf, len);
    }
#ifdef GZIP
    else if (strm->state->wrap == 2) {
        strm->adler = crc32(strm->adler, buf, len);
    }
#endif
    strm->next_in  += len;
    strm->total_in += len;

    return len;
}

/* ===========================================================================
 * Initialize the "longest match" routines for a new zlib stream
 */
local void lm_init(s)
    deflate_state *s;
{
    s->window_size = (ulg)2L*s->w_size;

    CLEAR_HASH(s);

    /* Set the default configuration parameters:
     */
    s->max_lazy_match   = configuration_table[s->level].max_lazy;
    s->good_match       = configuration_table[s->level].good_length;
    s->nice_match       = configuration_table[s->level].nice_length;
    s->max_chain_length = configuration_table[s->level].max_chain;

    s->strstart = 0;
    s->block_start = 0L;
    s->lookahead = 0;
    s->insert = 0;
    s->match_length = s->prev_length = MIN_MATCH-1;
    s->match_available = 0;
    s->ins_h = 0;
}

#ifndef FASTEST
/* ===========================================================================
 * Set match_start to the longest match starting at the given string and
 * return its length. Matches shorter or equal to prev_length are discarded,
 * in which case the result is equal to prev_length and match_start is
 * garbage.
 * IN assertions: cur_match is the head of the hash chain for the current
 *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
 * OUT assertion: the match length is not greater than s->lookahead.
 */
local uInt longest_match(s, cur_match)
    deflate_state *s;
    IPos cur_match;                             /* current match */
{
    unsigned chain_length = s->max_chain_length;/* max hash chain length */
    register Bytef *scan = s->window + s->strstart; /* current string */
    register Bytef *match;                      /* matched string */
    register int len;                           /* length of current match */
    int best_len = (int)s->prev_length;         /* best match length so far */
    int nice_match = s->nice_match;             /* stop if match long enough */
    IPos limit = s->strstart > (IPos)MAX_DIST(s) ?

}

#else /* FASTEST */

/* ---------------------------------------------------------------------------
 * Optimized version for FASTEST only
 */
local uInt longest_match(s, cur_match)
    deflate_state *s;
    IPos cur_match;                             /* current match */
{
    register Bytef *scan = s->window + s->strstart; /* current string */
    register Bytef *match;                       /* matched string */
    register int len;                           /* length of current match */
    register Bytef *strend = s->window + s->strstart + MAX_MATCH;

    /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
     * It is easy to get rid of this optimization if necessary.

#define EQUAL 0
/* result of memcmp for equal strings */

/* ===========================================================================
 * Check that the match at match_start is indeed a match.
 */
local void check_match(s, start, match, length)
    deflate_state *s;
    IPos start, match;
    int length;
{
    /* check that the match is indeed a match */
    if (zmemcmp(s->window + match,
                s->window + start, length) != EQUAL) {
        fprintf(stderr, " start %u, match %u, length %d\n",
                start, match, length);
        do {
            fprintf(stderr, "%c%c", s->window[match++], s->window[start++]);
        } while (--length != 0);
        z_error("invalid match");
    }
    if (z_verbose > 1) {
        fprintf(stderr,"\\[%d,%d]", start - match, length);
        do { putc(s->window[start++], stderr); } while (--length != 0);
    }
}
#else
#  define check_match(s, start, match, length)
#endif /* ZLIB_DEBUG */

/* ===========================================================================
 * Fill the window when the lookahead becomes insufficient.
 * Updates strstart and lookahead.
 *
 * IN assertion: lookahead < MIN_LOOKAHEAD
 * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD
 *    At least one byte has been read, or avail_in == 0; reads are
 *    performed for at least two bytes (required for the zip translate_eol
 *    option -- not supported here).
 */
local void fill_window(s)
    deflate_state *s;
{
    unsigned n;
    unsigned more;    /* Amount of free space at the end of the window. */
    uInt wsize = s->w_size;

    Assert(s->lookahead < MIN_LOOKAHEAD, "already enough lookahead");

    do {
        more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart);

        /* Deal with !@#$% 64K limit: */
        if (sizeof(int) <= 2) {
            if (more == 0 && s->strstart == 0 && s->lookahead == 0) {
                more = wsize;

            } else if (more == (unsigned)(-1)) {
                /* Very unlikely, but possible on 16 bit machine if
                 * strstart == 0 && lookahead == 1 (input done a byte at time)
                 */
                more--;
            }
        }

        /* If the window is almost full and there is insufficient lookahead,
         * move the upper half to the lower one to make room in the upper half.
         */
        if (s->strstart >= wsize + MAX_DIST(s)) {

            zmemcpy(s->window, s->window + wsize, (unsigned)wsize - more);
            s->match_start -= wsize;
            s->strstart    -= wsize; /* we now have strstart >= MAX_DIST */
            s->block_start -= (long) wsize;
            if (s->insert > s->strstart)
                s->insert = s->strstart;
            slide_hash(s);
            more += wsize;
        }
        if (s->strm->avail_in == 0) break;

        /* If there was no sliding:
         *    strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 &&
         *    more == window_size - lookahead - strstart
         * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1)
         * => more >= window_size - 2*WSIZE + 2
         * In the BIG_MEM or MMAP case (not yet supported),
         *   window_size == input_size + MIN_LOOKAHEAD  &&
         *   strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD.
         * Otherwise, window_size == 2*WSIZE so more >= 2.
         * If there was sliding, more >= WSIZE. So in all cases, more >= 2.
         */
        Assert(more >= 2, "more < 2");

        n = read_buf(s->strm, s->window + s->strstart + s->lookahead, more);
        s->lookahead += n;

        /* Initialize the hash value now that we have some input: */
        if (s->lookahead + s->insert >= MIN_MATCH) {
            uInt str = s->strstart - s->insert;
            s->ins_h = s->window[str];
            UPDATE_HASH(s, s->ins_h, s->window[str + 1]);
#if MIN_MATCH != 3
            Call UPDATE_HASH() MIN_MATCH-3 more times
#endif
            while (s->insert) {
                UPDATE_HASH(s, s->ins_h, s->window[str + MIN_MATCH-1]);
#ifndef FASTEST
                s->prev[str & s->w_mask] = s->head[s->ins_h];
#endif
                s->head[s->ins_h] = (Pos)str;
                str++;
                s->insert--;
                if (s->lookahead + s->insert < MIN_MATCH)
                    break;
            }
        }
        /* If the whole input has less than MIN_MATCH bytes, ins_h is garbage,
         * but this is not important since only literal bytes will be emitted.
         */

    } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);

    /* If the WIN_INIT bytes after the end of the current data have never been
     * written, then zero those bytes in order to avoid memory check reports of
     * the use of uninitialized (or uninitialised as Julian writes) bytes by
     * the longest match routines.  Update the high water mark for the next
     * time through here.  WIN_INIT is set to MAX_MATCH since the longest match
     * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
     */
    if (s->high_water < s->window_size) {
        ulg curr = s->strstart + (ulg)(s->lookahead);
        ulg init;

        if (s->high_water < curr) {
            /* Previous high water mark below current data -- zero WIN_INIT
             * bytes or up to end of window, whichever is less.
             */
            init = s->window_size - curr;
            if (init > WIN_INIT)
                init = WIN_INIT;
            zmemzero(s->window + curr, (unsigned)init);
            s->high_water = curr + init;
        }
        else if (s->high_water < (ulg)curr + WIN_INIT) {
            /* High water mark at or above current data, but below current data
             * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
             * to end of window, whichever is less.
             */
            init = (ulg)curr + WIN_INIT - s->high_water;
            if (init > s->window_size - s->high_water)
                init = s->window_size - s->high_water;
            zmemzero(s->window + s->high_water, (unsigned)init);
            s->high_water += init;
        }
    }

    Assert((ulg)s->strstart <= s->window_size - MIN_LOOKAHEAD,
           "not enough room for search");
}

/* ===========================================================================
 * Flush the current block, with given end-of-file flag.
 * IN assertion: strstart is set to the end of the current match.
 */
#define FLUSH_BLOCK_ONLY(s, last) { \
   _tr_flush_block(s, (s->block_start >= 0L ? \
                   (charf *)&s->window[(unsigned)s->block_start] : \

 * allowed here, then the hash table will be cleared, since two or more slides
 * is the same as a clear.
 *
 * deflate_stored() is written to minimize the number of times an input byte is
 * copied. It is most efficient with large input and output buffers, which
 * maximizes the opportunities to have a single copy from next_in to next_out.
 */
local block_state deflate_stored(s, flush)
    deflate_state *s;
    int flush;
{
    /* Smallest worthy block size when not flushing or finishing. By default
     * this is 32K. This can be as small as 507 bytes for memLevel == 1. For
     * large input and output buffers, the stored block size will be larger.
     */
    unsigned min_block = MIN(s->pending_buf_size - 5, s->w_size);

    /* Copy as many min_block or larger stored blocks directly to next_out as

/* ===========================================================================
 * Compress as much as possible from the input stream, return the current
 * block state.
 * This function does not perform lazy evaluation of matches and inserts
 * new strings in the dictionary only for unmatched strings or for short
 * matches. It is used only for the fast compression options.
 */
local block_state deflate_fast(s, flush)
    deflate_state *s;
    int flush;
{
    IPos hash_head;       /* head of the hash chain */
    int bflush;           /* set if current block must be flushed */

    for (;;) {
        /* Make sure that we always have enough lookahead, except
         * at the end of the input file. We need MAX_MATCH bytes
         * for the next match, plus MIN_MATCH bytes to insert the

#ifndef FASTEST
/* ===========================================================================
 * Same as above, but achieves better compression. We use a lazy
 * evaluation for matches: a match is finally adopted only if there is
 * no better match at the next window position.
 */
local block_state deflate_slow(s, flush)
    deflate_state *s;
    int flush;
{
    IPos hash_head;          /* head of hash chain */
    int bflush;              /* set if current block must be flushed */

    /* Process the input block. */
    for (;;) {
        /* Make sure that we always have enough lookahead, except
         * at the end of the input file. We need MAX_MATCH bytes

#endif /* FASTEST */

/* ===========================================================================
 * For Z_RLE, simply look for runs of bytes, generate matches only of distance
 * one.  Do not maintain a hash table.  (It will be regenerated if this run of
 * deflate switches away from Z_RLE.)
 */
local block_state deflate_rle(s, flush)
    deflate_state *s;
    int flush;
{
    int bflush;             /* set if current block must be flushed */
    uInt prev;              /* byte at distance one to match */
    Bytef *scan, *strend;   /* scan goes up to strend for length of run */

    for (;;) {
        /* Make sure that we always have enough lookahead, except
         * at the end of the input file. We need MAX_MATCH bytes

    return block_done;
}

/* ===========================================================================
 * For Z_HUFFMAN_ONLY, do not look for matches.  Do not maintain a hash table.
 * (It will be regenerated if this run of deflate switches away from Huffman.)
 */
local block_state deflate_huff(s, flush)
    deflate_state *s;
    int flush;
{
    int bflush;             /* set if current block must be flushed */

    for (;;) {
        /* Make sure that we have a literal to write. */
        if (s->lookahead == 0) {
            fill_window(s);
            if (s->lookahead == 0) {