Aminet 1/Aminet - June 1993 [Walnut Creek].iso/usenet/sources/volume90/unix/flex_2_3/part05

Internet Message Format | 1990-08-19 | 55.2 KB

Path: abcfd20.larc.nasa.gov!amiga-request
From: [e-mail] (Amiga Sources/Binaries Moderator)
Subject: v90i232: flex 2.3 - fast lexical analyzer generator, Part05/13
Reply-To: [e-mail] (William P Loftus)
Newsgroups: comp.sources.amiga
Message-ID: <comp.sources.amiga:[e-mail]>
Date: 19 Aug 90 22:42:32 GMT
Approved: [e-mail] (Tad Guy)
X-Mail-Submissions-To: [e-mail]
X-Post-Discussions-To: comp.sys.amiga

Submitted-by: [e-mail] (William P Loftus)
Posting-number: Volume 90, Issue 232
Archive-name: unix/flex-2.3/part05

#!/bin/sh
# This is a shell archive.  Remove anything before this line, then unpack
# it by saving it into a file and typing "sh file".  To overwrite existing
# files, type "sh file -c".  You can also feed this as standard input via
# unshar, or by typing "sh <file", e.g..  If this archive is complete, you
# will see the following message at the end:
#        "End of archive 5 (of 13)."
# Contents:  dfa.c flex.Doc
# Wrapped by tadguy@abcfd20 on Sun Aug 19 18:41:44 1990
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f 'dfa.c' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'dfa.c'\"
else
echo shar: Extracting \"'dfa.c'\" \(26919 characters\)
sed "s/^X//" >'dfa.c' <<'END_OF_FILE'
X/* dfa - DFA construction routines */
X
X/*-
X * Copyright (c) 1990 The Regents of the University of California.
X * All rights reserved.
X *
X * This code is derived from software contributed to Berkeley by
X * Vern Paxson.
X *
X * The United States Government has rights in this work pursuant
X * to contract no. DE-AC03-76SF00098 between the United States
X * Department of Energy and the University of California.
X *
X * Redistribution and use in source and binary forms are permitted provided
X * that: (1) source distributions retain this entire copyright notice and
X * comment, and (2) distributions including binaries display the following
X * acknowledgement:  ``This product includes software developed by the
X * University of California, Berkeley and its contributors'' in the
X * documentation or other materials provided with the distribution and in
X * all advertising materials mentioning features or use of this software.
X * Neither the name of the University nor the names of its contributors may
X * be used to endorse or promote products derived from this software without
X * specific prior written permission.
X * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
X * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
X * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
X */
X
X#ifndef lint
Xstatic char rcsid[] =
X    "@(#) $Header: /usr/fsys/odin/a/vern/flex/RCS/dfa.c,v 2.7 90/06/27 23:48:15 vern Exp $ (LBL)";
X#endif
X
X#include "flexdef.h"
X
X
X/* declare functions that have forward references */
X
Xvoid dump_associated_rules PROTO((FILE*, int));
Xvoid dump_transitions PROTO((FILE*, int[]));
Xvoid sympartition PROTO((int[], int, int[], int[]));
Xint symfollowset PROTO((int[], int, int, int[]));
X
X
X/* check_for_backtracking - check a DFA state for backtracking
X *
X * synopsis
X *     int ds, state[numecs];
X *     check_for_backtracking( ds, state );
X *
X * ds is the number of the state to check and state[] is its out-transitions,
X * indexed by equivalence class, and state_rules[] is the set of rules
X * associated with this state
X */
X
Xvoid check_for_backtracking( ds, state )
Xint ds;
Xint state[];
X
X    {
X    if ( (reject && ! dfaacc[ds].dfaacc_set) || ! dfaacc[ds].dfaacc_state )
X    { /* state is non-accepting */
X    ++num_backtracking;
X
X    if ( backtrack_report )
X        {
X        fprintf( backtrack_file, "State #%d is non-accepting -\n", ds );
X
X        /* identify the state */
X        dump_associated_rules( backtrack_file, ds );
X
X        /* now identify it further using the out- and jam-transitions */
X        dump_transitions( backtrack_file, state );
X
X        putc( '\n', backtrack_file );
X        }
X    }
X    }
X
X
X/* check_trailing_context - check to see if NFA state set constitutes
X *                          "dangerous" trailing context
X *
X * synopsis
X *    int nfa_states[num_states+1], num_states;
X *    int accset[nacc+1], nacc;
X *    check_trailing_context( nfa_states, num_states, accset, nacc );
X *
X * NOTES
X *    Trailing context is "dangerous" if both the head and the trailing
X *  part are of variable size \and/ there's a DFA state which contains
X *  both an accepting state for the head part of the rule and NFA states
X *  which occur after the beginning of the trailing context.
X *  When such a rule is matched, it's impossible to tell if having been
X *  in the DFA state indicates the beginning of the trailing context
X *  or further-along scanning of the pattern.  In these cases, a warning
X *  message is issued.
X *
X *    nfa_states[1 .. num_states] is the list of NFA states in the DFA.
X *    accset[1 .. nacc] is the list of accepting numbers for the DFA state.
X */
X
Xvoid check_trailing_context( nfa_states, num_states, accset, nacc )
Xint *nfa_states, num_states;
Xint *accset;
Xregister int nacc;
X
X    {
X    register int i, j;
X
X    for ( i = 1; i <= num_states; ++i )
X    {
X    int ns = nfa_states[i];
X    register int type = state_type[ns];
X    register int ar = assoc_rule[ns];
X
X    if ( type == STATE_NORMAL || rule_type[ar] != RULE_VARIABLE )
X        { /* do nothing */
X        }
X
X    else if ( type == STATE_TRAILING_CONTEXT )
X        {
X        /* potential trouble.  Scan set of accepting numbers for
X         * the one marking the end of the "head".  We assume that
X         * this looping will be fairly cheap since it's rare that
X         * an accepting number set is large.
X         */
X        for ( j = 1; j <= nacc; ++j )
X        if ( accset[j] & YY_TRAILING_HEAD_MASK )
X            {
X            fprintf( stderr,
X             "%s: Dangerous trailing context in rule at line %d\n",
X                 program_name, rule_linenum[ar] );
X            return;
X            }
X        }
X    }
X    }
X
X
X/* dump_associated_rules - list the rules associated with a DFA state
X *
X * synopisis
X *     int ds;
X *     FILE *file;
X *     dump_associated_rules( file, ds );
X *
X * goes through the set of NFA states associated with the DFA and
X * extracts the first MAX_ASSOC_RULES unique rules, sorts them,
X * and writes a report to the given file
X */
X
Xvoid dump_associated_rules( file, ds )
XFILE *file;
Xint ds;
X
X    {
X    register int i, j;
X    register int num_associated_rules = 0;
X    int rule_set[MAX_ASSOC_RULES + 1];
X    int *dset = dss[ds];
X    int size = dfasiz[ds];
X
X    for ( i = 1; i <= size; ++i )
X    {
X    register rule_num = rule_linenum[assoc_rule[dset[i]]];
X
X    for ( j = 1; j <= num_associated_rules; ++j )
X        if ( rule_num == rule_set[j] )
X        break;
X
X    if ( j > num_associated_rules )
X        { /* new rule */
X        if ( num_associated_rules < MAX_ASSOC_RULES )
X        rule_set[++num_associated_rules] = rule_num;
X        }
X    }
X
X    bubble( rule_set, num_associated_rules );
X
X    fprintf( file, " associated rule line numbers:" );
X
X    for ( i = 1; i <= num_associated_rules; ++i )
X    {
X    if ( i % 8 == 1 )
X        putc( '\n', file );
X
X    fprintf( file, "\t%d", rule_set[i] );
X    }
X
X    putc( '\n', file );
X    }
X
X
X/* dump_transitions - list the transitions associated with a DFA state
X *
X * synopisis
X *     int state[numecs];
X *     FILE *file;
X *     dump_transitions( file, state );
X *
X * goes through the set of out-transitions and lists them in human-readable
X * form (i.e., not as equivalence classes); also lists jam transitions
X * (i.e., all those which are not out-transitions, plus EOF).  The dump
X * is done to the given file.
X */
X
Xvoid dump_transitions( file, state )
XFILE *file;
Xint state[];
X
X    {
X    register int i, ec;
X    int out_char_set[CSIZE];
X
X    for ( i = 0; i < csize; ++i )
X    {
X    ec = abs( ecgroup[i] );
X    out_char_set[i] = state[ec];
X    }
X
X    fprintf( file, " out-transitions: " );
X
X    list_character_set( file, out_char_set );
X
X    /* now invert the members of the set to get the jam transitions */
X    for ( i = 0; i < csize; ++i )
X    out_char_set[i] = ! out_char_set[i];
X
X    fprintf( file, "\n jam-transitions: EOF " );
X
X    list_character_set( file, out_char_set );
X
X    putc( '\n', file );
X    }
X
X
X/* epsclosure - construct the epsilon closure of a set of ndfa states
X *
X * synopsis
X *    int t[current_max_dfa_size], numstates, accset[num_rules + 1], nacc;
X *    int hashval;
X *    int *epsclosure();
X *    t = epsclosure( t, &numstates, accset, &nacc, &hashval );
X *
X * NOTES
X *    the epsilon closure is the set of all states reachable by an arbitrary
X *  number of epsilon transitions which themselves do not have epsilon
X *  transitions going out, unioned with the set of states which have non-null
X *  accepting numbers.  t is an array of size numstates of nfa state numbers.
X *  Upon return, t holds the epsilon closure and numstates is updated.  accset
X *  holds a list of the accepting numbers, and the size of accset is given
X *  by nacc.  t may be subjected to reallocation if it is not large enough
X *  to hold the epsilon closure.
X *
X *    hashval is the hash value for the dfa corresponding to the state set
X */
X
Xint *epsclosure( t, ns_addr, accset, nacc_addr, hv_addr )
Xint *t, *ns_addr, accset[], *nacc_addr, *hv_addr;
X
X    {
X    register int stkpos, ns, tsp;
X    int numstates = *ns_addr, nacc, hashval, transsym, nfaccnum;
X    int stkend, nstate;
X    static int did_stk_init = false, *stk;
X
X#define MARK_STATE(state) \
X    trans1[state] = trans1[state] - MARKER_DIFFERENCE;
X
X#define IS_MARKED(state) (trans1[state] < 0)
X
X#define UNMARK_STATE(state) \
X    trans1[state] = trans1[state] + MARKER_DIFFERENCE;
X
X#define CHECK_ACCEPT(state) \
X    { \
X    nfaccnum = accptnum[state]; \
X    if ( nfaccnum != NIL ) \
X        accset[++nacc] = nfaccnum; \
X    }
X
X#define DO_REALLOCATION \
X    { \
X    current_max_dfa_size += MAX_DFA_SIZE_INCREMENT; \
X    ++num_reallocs; \
X    t = reallocate_integer_array( t, current_max_dfa_size ); \
X    stk = reallocate_integer_array( stk, current_max_dfa_size ); \
X    } \
X
X#define PUT_ON_STACK(state) \
X    { \
X    if ( ++stkend >= current_max_dfa_size ) \
X        DO_REALLOCATION \
X    stk[stkend] = state; \
X    MARK_STATE(state) \
X    }
X
X#define ADD_STATE(state) \
X    { \
X    if ( ++numstates >= current_max_dfa_size ) \
X        DO_REALLOCATION \
X    t[numstates] = state; \
X    hashval = hashval + state; \
X    }
X
X#define STACK_STATE(state) \
X    { \
X    PUT_ON_STACK(state) \
X    CHECK_ACCEPT(state) \
X    if ( nfaccnum != NIL || transchar[state] != SYM_EPSILON ) \
X        ADD_STATE(state) \
X    }
X
X    if ( ! did_stk_init )
X    {
X    stk = allocate_integer_array( current_max_dfa_size );
X    did_stk_init = true;
X    }
X
X    nacc = stkend = hashval = 0;
X
X    for ( nstate = 1; nstate <= numstates; ++nstate )
X    {
X    ns = t[nstate];
X
X    /* the state could be marked if we've already pushed it onto
X     * the stack
X     */
X    if ( ! IS_MARKED(ns) )
X        PUT_ON_STACK(ns)
X
X    CHECK_ACCEPT(ns)
X    hashval = hashval + ns;
X    }
X
X    for ( stkpos = 1; stkpos <= stkend; ++stkpos )
X    {
X    ns = stk[stkpos];
X    transsym = transchar[ns];
X
X    if ( transsym == SYM_EPSILON )
X        {
X        tsp = trans1[ns] + MARKER_DIFFERENCE;
X
X        if ( tsp != NO_TRANSITION )
X        {
X        if ( ! IS_MARKED(tsp) )
X            STACK_STATE(tsp)
X
X        tsp = trans2[ns];
X
X        if ( tsp != NO_TRANSITION )
X            if ( ! IS_MARKED(tsp) )
X            STACK_STATE(tsp)
X        }
X        }
X    }
X
X    /* clear out "visit" markers */
X
X    for ( stkpos = 1; stkpos <= stkend; ++stkpos )
X    {
X    if ( IS_MARKED(stk[stkpos]) )
X        {
X        UNMARK_STATE(stk[stkpos])
X        }
X    else
X        flexfatal( "consistency check failed in epsclosure()" );
X    }
X
X    *ns_addr = numstates;
X    *hv_addr = hashval;
X    *nacc_addr = nacc;
X
X    return ( t );
X    }
X
X
X/* increase_max_dfas - increase the maximum number of DFAs */
X
Xvoid increase_max_dfas()
X
X    {
X    current_max_dfas += MAX_DFAS_INCREMENT;
X
X    ++num_reallocs;
X
X    base = reallocate_integer_array( base, current_max_dfas );
X    def = reallocate_integer_array( def, current_max_dfas );
X    dfasiz = reallocate_integer_array( dfasiz, current_max_dfas );
X    accsiz = reallocate_integer_array( accsiz, current_max_dfas );
X    dhash = reallocate_integer_array( dhash, current_max_dfas );
X    dss = reallocate_int_ptr_array( dss, current_max_dfas );
X    dfaacc = reallocate_dfaacc_union( dfaacc, current_max_dfas );
X
X    if ( nultrans )
X    nultrans = reallocate_integer_array( nultrans, current_max_dfas );
X    }
X
X
X/* ntod - convert an ndfa to a dfa
X *
X * synopsis
X *    ntod();
X *
X *  creates the dfa corresponding to the ndfa we've constructed.  the
X *  dfa starts out in state #1.
X */
X
Xvoid ntod()
X
X    {
X    int *accset, ds, nacc, newds;
X    int sym, hashval, numstates, dsize;
X    int num_full_table_rows;    /* used only for -f */
X    int *nset, *dset;
X    int targptr, totaltrans, i, comstate, comfreq, targ;
X    int *epsclosure(), snstods(), symlist[CSIZE + 1];
X    int num_start_states;
X    int todo_head, todo_next;
X
X    /* note that the following are indexed by *equivalence classes*
X     * and not by characters.  Since equivalence classes are indexed
X     * beginning with 1, even if the scanner accepts NUL's, this
X     * means that (since every character is potentially in its own
X     * equivalence class) these arrays must have room for indices
X     * from 1 to CSIZE, so their size must be CSIZE + 1.
X     */
X    int duplist[CSIZE + 1], state[CSIZE + 1];
X    int targfreq[CSIZE + 1], targstate[CSIZE + 1];
X
X    /* this is so find_table_space(...) will know where to start looking in
X     * chk/nxt for unused records for space to put in the state
X     */
X    if ( fullspd )
X    firstfree = 0;
X
X    accset = allocate_integer_array( num_rules + 1 );
X    nset = allocate_integer_array( current_max_dfa_size );
X
X    /* the "todo" queue is represented by the head, which is the DFA
X     * state currently being processed, and the "next", which is the
X     * next DFA state number available (not in use).  We depend on the
X     * fact that snstods() returns DFA's \in increasing order/, and thus
X     * need only know the bounds of the dfas to be processed.
X     */
X    todo_head = todo_next = 0;
X
X    for ( i = 0; i <= csize; ++i )
X    {
X    duplist[i] = NIL;
X    symlist[i] = false;
X    }
X
X    for ( i = 0; i <= num_rules; ++i )
X    accset[i] = NIL;
X
X    if ( trace )
X    {
X    dumpnfa( scset[1] );
X    fputs( "\n\nDFA Dump:\n\n", stderr );
X    }
X
X    inittbl();
X
X    /* check to see whether we should build a separate table for transitions
X     * on NUL characters.  We don't do this for full-speed (-F) scanners,
X     * since for them we don't have a simple state number lying around with
X     * which to index the table.  We also don't bother doing it for scanners
X     * unless (1) NUL is in its own equivalence class (indicated by a
X     * positive value of ecgroup[NUL]), (2) NUL's equilvalence class is
X     * the last equivalence class, and (3) the number of equivalence classes
X     * is the same as the number of characters.  This latter case comes about
X     * when useecs is false or when its true but every character still
X     * manages to land in its own class (unlikely, but it's cheap to check
X     * for).  If all these things are true then the character code needed
X     * to represent NUL's equivalence class for indexing the tables is
X     * going to take one more bit than the number of characters, and therefore
X     * we won't be assured of being able to fit it into a YY_CHAR variable.
X     * This rules out storing the transitions in a compressed table, since
X     * the code for interpreting them uses a YY_CHAR variable (perhaps it
X     * should just use an integer, though; this is worth pondering ... ###).
X     *
X     * Finally, for full tables, we want the number of entries in the
X     * table to be a power of two so the array references go fast (it
X     * will just take a shift to compute the major index).  If encoding
X     * NUL's transitions in the table will spoil this, we give it its
X     * own table (note that this will be the case if we're not using
X     * equivalence classes).
X     */
X
X    /* note that the test for ecgroup[0] == numecs below accomplishes
X     * both (1) and (2) above
X     */
X    if ( ! fullspd && ecgroup[0] == numecs )
X    { /* NUL is alone in its equivalence class, which is the last one */
X    int use_NUL_table = (numecs == csize);
X
X    if ( fulltbl && ! use_NUL_table )
X        { /* we still may want to use the table if numecs is a power of 2 */
X        int power_of_two;
X
X        for ( power_of_two = 1; power_of_two <= csize; power_of_two *= 2 )
X        if ( numecs == power_of_two )
X            {
X            use_NUL_table = true;
X            break;
X            }
X        }
X
X    if ( use_NUL_table )
X        nultrans = allocate_integer_array( current_max_dfas );
X        /* from now on, nultrans != nil indicates that we're
X         * saving null transitions for later, separate encoding
X         */
X    }
X
X
X    if ( fullspd )
X    {
X    for ( i = 0; i <= numecs; ++i )
X        state[i] = 0;
X    place_state( state, 0, 0 );
X    }
X
X    else if ( fulltbl )
X    {
X    if ( nultrans )
X        /* we won't be including NUL's transitions in the table,
X         * so build it for entries from 0 .. numecs - 1
X         */
X        num_full_table_rows = numecs;
X
X    else
X        /* take into account the fact that we'll be including
X         * the NUL entries in the transition table.  Build it
X         * from 0 .. numecs.
X         */
X        num_full_table_rows = numecs + 1;
X
X    /* declare it "short" because it's a real long-shot that that
X     * won't be large enough.
X     */
X    printf( "static short int yy_nxt[][%d] =\n    {\n",
X        /* '}' so vi doesn't get too confused */
X        num_full_table_rows );
X
X    /* generate 0 entries for state #0 */
X    for ( i = 0; i < num_full_table_rows; ++i )
X        mk2data( 0 );
X
X    /* force ',' and dataflush() next call to mk2data */
X    datapos = NUMDATAITEMS;
X
X    /* force extra blank line next dataflush() */
X    dataline = NUMDATALINES;
X    }
X
X    /* create the first states */
X
X    num_start_states = lastsc * 2;
X
X    for ( i = 1; i <= num_start_states; ++i )
X    {
X    numstates = 1;
X
X    /* for each start condition, make one state for the case when
X     * we're at the beginning of the line (the '%' operator) and
X     * one for the case when we're not
X     */
X    if ( i % 2 == 1 )
X        nset[numstates] = scset[(i / 2) + 1];
X    else
X        nset[numstates] = mkbranch( scbol[i / 2], scset[i / 2] );
X
X    nset = epsclosure( nset, &numstates, accset, &nacc, &hashval );
X
X    if ( snstods( nset, numstates, accset, nacc, hashval, &ds ) )
X        {
X        numas += nacc;
X        totnst += numstates;
X        ++todo_next;
X
X        if ( variable_trailing_context_rules && nacc > 0 )
X        check_trailing_context( nset, numstates, accset, nacc );
X        }
X    }
X
X    if ( ! fullspd )
X    {
X    if ( ! snstods( nset, 0, accset, 0, 0, &end_of_buffer_state ) )
X        flexfatal( "could not create unique end-of-buffer state" );
X
X    ++numas;
X    ++num_start_states;
X    ++todo_next;
X    }
X
X    while ( todo_head < todo_next )
X    {
X    targptr = 0;
X    totaltrans = 0;
X
X    for ( i = 1; i <= numecs; ++i )
X        state[i] = 0;
X
X    ds = ++todo_head;
X
X    dset = dss[ds];
X    dsize = dfasiz[ds];
X
X    if ( trace )
X        fprintf( stderr, "state # %d:\n", ds );
X
X    sympartition( dset, dsize, symlist, duplist );
X
X    for ( sym = 1; sym <= numecs; ++sym )
X        {
X        if ( symlist[sym] )
X        {
X        symlist[sym] = 0;
X
X        if ( duplist[sym] == NIL )
X            { /* symbol has unique out-transitions */
X            numstates = symfollowset( dset, dsize, sym, nset );
X            nset = epsclosure( nset, &numstates, accset,
X                       &nacc, &hashval );
X
X            if ( snstods( nset, numstates, accset,
X                  nacc, hashval, &newds ) )
X            {
X            totnst = totnst + numstates;
X            ++todo_next;
X            numas += nacc;
X
X            if ( variable_trailing_context_rules && nacc > 0 )
X                check_trailing_context( nset, numstates,
X                accset, nacc );
X            }
X
X            state[sym] = newds;
X
X            if ( trace )
X            fprintf( stderr, "\t%d\t%d\n", sym, newds );
X
X            targfreq[++targptr] = 1;
X            targstate[targptr] = newds;
X            ++numuniq;
X            }
X
X        else
X            {
X            /* sym's equivalence class has the same transitions
X             * as duplist(sym)'s equivalence class
X             */
X            targ = state[duplist[sym]];
X            state[sym] = targ;
X
X            if ( trace )
X            fprintf( stderr, "\t%d\t%d\n", sym, targ );
X
X            /* update frequency count for destination state */
X
X            i = 0;
X            while ( targstate[++i] != targ )
X            ;
X
X            ++targfreq[i];
X            ++numdup;
X            }
X
X        ++totaltrans;
X        duplist[sym] = NIL;
X        }
X        }
X
X    numsnpairs = numsnpairs + totaltrans;
X
X    if ( caseins && ! useecs )
X        {
X        register int j;
X
X        for ( i = 'A', j = 'a'; i <= 'Z'; ++i, ++j )
X        state[i] = state[j];
X        }
X
X    if ( ds > num_start_states )
X        check_for_backtracking( ds, state );
X
X    if ( nultrans )
X        {
X        nultrans[ds] = state[NUL_ec];
X        state[NUL_ec] = 0;    /* remove transition */
X        }
X
X    if ( fulltbl )
X        {
X        /* supply array's 0-element */
X        if ( ds == end_of_buffer_state )
X        mk2data( -end_of_buffer_state );
X        else
X        mk2data( end_of_buffer_state );
X
X        for ( i = 1; i < num_full_table_rows; ++i )
X        /* jams are marked by negative of state number */
X        mk2data( state[i] ? state[i] : -ds );
X
X        /* force ',' and dataflush() next call to mk2data */
X        datapos = NUMDATAITEMS;
X
X        /* force extra blank line next dataflush() */
X        dataline = NUMDATALINES;
X        }
X
X        else if ( fullspd )
X        place_state( state, ds, totaltrans );
X
X    else if ( ds == end_of_buffer_state )
X        /* special case this state to make sure it does what it's
X         * supposed to, i.e., jam on end-of-buffer
X         */
X        stack1( ds, 0, 0, JAMSTATE );
X
X    else /* normal, compressed state */
X        {
X        /* determine which destination state is the most common, and
X         * how many transitions to it there are
X         */
X
X        comfreq = 0;
X        comstate = 0;
X
X        for ( i = 1; i <= targptr; ++i )
X        if ( targfreq[i] > comfreq )
X            {
X            comfreq = targfreq[i];
X            comstate = targstate[i];
X            }
X
X        bldtbl( state, ds, totaltrans, comstate, comfreq );
X        }
X    }
X
X    if ( fulltbl )
X    dataend();
X
X    else if ( ! fullspd )
X    {
X    cmptmps();  /* create compressed template entries */
X
X    /* create tables for all the states with only one out-transition */
X    while ( onesp > 0 )
X        {
X        mk1tbl( onestate[onesp], onesym[onesp], onenext[onesp],
X            onedef[onesp] );
X        --onesp;
X        }
X
X    mkdeftbl();
X    }
X    }
X
X
X/* snstods - converts a set of ndfa states into a dfa state
X *
X * synopsis
X *    int sns[numstates], numstates, newds, accset[num_rules + 1], nacc, hashval;
X *    int snstods();
X *    is_new_state = snstods( sns, numstates, accset, nacc, hashval, &newds );
X *
X * on return, the dfa state number is in newds.
X */
X
Xint snstods( sns, numstates, accset, nacc, hashval, newds_addr )
Xint sns[], numstates, accset[], nacc, hashval, *newds_addr;
X
X    {
X    int didsort = 0;
X    register int i, j;
X    int newds, *oldsns;
X
X    for ( i = 1; i <= lastdfa; ++i )
X    if ( hashval == dhash[i] )
X        {
X        if ( numstates == dfasiz[i] )
X        {
X        oldsns = dss[i];
X
X        if ( ! didsort )
X            {
X            /* we sort the states in sns so we can compare it to
X             * oldsns quickly.  we use bubble because there probably
X             * aren't very many states
X             */
X            bubble( sns, numstates );
X            didsort = 1;
X            }
X
X        for ( j = 1; j <= numstates; ++j )
X            if ( sns[j] != oldsns[j] )
X            break;
X
X        if ( j > numstates )
X            {
X            ++dfaeql;
X            *newds_addr = i;
X            return ( 0 );
X            }
X
X        ++hshcol;
X        }
X
X        else
X        ++hshsave;
X        }
X
X    /* make a new dfa */
X
X    if ( ++lastdfa >= current_max_dfas )
X    increase_max_dfas();
X
X    newds = lastdfa;
X
X    dss[newds] = (int *) malloc( (unsigned) ((numstates + 1) * sizeof( int )) );
X
X    if ( ! dss[newds] )
X    flexfatal( "dynamic memory failure in snstods()" );
X
X    /* if we haven't already sorted the states in sns, we do so now, so that
X     * future comparisons with it can be made quickly
X     */
X
X    if ( ! didsort )
X    bubble( sns, numstates );
X
X    for ( i = 1; i <= numstates; ++i )
X    dss[newds][i] = sns[i];
X
X    dfasiz[newds] = numstates;
X    dhash[newds] = hashval;
X
X    if ( nacc == 0 )
X    {
X    if ( reject )
X        dfaacc[newds].dfaacc_set = (int *) 0;
X    else
X        dfaacc[newds].dfaacc_state = 0;
X
X    accsiz[newds] = 0;
X    }
X
X    else if ( reject )
X    {
X    /* we sort the accepting set in increasing order so the disambiguating
X     * rule that the first rule listed is considered match in the event of
X     * ties will work.  We use a bubble sort since the list is probably
X     * quite small.
X     */
X
X    bubble( accset, nacc );
X
X    dfaacc[newds].dfaacc_set =
X        (int *) malloc( (unsigned) ((nacc + 1) * sizeof( int )) );
X
X    if ( ! dfaacc[newds].dfaacc_set )
X        flexfatal( "dynamic memory failure in snstods()" );
X
X    /* save the accepting set for later */
X    for ( i = 1; i <= nacc; ++i )
X        dfaacc[newds].dfaacc_set[i] = accset[i];
X
X    accsiz[newds] = nacc;
X    }
X
X    else
X    { /* find lowest numbered rule so the disambiguating rule will work */
X    j = num_rules + 1;
X
X    for ( i = 1; i <= nacc; ++i )
X        if ( accset[i] < j )
X        j = accset[i];
X
X    dfaacc[newds].dfaacc_state = j;
X    }
X
X    *newds_addr = newds;
X
X    return ( 1 );
X    }
X
X
X/* symfollowset - follow the symbol transitions one step
X *
X * synopsis
X *    int ds[current_max_dfa_size], dsize, transsym;
X *    int nset[current_max_dfa_size], numstates;
X *    numstates = symfollowset( ds, dsize, transsym, nset );
X */
X
Xint symfollowset( ds, dsize, transsym, nset )
Xint ds[], dsize, transsym, nset[];
X
X    {
X    int ns, tsp, sym, i, j, lenccl, ch, numstates;
X    int ccllist;
X
X    numstates = 0;
X
X    for ( i = 1; i <= dsize; ++i )
X    { /* for each nfa state ns in the state set of ds */
X    ns = ds[i];
X    sym = transchar[ns];
X    tsp = trans1[ns];
X
X    if ( sym < 0 )
X        { /* it's a character class */
X        sym = -sym;
X        ccllist = cclmap[sym];
X        lenccl = ccllen[sym];
X
X        if ( cclng[sym] )
X        {
X        for ( j = 0; j < lenccl; ++j )
X            { /* loop through negated character class */
X            ch = ccltbl[ccllist + j];
X
X            if ( ch == 0 )
X            ch = NUL_ec;
X
X            if ( ch > transsym )
X            break;    /* transsym isn't in negated ccl */
X
X            else if ( ch == transsym )
X            /* next 2 */ goto bottom;
X            }
X
X        /* didn't find transsym in ccl */
X        nset[++numstates] = tsp;
X        }
X
X        else
X        for ( j = 0; j < lenccl; ++j )
X            {
X            ch = ccltbl[ccllist + j];
X
X            if ( ch == 0 )
X            ch = NUL_ec;
X
X            if ( ch > transsym )
X            break;
X
X            else if ( ch == transsym )
X            {
X            nset[++numstates] = tsp;
X            break;
X            }
X            }
X        }
X
X    else if ( sym >= 'A' && sym <= 'Z' && caseins )
X        flexfatal( "consistency check failed in symfollowset" );
X
X    else if ( sym == SYM_EPSILON )
X        { /* do nothing */
X        }
X
X    else if ( abs( ecgroup[sym] ) == transsym )
X        nset[++numstates] = tsp;
X
Xbottom:
X    ;
X    }
X
X    return ( numstates );
X    }
X
X
X/* sympartition - partition characters with same out-transitions
X *
X * synopsis
X *    integer ds[current_max_dfa_size], numstates, duplist[numecs];
X *    symlist[numecs];
X *    sympartition( ds, numstates, symlist, duplist );
X */
X
Xvoid sympartition( ds, numstates, symlist, duplist )
Xint ds[], numstates, duplist[];
Xint symlist[];
X
X    {
X    int tch, i, j, k, ns, dupfwd[CSIZE + 1], lenccl, cclp, ich;
X
X    /* partitioning is done by creating equivalence classes for those
X     * characters which have out-transitions from the given state.  Thus
X     * we are really creating equivalence classes of equivalence classes.
X     */
X
X    for ( i = 1; i <= numecs; ++i )
X    { /* initialize equivalence class list */
X    duplist[i] = i - 1;
X    dupfwd[i] = i + 1;
X    }
X
X    duplist[1] = NIL;
X    dupfwd[numecs] = NIL;
X
X    for ( i = 1; i <= numstates; ++i )
X    {
X    ns = ds[i];
X    tch = transchar[ns];
X
X    if ( tch != SYM_EPSILON )
X        {
X        if ( tch < -lastccl || tch > csize )
X        {
X        if ( tch > csize && tch <= CSIZE )
X            flexerror( "scanner requires -8 flag" );
X
X        else
X            flexfatal(
X            "bad transition character detected in sympartition()" );
X        }
X
X        if ( tch >= 0 )
X        { /* character transition */
X        /* abs() needed for fake %t ec's */
X        int ec = abs( ecgroup[tch] );
X
X        mkechar( ec, dupfwd, duplist );
X        symlist[ec] = 1;
X        }
X
X        else
X        { /* character class */
X        tch = -tch;
X
X        lenccl = ccllen[tch];
X        cclp = cclmap[tch];
X        mkeccl( ccltbl + cclp, lenccl, dupfwd, duplist, numecs,
X            NUL_ec );
X
X        if ( cclng[tch] )
X            {
X            j = 0;
X
X            for ( k = 0; k < lenccl; ++k )
X            {
X            ich = ccltbl[cclp + k];
X
X            if ( ich == 0 )
X                ich = NUL_ec;
X
X            for ( ++j; j < ich; ++j )
X                symlist[j] = 1;
X            }
X
X            for ( ++j; j <= numecs; ++j )
X            symlist[j] = 1;
X            }
X
X        else
X            for ( k = 0; k < lenccl; ++k )
X            {
X            ich = ccltbl[cclp + k];
X
X            if ( ich == 0 )
X                ich = NUL_ec;
X
X            symlist[ich] = 1;
X            }
X        }
X        }
X    }
X    }
END_OF_FILE
if test 26919 -ne `wc -c <'dfa.c'`; then
    echo shar: \"'dfa.c'\" unpacked with wrong size!
fi
# end of 'dfa.c'
fi
if test -f 'flex.Doc' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'flex.Doc'\"
else
echo shar: Extracting \"'flex.Doc'\" \(25372 characters\)
sed "s/^X//" >'flex.Doc' <<'END_OF_FILE'
X
X
X
XFLEX(1)                   USER COMMANDS                   FLEX(1)
X
X
X
XNAME
X     flex - fast lexical analyzer generator
X
XSYNOPSIS
X     flex [-bcdfinpstvFILT8 -C[efmF] -Sskeleton] [filename ...]
X
XDESCRIPTION
X     flex is a  tool  for  generating  scanners:  programs  which
X     recognized  lexical  patterns in text.  flex reads the given
X     input files, or its standard input  if  no  file  names  are
X     given,  for  a  description  of  a scanner to generate.  The
X     description is in the form of pairs of  regular  expressions
X     and  C  code,  called  rules.  flex  generates as output a C
X     source file, lex.yy.c, which defines a routine yylex(). This
X     file is compiled and linked with the -lfl library to produce
X     an executable.  When the executable is run, it analyzes  its
X     input  for occurrences of the regular expressions.  Whenever
X     it finds one, it executes the corresponding C code.
X
X     For full documentation, see flexdoc(1). This manual entry is
X     intended for use as a quick reference.
X
XOPTIONS
X     flex has the following options:
X
X     -b   Generate  backtracking  information  to  lex.backtrack.
X          This  is  a  list of scanner states which require back-
X          tracking and the input characters on which they do  so.
X          By adding rules one can remove backtracking states.  If
X          all backtracking states are eliminated and -f or -F  is
X          used, the generated scanner will run faster.
X
X     -c   is a do-nothing, deprecated option included  for  POSIX
X          compliance.
X
X          NOTE: in previous releases of flex -c specified  table-
X          compression  options.   This functionality is now given
X          by the -C flag.  To ease the the impact of this change,
X          when  flex encounters -c, it currently issues a warning
X          message and assumes that -C was  desired  instead.   In
X          the future this "promotion" of -c to -C will go away in
X          the name of full POSIX  compliance  (unless  the  POSIX
X          meaning is removed first).
X
X     -d   makes the generated scanner run in debug  mode.   When-
X          ever   a   pattern   is   recognized   and  the  global
X          yy_flex_debug is non-zero (which is the  default),  the
X          scanner will write to stderr a line of the form:
X
X              --accepting rule at line 53 ("the matched text")
X
X          The line number refers to the location of the  rule  in
X
X
X
XVersion 2.3         Last change: 26 May 1990                    1
X
X
X
X
X
X
XFLEX(1)                   USER COMMANDS                   FLEX(1)
X
X
X
X          the  file defining the scanner (i.e., the file that was
X          fed to flex).  Messages are  also  generated  when  the
X          scanner  backtracks,  accepts the default rule, reaches
X          the end of its input buffer (or encounters a  NUL;  the
X          two  look  the same as far as the scanner's concerned),
X          or reaches an end-of-file.
X
X     -f   specifies (take your pick) full table or fast  scanner.
X          No  table compression is done.  The result is large but
X          fast.  This option is equivalent to -Cf (see below).
X
X     -i   instructs flex to generate a case-insensitive  scanner.
X          The  case  of  letters given in the flex input patterns
X          will be ignored,  and  tokens  in  the  input  will  be
X          matched  regardless of case.  The matched text given in
X          yytext will have the preserved case (i.e., it will  not
X          be folded).
X
X     -n   is another do-nothing, deprecated option included  only
X          for POSIX compliance.
X
X     -p   generates a performance report to stderr.   The  report
X          consists  of  comments  regarding  features of the flex
X          input file which will cause a loss  of  performance  in
X          the resulting scanner.
X
X     -s   causes the default rule (that unmatched  scanner  input
X          is  echoed to stdout) to be suppressed.  If the scanner
X          encounters input that does not match any of its  rules,
X          it aborts with an error.
X
X     -t   instructs flex to write the  scanner  it  generates  to
X          standard output instead of lex.yy.c.
X
X     -v   specifies that flex should write to stderr a summary of
X          statistics regarding the scanner it generates.
X
X     -F   specifies that the fast  scanner  table  representation
X          should  be  used.  This representation is about as fast
X          as the full table representation  (-f),  and  for  some
X          sets  of patterns will be considerably smaller (and for
X          others, larger).  See flexdoc(1) for details.
X
X          This option is equivalent to -CF (see below).
X
X     -I   instructs flex to generate an interactive scanner, that
X          is, a scanner which stops immediately rather than look-
X          ing ahead if it knows that the currently  scanned  text
X          cannot  be  part  of a longer rule's match.  Again, see
X          flexdoc(1) for details.
X
X          Note, -I cannot be used in  conjunction  with  full  or
X
X
X
XVersion 2.3         Last change: 26 May 1990                    2
X
X
X
X
X
X
XFLEX(1)                   USER COMMANDS                   FLEX(1)
X
X
X
X          fast tables, i.e., the -f, -F, -Cf, or -CF flags.
X
X     -L   instructs flex not  to  generate  #line  directives  in
X          lex.yy.c. The default is to generate such directives so
X          error messages in the actions will be correctly located
X          with  respect  to the original flex input file, and not
X          to the fairly meaningless line numbers of lex.yy.c.
X
X     -T   makes flex run in trace mode.  It will generate  a  lot
X          of  messages to stdout concerning the form of the input
X          and the resultant non-deterministic  and  deterministic
X          finite  automata.   This  option  is  mostly for use in
X          maintaining flex.
X
X     -8   instructs flex to generate an 8-bit scanner.   On  some
X          sites,  this is the default.  On others, the default is
X          7-bit characters.  To see which is the case, check  the
X          verbose  (-v) output for "equivalence classes created".
X          If the denominator of the number shown is 128, then  by
X          default  flex is generating 7-bit characters.  If it is
X          256, then the default is 8-bit characters.
X
X     -C[efmF]
X          controls the degree of table compression.
X
X          -Ce directs  flex  to  construct  equivalence  classes,
X          i.e.,  sets  of characters which have identical lexical
X          properties.  Equivalence classes usually give  dramatic
X          reductions  in the final table/object file sizes (typi-
X          cally  a  factor  of  2-5)   and   are   pretty   cheap
X          performance-wise   (one  array  look-up  per  character
X          scanned).
X
X          -Cf specifies that the full scanner  tables  should  be
X          generated - flex should not compress the tables by tak-
X          ing advantages of similar transition functions for dif-
X          ferent states.
X
X          -CF specifies that the alternate fast scanner represen-
X          tation (described in flexdoc(1)) should be used.
X
X          -Cm directs flex to construct meta-equivalence classes,
X          which  are  sets of equivalence classes (or characters,
X          if equivalence classes are not  being  used)  that  are
X          commonly  used  together.  Meta-equivalence classes are
X          often a big win when using compressed tables, but  they
X          have  a  moderate  performance  impact (one or two "if"
X          tests and one array look-up per character scanned).
X
X          A lone -C specifies that the scanner tables  should  be
X          compressed  but  neither  equivalence classes nor meta-
X          equivalence classes should be used.
X
X
X
XVersion 2.3         Last change: 26 May 1990                    3
X
X
X
X
X
X
XFLEX(1)                   USER COMMANDS                   FLEX(1)
X
X
X
X          The options -Cf or  -CF  and  -Cm  do  not  make  sense
X          together - there is no opportunity for meta-equivalence
X          classes if the table is not being  compressed.   Other-
X          wise the options may be freely mixed.
X
X          The default setting is -Cem, which specifies that  flex
X          should   generate   equivalence   classes   and   meta-
X          equivalence classes.  This setting provides the highest
X          degree   of  table  compression.   You  can  trade  off
X          faster-executing scanners at the cost of larger  tables
X          with the following generally being true:
X
X              slowest & smallest
X                    -Cem
X                    -Cm
X                    -Ce
X                    -C
X                    -C{f,F}e
X                    -C{f,F}
X              fastest & largest
X
X
X          -C options are not cumulative;  whenever  the  flag  is
X          encountered, the previous -C settings are forgotten.
X
X     -Sskeleton_file
X          overrides the default skeleton  file  from  which  flex
X          constructs its scanners.  You'll never need this option
X          unless you are doing flex maintenance or development.
X
XSUMMARY OF FLEX REGULAR EXPRESSIONS
X     The patterns in the input are written using an extended  set
X     of regular expressions.  These are:
X
X         x          match the character 'x'
X         .          any character except newline
X         [xyz]      a "character class"; in this case, the pattern
X                      matches either an 'x', a 'y', or a 'z'
X         [abj-oZ]   a "character class" with a range in it; matches
X                      an 'a', a 'b', any letter from 'j' through 'o',
X                      or a 'Z'
X         [^A-Z]     a "negated character class", i.e., any character
X                      but those in the class.  In this case, any
X                      character EXCEPT an uppercase letter.
X         [^A-Z\n]   any character EXCEPT an uppercase letter or
X                      a newline
X         r*         zero or more r's, where r is any regular expression
X         r+         one or more r's
X         r?         zero or one r's (that is, "an optional r")
X         r{2,5}     anywhere from two to five r's
X         r{2,}      two or more r's
X         r{4}       exactly 4 r's
X
X
X
XVersion 2.3         Last change: 26 May 1990                    4
X
X
X
X
X
X
XFLEX(1)                   USER COMMANDS                   FLEX(1)
X
X
X
X         {name}     the expansion of the "name" definition
X                    (see above)
X         "[xyz]\"foo"
X                    the literal string: [xyz]"foo
X         \X         if X is an 'a', 'b', 'f', 'n', 'r', 't', or 'v',
X                      then the ANSI-C interpretation of \x.
X                      Otherwise, a literal 'X' (used to escape
X                      operators such as '*')
X         \123       the character with octal value 123
X         \x2a       the character with hexadecimal value 2a
X         (r)        match an r; parentheses are used to override
X                      precedence (see below)
X
X
X         rs         the regular expression r followed by the
X                      regular expression s; called "concatenation"
X
X
X         r|s        either an r or an s
X
X
X         r/s        an r but only if it is followed by an s.  The
X                      s is not part of the matched text.  This type
X                      of pattern is called as "trailing context".
X         ^r         an r, but only at the beginning of a line
X         r$         an r, but only at the end of a line.  Equivalent
X                      to "r/\n".
X
X
X         <s>r       an r, but only in start condition s (see
X                    below for discussion of start conditions)
X         <s1,s2,s3>r
X                    same, but in any of start conditions s1,
X                    s2, or s3
X
X
X         <<EOF>>    an end-of-file
X         <s1,s2><<EOF>>
X                    an end-of-file when in start condition s1 or s2
X
X     The regular expressions listed above are  grouped  according
X     to  precedence, from highest precedence at the top to lowest
X     at the bottom.   Those  grouped  together  have  equal  pre-
X     cedence.
X
X     Some notes on patterns:
X
X     -    Negated character classes match  newlines  unless  "\n"
X          (or  an equivalent escape sequence) is one of the char-
X          acters explicitly  present  in  the  negated  character
X          class (e.g., "[^A-Z\n]").
X
X
X
X
XVersion 2.3         Last change: 26 May 1990                    5
X
X
X
X
X
X
XFLEX(1)                   USER COMMANDS                   FLEX(1)
X
X
X
X     -    A rule can have at most one instance of  trailing  con-
X          text (the '/' operator or the '$' operator).  The start
X          condition, '^', and "<<EOF>>" patterns can  only  occur
X          at the beginning of a pattern, and, as well as with '/'
X          and '$', cannot be  grouped  inside  parentheses.   The
X          following are all illegal:
X
X              foo/bar$
X              foo|(bar$)
X              foo|^bar
X              <sc1>foo<sc2>bar
X
X
XSUMMARY OF SPECIAL ACTIONS
X     In addition to arbitrary C code, the following can appear in
X     actions:
X
X     -    ECHO copies yytext to the scanner's output.
X
X     -    BEGIN followed by the name of a start condition  places
X          the scanner in the corresponding start condition.
X
X     -    REJECT directs the scanner to proceed on to the "second
X          best"  rule which matched the input (or a prefix of the
X          input).  yytext and yyleng are  set  up  appropriately.
X          Note that REJECT is a particularly expensive feature in
X          terms scanner performance; if it is used in any of  the
X          scanner's   actions  it  will  slow  down  all  of  the
X          scanner's matching.  Furthermore, REJECT cannot be used
X          with the -f or -F options.
X
X          Note also that unlike the other special actions, REJECT
X          is  a  branch;  code  immediately  following  it in the
X          action will not be executed.
X
X     -    yymore() tells  the  scanner  that  the  next  time  it
X          matches  a  rule,  the  corresponding  token  should be
X          appended onto the current value of yytext  rather  than
X          replacing it.
X
X     -    yyless(n) returns all but the first n characters of the
X          current token back to the input stream, where they will
X          be rescanned when the scanner looks for the next match.
X          yytext  and  yyleng  are  adjusted appropriately (e.g.,
X          yyleng will now be equal to n ).
X
X     -    unput(c) puts the  character  c  back  onto  the  input
X          stream.  It will be the next character scanned.
X
X     -    input() reads the next character from the input  stream
X          (this  routine  is  called  yyinput() if the scanner is
X          compiled using C++).
X
X
X
XVersion 2.3         Last change: 26 May 1990                    6
X
X
X
X
X
X
XFLEX(1)                   USER COMMANDS                   FLEX(1)
X
X
X
X     -    yyterminate() can be used in lieu of a return statement
X          in  an action.  It terminates the scanner and returns a
X          0 to the scanner's caller, indicating "all done".
X
X          By default, yyterminate() is also called when  an  end-
X          of-file is encountered.  It is a macro and may be rede-
X          fined.
X
X     -    YY_NEW_FILE is an  action  available  only  in  <<EOF>>
X          rules.   It  means "Okay, I've set up a new input file,
X          continue scanning".
X
X     -    yy_create_buffer( file, size ) takes a FILE pointer and
X          an integer size. It returns a YY_BUFFER_STATE handle to
X          a new input buffer  large  enough  to  accomodate  size
X          characters and associated with the given file.  When in
X          doubt, use YY_BUF_SIZE for the size.
X
X     -    yy_switch_to_buffer(   new_buffer   )   switches    the
X          scanner's  processing to scan for tokens from the given
X          buffer, which must be a YY_BUFFER_STATE.
X
X     -    yy_delete_buffer( buffer ) deletes the given buffer.
X
XVALUES AVAILABLE TO THE USER
X     -    char *yytext holds the text of the current  token.   It
X          may not be modified.
X
X     -    int yyleng holds the length of the current  token.   It
X          may not be modified.
X
X     -    FILE *yyin is the file  which  by  default  flex  reads
X          from.   It  may  be  redefined  but doing so only makes
X          sense before scanning begins.  Changing it in the  mid-
X          dle of scanning will have unexpected results since flex
X          buffers its input.  Once scanning terminates because an
X          end-of-file   has   been  seen,  void  yyrestart(  FILE
X          *new_file ) may be called to  point  yyin  at  the  new
X          input file.
X
X     -    FILE *yyout is the file to which ECHO actions are done.
X          It can be reassigned by the user.
X
X     -    YY_CURRENT_BUFFER returns a YY_BUFFER_STATE  handle  to
X          the current buffer.
X
XMACROS THE USER CAN REDEFINE
X     -    YY_DECL controls how the scanning routine is  declared.
X          By  default, it is "int yylex()", or, if prototypes are
X          being used, "int yylex(void)".  This definition may  be
X          changed  by  redefining the "YY_DECL" macro.  Note that
X          if you give arguments to the scanning routine  using  a
X
X
X
XVersion 2.3         Last change: 26 May 1990                    7
X
X
X
X
X
X
XFLEX(1)                   USER COMMANDS                   FLEX(1)
X
X
X
X          K&R-style/non-prototyped function declaration, you must
X          terminate the definition with a semi-colon (;).
X
X     -    The nature of how the scanner gets  its  input  can  be
X          controlled    by   redefining   the   YY_INPUT   macro.
X          YY_INPUT's         calling         sequence          is
X          "YY_INPUT(buf,result,max_size)".    Its  action  is  to
X          place up to max_size characters in the character  array
X          buf  and  return  in the integer variable result either
X          the number of characters read or the  constant  YY_NULL
X          (0  on  Unix  systems)  to  indicate  EOF.  The default
X          YY_INPUT reads from the global file-pointer "yyin".   A
X          sample  redefinition  of  YY_INPUT  (in the definitions
X          section of the input file):
X
X              %{
X              #undef YY_INPUT
X              #define YY_INPUT(buf,result,max_size) \
X                  { \
X                  int c = getchar(); \
X                  result = (c == EOF) ? YY_NULL : (buf[0] = c, 1); \
X                  }
X              %}
X
X
X     -    When the scanner  receives  an  end-of-file  indication
X          from  YY_INPUT,  it  then checks the yywrap() function.
X          If yywrap() returns false (zero), then  it  is  assumed
X          that  the  function  has  gone ahead and set up yyin to
X          point to another input file,  and  scanning  continues.
X          If  it  returns  true (non-zero), then the scanner ter-
X          minates, returning 0 to its caller.
X
X          The default yywrap() always returns 1.   Presently,  to
X          redefine  it  you  must first "#undef yywrap", as it is
X          currently implemented as a macro.  It  is  likely  that
X          yywrap()  will  soon be defined to be a function rather
X          than a macro.
X
X     -    YY_USER_ACTION can be redefined to  provide  an  action
X          which  is  always  executed prior to the matched rule's
X          action.
X
X     -    The macro YY_USER_INIT may be redefined to  provide  an
X          action which is always executed before the first scan.
X
X     -    In the generated scanner, the actions are all  gathered
X          in  one  large  switch  statement  and  separated using
X          YY_BREAK, which may be redefined.  By  default,  it  is
X          simply  a  "break", to separate each rule's action from
X          the following rule's.
X
X
X
X
XVersion 2.3         Last change: 26 May 1990                    8
X
X
X
X
X
X
XFLEX(1)                   USER COMMANDS                   FLEX(1)
X
X
X
XFILES
X     flex.skel
X          skeleton scanner.
X
X     lex.yy.c
X          generated scanner (called lexyy.c on some systems).
X
X     lex.backtrack
X          backtracking information for -b flag (called lex.bck on
X          some systems).
X
X     -lfl library with which to link the scanners.
X
XSEE ALSO
X     flexdoc(1), lex(1), yacc(1), sed(1), awk(1).
X
X     M. E. Lesk and E. Schmidt, LEX - Lexical Analyzer Generator
X
XDIAGNOSTICS
X     reject_used_but_not_detected undefined or
X
X     yymore_used_but_not_detected undefined -  These  errors  can
X     occur  at compile time.  They indicate that the scanner uses
X     REJECT or yymore() but that flex failed to notice the  fact,
X     meaning that flex scanned the first two sections looking for
X     occurrences of these actions and failed  to  find  any,  but
X     somehow  you  snuck  some in (via a #include file, for exam-
X     ple).  Make an explicit reference to the action in your flex
X     input   file.    (Note  that  previously  flex  supported  a
X     %used/%unused mechanism for dealing with this problem;  this
X     feature  is  still supported but now deprecated, and will go
X     away soon unless the author hears from people who can  argue
X     compellingly that they need it.)
X
X     flex scanner jammed - a scanner compiled with -s has encoun-
X     tered  an  input  string  which wasn't matched by any of its
X     rules.
X
X     flex input buffer overflowed -  a  scanner  rule  matched  a
X     string  long enough to overflow the scanner's internal input
X     buffer  (16K   bytes   -   controlled   by   YY_BUF_MAX   in
X     "flex.skel").
X
X     scanner  requires  -8  flag  -  Your  scanner  specification
X     includes  recognizing  8-bit  characters  and  you  did  not
X     specify the -8 flag (and your site has  not  installed  flex
X     with -8 as the default).
X
X     fatal flex scanner internal error--end of  buffer  missed  -
X     This  can  occur  in  an  scanner which is reentered after a
X     long-jump has jumped out (or over) the scanner's  activation
X     frame.  Before reentering the scanner, use:
X
X
X
XVersion 2.3         Last change: 26 May 1990                    9
X
X
X
X
X
X
XFLEX(1)                   USER COMMANDS                   FLEX(1)
X
X
X
X         yyrestart( yyin );
X
X
X     too many %t classes! - You managed to put every single char-
X     acter  into  its  own %t class.  flex requires that at least
X     one of the classes share characters.
X
XAUTHOR
X     Vern Paxson, with the help of many ideas and  much  inspira-
X     tion from Van Jacobson.  Original version by Jef Poskanzer.
X
X     See flexdoc(1) for additional credits  and  the  address  to
X     send comments to.
X
XDEFICIENCIES / BUGS
X     Some trailing context patterns cannot  be  properly  matched
X     and  generate  warning  messages  ("Dangerous  trailing con-
X     text").  These are patterns where the ending  of  the  first
X     part  of  the rule matches the beginning of the second part,
X     such as "zx*/xy*", where the 'x*' matches  the  'x'  at  the
X     beginning  of  the  trailing  context.  (Note that the POSIX
X     draft states that the text matched by such patterns is unde-
X     fined.)
X
X     For some trailing context rules, parts  which  are  actually
X     fixed-length  are  not  recognized  as  such, leading to the
X     abovementioned performance loss.  In particular, parts using
X     '|'   or  {n}  (such  as  "foo{3}")  are  always  considered
X     variable-length.
X
X     Combining trailing context with the special '|'  action  can
X     result  in fixed trailing context being turned into the more
X     expensive variable trailing context.  For example, this hap-
X     pens in the following example:
X
X         %%
X         abc      |
X         xyz/def
X
X
X     Use of unput() invalidates yytext and yyleng.
X
X     Use of unput() to push back more text than was  matched  can
X     result  in the pushed-back text matching a beginning-of-line
X     ('^') rule even though it didn't come at  the  beginning  of
X     the line (though this is rare!).
X
X     Pattern-matching  of  NUL's  is  substantially  slower  than
X     matching other characters.
X
X     flex does not generate correct  #line  directives  for  code
X     internal to the scanner; thus, bugs in flex.skel yield bogus
X
X
X
XVersion 2.3         Last change: 26 May 1990                   10
X
X
X
X
X
X
XFLEX(1)                   USER COMMANDS                   FLEX(1)
X
X
X
X     line numbers.
X
X     Due to both buffering of input and  read-ahead,  you  cannot
X     intermix  calls to <stdio.h> routines, such as, for example,
X     getchar(), with flex rules and  expect  it  to  work.   Call
X     input() instead.
X
X     The total table entries listed by the -v flag  excludes  the
X     number  of  table  entries needed to determine what rule has
X     been matched.  The number of entries is equal to the  number
X     of  DFA states if the scanner does not use REJECT, and some-
X     what greater than the number of states if it does.
X
X     REJECT cannot be used with the -f or -F options.
X
X     Some of the macros, such as  yywrap(),  may  in  the  future
X     become  functions which live in the -lfl library.  This will
X     doubtless break a lot of  code,  but  may  be  required  for
X     POSIX-compliance.
X
X     The flex internal algorithms need documentation.
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
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X
X
X
X
X
X
X
X
XVersion 2.3         Last change: 26 May 1990                   11
X
X
X
END_OF_FILE
if test 25372 -ne `wc -c <'flex.Doc'`; then
    echo shar: \"'flex.Doc'\" unpacked with wrong size!
fi
# end of 'flex.Doc'
fi
echo shar: End of archive 5 \(of 13\).
cp /dev/null ark5isdone
MISSING=""
for I in 1 2 3 4 5 6 7 8 9 10 11 12 13 ; do
    if test ! -f ark${I}isdone ; then
    MISSING="${MISSING} ${I}"
    fi
done
if test "${MISSING}" = "" ; then
    echo You have unpacked all 13 archives.
    rm -f ark[1-9]isdone ark[1-9][0-9]isdone
else
    echo You still need to unpack the following archives:
    echo "        " ${MISSING}
fi
##  End of shell archive.
exit 0
--
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