Tcl 8.3 upgradeTCL_8_3

1 files changed, 2175 insertions, 0 deletions

diff --git a/tcl/generic/regcomp.c b/tcl/generic/regcomp.c
new file mode 100644
index 00000000000..4aba629f1ec
--- /dev/null
+++ b/tcl/generic/regcomp.c
@@ -0,0 +1,2175 @@
+/*
+ * re_*comp and friends - compile REs
+ * This file #includes several others (see the bottom).
+ *
+ * Copyright (c) 1998, 1999 Henry Spencer.  All rights reserved.
+ * 
+ * Development of this software was funded, in part, by Cray Research Inc.,
+ * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
+ * Corporation, none of whom are responsible for the results.  The author
+ * thanks all of them. 
+ * 
+ * Redistribution and use in source and binary forms -- with or without
+ * modification -- are permitted for any purpose, provided that
+ * redistributions in source form retain this entire copyright notice and
+ * indicate the origin and nature of any modifications.
+ * 
+ * I'd appreciate being given credit for this package in the documentation
+ * of software which uses it, but that is not a requirement.
+ * 
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+ * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "regguts.h"
+
+/*
+ * forward declarations, up here so forward datatypes etc. are defined early
+ */
+/* =====^!^===== begin forwards =====^!^===== */
+/* automatically gathered by fwd; do not hand-edit */
+/* === regcomp.c === */
+int compile _ANSI_ARGS_((regex_t *, CONST chr *, size_t, int));
+static VOID moresubs _ANSI_ARGS_((struct vars *, int));
+static int freev _ANSI_ARGS_((struct vars *, int));
+static VOID makesearch _ANSI_ARGS_((struct vars *, struct nfa *));
+static struct subre *parse _ANSI_ARGS_((struct vars *, int, int, struct state *, struct state *));
+static struct subre *parsebranch _ANSI_ARGS_((struct vars *, int, int, struct state *, struct state *, int));
+static VOID parseqatom _ANSI_ARGS_((struct vars *, int, int, struct state *, struct state *, struct subre *));
+static VOID nonword _ANSI_ARGS_((struct vars *, int, struct state *, struct state *));
+static VOID word _ANSI_ARGS_((struct vars *, int, struct state *, struct state *));
+static int scannum _ANSI_ARGS_((struct vars *));
+static VOID repeat _ANSI_ARGS_((struct vars *, struct state *, struct state *, int, int));
+static VOID bracket _ANSI_ARGS_((struct vars *, struct state *, struct state *));
+static VOID cbracket _ANSI_ARGS_((struct vars *, struct state *, struct state *));
+static VOID brackpart _ANSI_ARGS_((struct vars *, struct state *, struct state *));
+static chr *scanplain _ANSI_ARGS_((struct vars *));
+static VOID leaders _ANSI_ARGS_((struct vars *, struct cvec *));
+static VOID onechr _ANSI_ARGS_((struct vars *, pchr, struct state *, struct state *));
+static VOID dovec _ANSI_ARGS_((struct vars *, struct cvec *, struct state *, struct state *));
+static celt nextleader _ANSI_ARGS_((struct vars *, pchr, pchr));
+static VOID wordchrs _ANSI_ARGS_((struct vars *));
+static struct subre *subre _ANSI_ARGS_((struct vars *, int, int, struct state *, struct state *));
+static VOID freesubre _ANSI_ARGS_((struct vars *, struct subre *));
+static VOID freesrnode _ANSI_ARGS_((struct vars *, struct subre *));
+static VOID optst _ANSI_ARGS_((struct vars *, struct subre *));
+static int numst _ANSI_ARGS_((struct subre *, int));
+static VOID markst _ANSI_ARGS_((struct subre *));
+static VOID cleanst _ANSI_ARGS_((struct vars *));
+static long nfatree _ANSI_ARGS_((struct vars *, struct subre *, FILE *));
+static long nfanode _ANSI_ARGS_((struct vars *, struct subre *, FILE *));
+static int newlacon _ANSI_ARGS_((struct vars *, struct state *, struct state *, int));
+static VOID freelacons _ANSI_ARGS_((struct subre *, int));
+static VOID rfree _ANSI_ARGS_((regex_t *));
+static VOID dump _ANSI_ARGS_((regex_t *, FILE *));
+static VOID dumpst _ANSI_ARGS_((struct subre *, FILE *, int));
+static VOID stdump _ANSI_ARGS_((struct subre *, FILE *, int));
+static char *stid _ANSI_ARGS_((struct subre *, char *, size_t));
+/* === regc_lex.c === */
+static VOID lexstart _ANSI_ARGS_((struct vars *));
+static VOID prefixes _ANSI_ARGS_((struct vars *));
+static VOID lexnest _ANSI_ARGS_((struct vars *, chr *, chr *));
+static VOID lexword _ANSI_ARGS_((struct vars *));
+static int next _ANSI_ARGS_((struct vars *));
+static int lexescape _ANSI_ARGS_((struct vars *));
+static chr lexdigits _ANSI_ARGS_((struct vars *, int, int, int));
+static int brenext _ANSI_ARGS_((struct vars *, pchr));
+static VOID skip _ANSI_ARGS_((struct vars *));
+static chr newline _ANSI_ARGS_((NOPARMS));
+#ifdef REG_DEBUG
+static chr *ch _ANSI_ARGS_((NOPARMS));
+#endif
+static chr chrnamed _ANSI_ARGS_((struct vars *, chr *, chr *, pchr));
+/* === regc_color.c === */
+static VOID initcm _ANSI_ARGS_((struct vars *, struct colormap *));
+static VOID freecm _ANSI_ARGS_((struct colormap *));
+static VOID cmtreefree _ANSI_ARGS_((struct colormap *, union tree *, int));
+static color setcolor _ANSI_ARGS_((struct colormap *, pchr, pcolor));
+static color maxcolor _ANSI_ARGS_((struct colormap *));
+static color newcolor _ANSI_ARGS_((struct colormap *));
+static VOID freecolor _ANSI_ARGS_((struct colormap *, pcolor));
+static color pseudocolor _ANSI_ARGS_((struct colormap *));
+static color subcolor _ANSI_ARGS_((struct colormap *, pchr c));
+static color newsub _ANSI_ARGS_((struct colormap *, pcolor));
+static VOID subrange _ANSI_ARGS_((struct vars *, pchr, pchr, struct state *, struct state *));
+static VOID subblock _ANSI_ARGS_((struct vars *, pchr, struct state *, struct state *));
+static VOID okcolors _ANSI_ARGS_((struct nfa *, struct colormap *));
+static VOID colorchain _ANSI_ARGS_((struct colormap *, struct arc *));
+static VOID uncolorchain _ANSI_ARGS_((struct colormap *, struct arc *));
+static int singleton _ANSI_ARGS_((struct colormap *, pchr c));
+static VOID rainbow _ANSI_ARGS_((struct nfa *, struct colormap *, int, pcolor, struct state *, struct state *));
+static VOID colorcomplement _ANSI_ARGS_((struct nfa *, struct colormap *, int, struct state *, struct state *, struct state *));
+#ifdef REG_DEBUG
+static VOID dumpcolors _ANSI_ARGS_((struct colormap *, FILE *));
+static VOID fillcheck _ANSI_ARGS_((struct colormap *, union tree *, int, FILE *));
+static VOID dumpchr _ANSI_ARGS_((pchr, FILE *));
+#endif
+/* === regc_nfa.c === */
+static struct nfa *newnfa _ANSI_ARGS_((struct vars *, struct colormap *, struct nfa *));
+static VOID freenfa _ANSI_ARGS_((struct nfa *));
+static struct state *newstate _ANSI_ARGS_((struct nfa *));
+static struct state *newfstate _ANSI_ARGS_((struct nfa *, int flag));
+static VOID dropstate _ANSI_ARGS_((struct nfa *, struct state *));
+static VOID freestate _ANSI_ARGS_((struct nfa *, struct state *));
+static VOID destroystate _ANSI_ARGS_((struct nfa *, struct state *));
+static VOID newarc _ANSI_ARGS_((struct nfa *, int, pcolor, struct state *, struct state *));
+static struct arc *allocarc _ANSI_ARGS_((struct nfa *, struct state *));
+static VOID freearc _ANSI_ARGS_((struct nfa *, struct arc *));
+static struct arc *findarc _ANSI_ARGS_((struct state *, int, pcolor));
+static VOID cparc _ANSI_ARGS_((struct nfa *, struct arc *, struct state *, struct state *));
+static VOID moveins _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
+static VOID copyins _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
+static VOID moveouts _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
+static VOID copyouts _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
+static VOID cloneouts _ANSI_ARGS_((struct nfa *, struct state *, struct state *, struct state *, int));
+static VOID delsub _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
+static VOID deltraverse _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
+static VOID dupnfa _ANSI_ARGS_((struct nfa *, struct state *, struct state *, struct state *, struct state *));
+static VOID duptraverse _ANSI_ARGS_((struct nfa *, struct state *, struct state *));
+static VOID cleartraverse _ANSI_ARGS_((struct nfa *, struct state *));
+static VOID specialcolors _ANSI_ARGS_((struct nfa *));
+static long optimize _ANSI_ARGS_((struct nfa *, FILE *));
+static VOID pullback _ANSI_ARGS_((struct nfa *, FILE *));
+static int pull _ANSI_ARGS_((struct nfa *, struct arc *));
+static VOID pushfwd _ANSI_ARGS_((struct nfa *, FILE *));
+static int push _ANSI_ARGS_((struct nfa *, struct arc *));
+#define	INCOMPATIBLE	1	/* destroys arc */
+#define	SATISFIED	2	/* constraint satisfied */
+#define	COMPATIBLE	3	/* compatible but not satisfied yet */
+static int combine _ANSI_ARGS_((struct arc *, struct arc *));
+static VOID fixempties _ANSI_ARGS_((struct nfa *, FILE *));
+static int unempty _ANSI_ARGS_((struct nfa *, struct arc *));
+static VOID cleanup _ANSI_ARGS_((struct nfa *));
+static VOID markreachable _ANSI_ARGS_((struct nfa *, struct state *, struct state *, struct state *));
+static VOID markcanreach _ANSI_ARGS_((struct nfa *, struct state *, struct state *, struct state *));
+static long analyze _ANSI_ARGS_((struct nfa *));
+static VOID compact _ANSI_ARGS_((struct nfa *, struct cnfa *));
+static VOID carcsort _ANSI_ARGS_((struct carc *, struct carc *));
+static VOID freecnfa _ANSI_ARGS_((struct cnfa *));
+static VOID dumpnfa _ANSI_ARGS_((struct nfa *, FILE *));
+#ifdef REG_DEBUG
+static VOID dumpstate _ANSI_ARGS_((struct state *, FILE *));
+static VOID dumparcs _ANSI_ARGS_((struct state *, FILE *));
+static int dumprarcs _ANSI_ARGS_((struct arc *, struct state *, FILE *, int));
+static VOID dumparc _ANSI_ARGS_((struct arc *, struct state *, FILE *));
+#endif
+static VOID dumpcnfa _ANSI_ARGS_((struct cnfa *, FILE *));
+#ifdef REG_DEBUG
+static VOID dumpcstate _ANSI_ARGS_((int, struct carc *, struct cnfa *, FILE *));
+#endif
+/* === regc_cvec.c === */
+static struct cvec *newcvec _ANSI_ARGS_((int, int, int));
+static struct cvec *clearcvec _ANSI_ARGS_((struct cvec *));
+static VOID addchr _ANSI_ARGS_((struct cvec *, pchr));
+static VOID addrange _ANSI_ARGS_((struct cvec *, pchr, pchr));
+static VOID addmcce _ANSI_ARGS_((struct cvec *, chr *, chr *));
+static int haschr _ANSI_ARGS_((struct cvec *, pchr));
+static struct cvec *getcvec _ANSI_ARGS_((struct vars *, int, int, int));
+static VOID freecvec _ANSI_ARGS_((struct cvec *));
+/* === regc_locale.c === */
+static int nmcces _ANSI_ARGS_((struct vars *));
+static int nleaders _ANSI_ARGS_((struct vars *));
+static struct cvec *allmcces _ANSI_ARGS_((struct vars *, struct cvec *));
+static celt element _ANSI_ARGS_((struct vars *, chr *, chr *));
+static struct cvec *range _ANSI_ARGS_((struct vars *, celt, celt, int));
+static int before _ANSI_ARGS_((celt, celt));
+static struct cvec *eclass _ANSI_ARGS_((struct vars *, celt, int));
+static struct cvec *cclass _ANSI_ARGS_((struct vars *, chr *, chr *, int));
+static struct cvec *allcases _ANSI_ARGS_((struct vars *, pchr));
+static int cmp _ANSI_ARGS_((CONST chr *, CONST chr *, size_t));
+static int casecmp _ANSI_ARGS_((CONST chr *, CONST chr *, size_t));
+/* automatically gathered by fwd; do not hand-edit */
+/* =====^!^===== end forwards =====^!^===== */
+
+
+
+/* internal variables, bundled for easy passing around */
+struct vars {
+	regex_t *re;
+	chr *now;		/* scan pointer into string */
+	chr *stop;		/* end of string */
+	chr *savenow;		/* saved now and stop for "subroutine call" */
+	chr *savestop;
+	int err;		/* error code (0 if none) */
+	int cflags;		/* copy of compile flags */
+	int lasttype;		/* type of previous token */
+	int nexttype;		/* type of next token */
+	chr nextvalue;		/* value (if any) of next token */
+	int lexcon;		/* lexical context type (see lex.c) */
+	int nsubexp;		/* subexpression count */
+	struct subre **subs;	/* subRE pointer vector */
+	size_t nsubs;		/* length of vector */
+	struct subre *sub10[10];	/* initial vector, enough for most */
+	struct nfa *nfa;	/* the NFA */
+	struct colormap *cm;	/* character color map */
+	color nlcolor;		/* color of newline */
+	struct state *wordchrs;	/* state in nfa holding word-char outarcs */
+	struct subre *tree;	/* subexpression tree */
+	struct subre *treechain;	/* all tree nodes allocated */
+	struct subre *treefree;		/* any free tree nodes */
+	int ntree;		/* number of tree nodes */
+	struct cvec *cv;	/* interface cvec */
+	struct cvec *cv2;	/* utility cvec */
+	struct cvec *mcces;	/* collating-element information */
+#		define	ISCELEADER(v,c)	(v->mcces != NULL && haschr(v->mcces, (c)))
+	struct state *mccepbegin;	/* in nfa, start of MCCE prototypes */
+	struct state *mccepend;	/* in nfa, end of MCCE prototypes */
+	struct subre *lacons;	/* lookahead-constraint vector */
+	int nlacons;		/* size of lacons */
+};
+
+/* parsing macros; most know that `v' is the struct vars pointer */
+#define	NEXT()	(next(v))		/* advance by one token */
+#define	SEE(t)	(v->nexttype == (t))	/* is next token this? */
+#define	EAT(t)	(SEE(t) && next(v))	/* if next is this, swallow it */
+#define	VISERR(vv)	((vv)->err != 0)	/* have we seen an error yet? */
+#define	ISERR()	VISERR(v)
+#define	VERR(vv,e)	((vv)->nexttype = EOS, ((vv)->err) ? (vv)->err :\
+							((vv)->err = (e)))
+#define	ERR(e)	VERR(v, e)		/* record an error */
+#define	NOERR()	{if (ISERR()) return;}	/* if error seen, return */
+#define	NOERRN()	{if (ISERR()) return NULL;}	/* NOERR with retval */
+#define	NOERRZ()	{if (ISERR()) return 0;}	/* NOERR with retval */
+#define	INSIST(c, e)	((c) ? 0 : ERR(e))	/* if condition false, error */
+#define	NOTE(b)	(v->re->re_info |= (b))		/* note visible condition */
+#define	EMPTYARC(x, y)	newarc(v->nfa, EMPTY, 0, x, y)
+
+/* token type codes, some also used as NFA arc types */
+#define	EMPTY	'n'		/* no token present */
+#define	EOS	'e'		/* end of string */
+#define	PLAIN	'p'		/* ordinary character */
+#define	DIGIT	'd'		/* digit (in bound) */
+#define	BACKREF	'b'		/* back reference */
+#define	COLLEL	'I'		/* start of [. */
+#define	ECLASS	'E'		/* start of [= */
+#define	CCLASS	'C'		/* start of [: */
+#define	END	'X'		/* end of [. [= [: */
+#define	RANGE	'R'		/* - within [] which might be range delim. */
+#define	LACON	'L'		/* lookahead constraint subRE */
+#define	AHEAD	'a'		/* color-lookahead arc */
+#define	BEHIND	'r'		/* color-lookbehind arc */
+#define	WBDRY	'w'		/* word boundary constraint */
+#define	NWBDRY	'W'		/* non-word-boundary constraint */
+#define	SBEGIN	'A'		/* beginning of string (even if not BOL) */
+#define	SEND	'Z'		/* end of string (even if not EOL) */
+#define	PREFER	'P'		/* length preference */
+
+/* is an arc colored, and hence on a color chain? */
+#define	COLORED(a)	((a)->type == PLAIN || (a)->type == AHEAD || \
+							(a)->type == BEHIND)
+
+
+
+/* static function list */
+static struct fns functions = {
+	rfree,			/* regfree insides */
+};
+
+
+
+/*
+ - compile - compile regular expression
+ ^ int compile(regex_t *, CONST chr *, size_t, int);
+ */
+int
+compile(re, string, len, flags)
+regex_t *re;
+CONST chr *string;
+size_t len;
+int flags;
+{
+	struct vars var;
+	struct vars *v = &var;
+	struct guts *g;
+	int i;
+	size_t j;
+	FILE *debug = (flags&REG_PROGRESS) ? stdout : (FILE *)NULL;
+#	define	CNOERR()	{ if (ISERR()) return freev(v, v->err); }
+
+	/* sanity checks */
+
+	if (re == NULL || string == NULL)
+		return REG_INVARG;
+	if ((flags&REG_QUOTE) &&
+			(flags&(REG_ADVANCED|REG_EXPANDED|REG_NEWLINE)))
+		return REG_INVARG;
+	if (!(flags&REG_EXTENDED) && (flags&REG_ADVF))
+		return REG_INVARG;
+
+	/* initial setup (after which freev() is callable) */
+	v->re = re;
+	v->now = (chr *)string;
+	v->stop = v->now + len;
+	v->savenow = v->savestop = NULL;
+	v->err = 0;
+	v->cflags = flags;
+	v->nsubexp = 0;
+	v->subs = v->sub10;
+	v->nsubs = 10;
+	for (j = 0; j < v->nsubs; j++)
+		v->subs[j] = NULL;
+	v->nfa = NULL;
+	v->cm = NULL;
+	v->nlcolor = COLORLESS;
+	v->wordchrs = NULL;
+	v->tree = NULL;
+	v->treechain = NULL;
+	v->treefree = NULL;
+	v->cv = NULL;
+	v->cv2 = NULL;
+	v->mcces = NULL;
+	v->lacons = NULL;
+	v->nlacons = 0;
+	re->re_magic = REMAGIC;
+	re->re_info = 0;		/* bits get set during parse */
+	re->re_csize = sizeof(chr);
+	re->re_guts = NULL;
+	re->re_fns = VS(&functions);
+
+	/* more complex setup, malloced things */
+	re->re_guts = VS(MALLOC(sizeof(struct guts)));
+	if (re->re_guts == NULL)
+		return freev(v, REG_ESPACE);
+	g = (struct guts *)re->re_guts;
+	g->tree = NULL;
+	initcm(v, &g->cmap);
+	v->cm = &g->cmap;
+	g->lacons = NULL;
+	g->nlacons = 0;
+	ZAPCNFA(g->search);
+	v->nfa = newnfa(v, v->cm, (struct nfa *)NULL);
+	CNOERR();
+	v->cv = newcvec(100, 20, 10);
+	if (v->cv == NULL)
+		return freev(v, REG_ESPACE);
+	i = nmcces(v);
+	if (i > 0) {
+		v->mcces = newcvec(nleaders(v), 0, i);
+		CNOERR();
+		v->mcces = allmcces(v, v->mcces);
+		leaders(v, v->mcces);
+		addmcce(v->mcces, (chr *)NULL, (chr *)NULL);	/* dummy */
+	}
+	CNOERR();
+
+	/* parsing */
+	lexstart(v);			/* also handles prefixes */
+	if ((v->cflags&REG_NLSTOP) || (v->cflags&REG_NLANCH)) {
+		/* assign newline a unique color */
+		v->nlcolor = subcolor(v->cm, newline());
+		okcolors(v->nfa, v->cm);
+	}
+	CNOERR();
+	v->tree = parse(v, EOS, PLAIN, v->nfa->init, v->nfa->final);
+	assert(SEE(EOS));		/* even if error; ISERR() => SEE(EOS) */
+	CNOERR();
+	assert(v->tree != NULL);
+
+	/* finish setup of nfa and its subre tree */
+	specialcolors(v->nfa);
+	CNOERR();
+	if (debug != NULL) {
+		fprintf(debug, "\n\n\n========= RAW ==========\n");
+		dumpnfa(v->nfa, debug);
+		dumpst(v->tree, debug, 1);
+	}
+	optst(v, v->tree);
+	v->ntree = numst(v->tree, 1);
+	markst(v->tree);
+	cleanst(v);
+	if (debug != NULL) {
+		fprintf(debug, "\n\n\n========= TREE FIXED ==========\n");
+		dumpst(v->tree, debug, 1);
+	}
+
+	/* build compacted NFAs for tree and lacons */
+	re->re_info |= nfatree(v, v->tree, debug);
+	CNOERR();
+	assert(v->nlacons == 0 || v->lacons != NULL);
+	for (i = 1; i < v->nlacons; i++) {
+		if (debug != NULL)
+			fprintf(debug, "\n\n\n========= LA%d ==========\n", i);
+		nfanode(v, &v->lacons[i], debug);
+	}
+	CNOERR();
+	if (v->tree->flags&SHORTER)
+		NOTE(REG_USHORTEST);
+
+	/* build compacted NFAs for tree, lacons, fast search */
+	if (debug != NULL)
+		fprintf(debug, "\n\n\n========= SEARCH ==========\n");
+	/* can sacrifice main NFA now, so use it as work area */
+	(DISCARD)optimize(v->nfa, debug);
+	CNOERR();
+	makesearch(v, v->nfa);
+	CNOERR();
+	compact(v->nfa, &g->search);
+	CNOERR();
+
+	/* looks okay, package it up */
+	re->re_nsub = v->nsubexp;
+	v->re = NULL;			/* freev no longer frees re */
+	g->magic = GUTSMAGIC;
+	g->cflags = v->cflags;
+	g->info = re->re_info;
+	g->nsub = re->re_nsub;
+	g->tree = v->tree;
+	v->tree = NULL;
+	g->ntree = v->ntree;
+	g->compare = (v->cflags&REG_ICASE) ? casecmp : cmp;
+	g->lacons = v->lacons;
+	v->lacons = NULL;
+	g->nlacons = v->nlacons;
+
+	if (flags&REG_DUMP)
+		dump(re, stdout);
+
+	assert(v->err == 0);
+	return freev(v, 0);
+}
+
+/*
+ - moresubs - enlarge subRE vector
+ ^ static VOID moresubs(struct vars *, int);
+ */
+static VOID
+moresubs(v, wanted)
+struct vars *v;
+int wanted;			/* want enough room for this one */
+{
+	struct subre **p;
+	size_t n;
+
+	assert(wanted > 0 && (size_t)wanted >= v->nsubs);
+	n = (size_t)wanted * 3 / 2 + 1;
+	if (v->subs == v->sub10) {
+		p = (struct subre **)MALLOC(n * sizeof(struct subre *));
+		if (p != NULL)
+			memcpy(VS(p), VS(v->subs),
+					v->nsubs * sizeof(struct subre *));
+	} else
+		p = (struct subre **)REALLOC(v->subs, n*sizeof(struct subre *));
+	if (p == NULL) {
+		ERR(REG_ESPACE);
+		return;
+	}
+	v->subs = p;
+	for (p = &v->subs[v->nsubs]; v->nsubs < n; p++, v->nsubs++)
+		*p = NULL;
+	assert(v->nsubs == n);
+	assert((size_t)wanted < v->nsubs);
+}
+
+/*
+ - freev - free vars struct's substructures where necessary
+ * Optionally does error-number setting, and always returns error code
+ * (if any), to make error-handling code terser.
+ ^ static int freev(struct vars *, int);
+ */
+static int
+freev(v, err)
+struct vars *v;
+int err;
+{
+	if (v->re != NULL)
+		rfree(v->re);
+	if (v->subs != v->sub10)
+		FREE(v->subs);
+	if (v->nfa != NULL)
+		freenfa(v->nfa);
+	if (v->tree != NULL)
+		freesubre(v, v->tree);
+	if (v->treechain != NULL)
+		cleanst(v);
+	if (v->cv != NULL)
+		freecvec(v->cv);
+	if (v->cv2 != NULL)
+		freecvec(v->cv2);
+	if (v->mcces != NULL)
+		freecvec(v->mcces);
+	if (v->lacons != NULL)
+		freelacons(v->lacons, v->nlacons);
+	ERR(err);			/* nop if err==0 */
+
+	return v->err;
+}
+
+/*
+ - makesearch - turn an NFA into a search NFA (implicit prepend of .*?)
+ * NFA must have been optimize()d already.
+ ^ static VOID makesearch(struct vars *, struct nfa *);
+ */
+static VOID
+makesearch(v, nfa)
+struct vars *v;
+struct nfa *nfa;
+{
+	struct arc *a;
+	struct arc *b;
+	struct state *pre = nfa->pre;
+	struct state *s;
+	struct state *s2;
+	struct state *slist;
+
+	/* no loops are needed if it's anchored */
+	for (a = pre->outs; a != NULL; a = a->outchain) {
+		assert(a->type == PLAIN);
+		if (a->co != nfa->bos[0] && a->co != nfa->bos[1])
+			break;
+	}
+	if (a != NULL) {
+		/* add implicit .* in front */
+		rainbow(nfa, v->cm, PLAIN, COLORLESS, pre, pre);
+
+		/* and ^* and \A* too -- not always necessary, but harmless */
+		newarc(nfa, PLAIN, nfa->bos[0], pre, pre);
+		newarc(nfa, PLAIN, nfa->bos[1], pre, pre);
+	}
+
+	/*
+	 * Now here's the subtle part.  Because many REs have no lookback
+	 * constraints, often knowing when you were in the pre state tells
+	 * you little; it's the next state(s) that are informative.  But
+	 * some of them may have other inarcs, i.e. it may be possible to
+	 * make actual progress and then return to one of them.  We must
+	 * de-optimize such cases, splitting each such state into progress
+	 * and no-progress states.
+	 */
+
+	/* first, make a list of the states */
+	slist = NULL;
+	for (a = pre->outs; a != NULL; a = a->outchain) {
+		s = a->to;
+		for (b = s->ins; b != NULL; b = b->inchain)
+			if (b->from != pre)
+				break;
+		if (b != NULL) {		/* must be split */
+			s->tmp = slist;
+			slist = s;
+		}
+	}
+
+	/* do the splits */
+	for (s = slist; s != NULL; s = s2) {
+		s2 = newstate(nfa);
+		copyouts(nfa, s, s2);
+		for (a = s->ins; a != NULL; a = b) {
+			b = a->inchain;
+			if (a->from != pre) {
+				cparc(nfa, a, a->from, s2);
+				freearc(nfa, a);
+			}
+		}
+		s2 = s->tmp;
+		s->tmp = NULL;		/* clean up while we're at it */
+	}
+}
+
+/*
+ - parse - parse an RE
+ * This is actually just the top level, which parses a bunch of branches
+ * tied together with '|'.  They appear in the tree as the left children
+ * of a chain of '|' subres.
+ ^ static struct subre *parse(struct vars *, int, int, struct state *,
+ ^ 	struct state *);
+ */
+static struct subre *
+parse(v, stopper, type, init, final)
+struct vars *v;
+int stopper;			/* EOS or ')' */
+int type;			/* LACON (lookahead subRE) or PLAIN */
+struct state *init;		/* initial state */
+struct state *final;		/* final state */
+{
+	struct state *left;	/* scaffolding for branch */
+	struct state *right;
+	struct subre *branches;	/* top level */
+	struct subre *branch;	/* current branch */
+	struct subre *t;	/* temporary */
+	int firstbranch;	/* is this the first branch? */
+
+	assert(stopper == ')' || stopper == EOS);
+
+	branches = subre(v, '|', LONGER, init, final);
+	NOERRN();
+	branch = branches;
+	firstbranch = 1;
+	do {	/* a branch */
+		if (!firstbranch) {
+			/* need a place to hang it */
+			branch->right = subre(v, '|', LONGER, init, final);
+			NOERRN();
+			branch = branch->right;
+		}
+		firstbranch = 0;
+		left = newstate(v->nfa);
+		right = newstate(v->nfa);
+		NOERRN();
+		EMPTYARC(init, left);
+		EMPTYARC(right, final);
+		NOERRN();
+		branch->left = parsebranch(v, stopper, type, left, right, 0);
+		NOERRN();
+		branch->flags |= UP(branch->flags | branch->left->flags);
+		if ((branch->flags &~ branches->flags) != 0)	/* new flags */
+			for (t = branches; t != branch; t = t->right)
+				t->flags |= branch->flags;
+	} while (EAT('|'));
+	assert(SEE(stopper) || SEE(EOS));
+
+	if (!SEE(stopper)) {
+		assert(stopper == ')' && SEE(EOS));
+		ERR(REG_EPAREN);
+	}
+
+	/* optimize out simple cases */
+	if (branch == branches) {	/* only one branch */
+		assert(branch->right == NULL);
+		t = branch->left;
+		branch->left = NULL;
+		freesubre(v, branches);
+		branches = t;
+	} else if (!MESSY(branches->flags)) {	/* no interesting innards */
+		freesubre(v, branches->left);
+		branches->left = NULL;
+		freesubre(v, branches->right);
+		branches->right = NULL;
+		branches->op = '=';
+	}
+
+	return branches;
+}
+
+/*
+ - parsebranch - parse one branch of an RE
+ * This mostly manages concatenation, working closely with parseqatom().
+ * Concatenated things are bundled up as much as possible, with separate
+ * ',' nodes introduced only when necessary due to substructure.
+ ^ static struct subre *parsebranch(struct vars *, int, int, struct state *,
+ ^ 	struct state *, int);
+ */
+static struct subre *
+parsebranch(v, stopper, type, left, right, partial)
+struct vars *v;
+int stopper;			/* EOS or ')' */
+int type;			/* LACON (lookahead subRE) or PLAIN */
+struct state *left;		/* leftmost state */
+struct state *right;		/* rightmost state */
+int partial;			/* is this only part of a branch? */
+{
+	struct state *lp;	/* left end of current construct */
+	int seencontent;	/* is there anything in this branch yet? */
+	struct subre *t;
+
+	lp = left;
+	seencontent = 0;
+	t = subre(v, '=', 0, left, right);	/* op '=' is tentative */
+	NOERRN();
+	while (!SEE('|') && !SEE(stopper) && !SEE(EOS)) {
+		if (seencontent) {	/* implicit concat operator */
+			lp = newstate(v->nfa);
+			NOERRN();
+			moveins(v->nfa, right, lp);
+		}
+		seencontent = 1;
+
+		/* NB, recursion in parseqatom() may swallow rest of branch */
+		parseqatom(v, stopper, type, lp, right, t);
+	}
+
+	if (!seencontent) {		/* empty branch */
+		if (!partial)
+			NOTE(REG_UUNSPEC);
+		assert(lp == left);
+		EMPTYARC(left, right);
+	}
+
+	return t;
+}
+
+/*
+ - parseqatom - parse one quantified atom or constraint of an RE
+ * The bookkeeping near the end cooperates very closely with parsebranch();
+ * in particular, it contains a recursion that can involve parsing the rest
+ * of the branch, making this function's name somewhat inaccurate.
+ ^ static VOID parseqatom(struct vars *, int, int, struct state *,
+ ^ 	struct state *, struct subre *);
+ */
+static VOID
+parseqatom(v, stopper, type, lp, rp, top)
+struct vars *v;
+int stopper;			/* EOS or ')' */
+int type;			/* LACON (lookahead subRE) or PLAIN */
+struct state *lp;		/* left state to hang it on */
+struct state *rp;		/* right state to hang it on */
+struct subre *top;		/* subtree top */
+{
+	struct state *s;	/* temporaries for new states */
+	struct state *s2;
+#	define	ARCV(t, val)	newarc(v->nfa, t, val, lp, rp)
+	int m, n;
+	struct subre *atom;	/* atom's subtree */
+	struct subre *t;
+	int cap;		/* capturing parens? */
+	int pos;		/* positive lookahead? */
+	int subno;		/* capturing-parens or backref number */
+	int atomtype;
+	int qprefer;		/* quantifier short/long preference */
+	int f;
+	struct subre **atomp;	/* where the pointer to atom is */
+
+	/* initial bookkeeping */
+	atom = NULL;
+	assert(lp->nouts == 0);	/* must string new code */
+	assert(rp->nins == 0);	/*  between lp and rp */
+	subno = 0;		/* just to shut lint up */
+
+	/* an atom or constraint... */
+	atomtype = v->nexttype;
+	switch (atomtype) {
+	/* first, constraints, which end by returning */
+	case '^':
+		ARCV('^', 1);
+		if (v->cflags&REG_NLANCH)
+			ARCV(BEHIND, v->nlcolor);
+		NEXT();
+		return;
+		break;
+	case '$':
+		ARCV('$', 1);
+		if (v->cflags&REG_NLANCH)
+			ARCV(AHEAD, v->nlcolor);
+		NEXT();
+		return;
+		break;
+	case SBEGIN:
+		ARCV('^', 1);	/* BOL */
+		ARCV('^', 0);	/* or BOS */
+		NEXT();
+		return;
+		break;
+	case SEND:
+		ARCV('$', 1);	/* EOL */
+		ARCV('$', 0);	/* or EOS */
+		NEXT();
+		return;
+		break;
+	case '<':
+		wordchrs(v);	/* does NEXT() */
+		s = newstate(v->nfa);
+		NOERR();
+		nonword(v, BEHIND, lp, s);
+		word(v, AHEAD, s, rp);
+		return;
+		break;
+	case '>':
+		wordchrs(v);	/* does NEXT() */
+		s = newstate(v->nfa);
+		NOERR();
+		word(v, BEHIND, lp, s);
+		nonword(v, AHEAD, s, rp);
+		return;
+		break;
+	case WBDRY:
+		wordchrs(v);	/* does NEXT() */
+		s = newstate(v->nfa);
+		NOERR();
+		nonword(v, BEHIND, lp, s);
+		word(v, AHEAD, s, rp);
+		s = newstate(v->nfa);
+		NOERR();
+		word(v, BEHIND, lp, s);
+		nonword(v, AHEAD, s, rp);
+		return;
+		break;
+	case NWBDRY:
+		wordchrs(v);	/* does NEXT() */
+		s = newstate(v->nfa);
+		NOERR();
+		word(v, BEHIND, lp, s);
+		word(v, AHEAD, s, rp);
+		s = newstate(v->nfa);
+		NOERR();
+		nonword(v, BEHIND, lp, s);
+		nonword(v, AHEAD, s, rp);
+		return;
+		break;
+	case LACON:	/* lookahead constraint */
+		pos = v->nextvalue;
+		NEXT();
+		s = newstate(v->nfa);
+		s2 = newstate(v->nfa);
+		NOERR();
+		t = parse(v, ')', LACON, s, s2);
+		freesubre(v, t);	/* internal structure irrelevant */
+		assert(SEE(')') || ISERR());
+		NEXT();
+		n = newlacon(v, s, s2, pos);
+		NOERR();
+		ARCV(LACON, n);
+		return;
+		break;
+	/* then errors, to get them out of the way */
+	case '*':
+	case '+':
+	case '?':
+	case '{':
+		ERR(REG_BADRPT);
+		return;
+		break;
+	default:
+		ERR(REG_ASSERT);
+		return;
+		break;
+	/* then plain characters, and minor variants on that theme */
+	case ')':		/* unbalanced paren */
+		if ((v->cflags&REG_ADVANCED) != REG_EXTENDED) {
+			ERR(REG_EPAREN);
+			return;
+		}
+		/* legal in EREs due to specification botch */
+		NOTE(REG_UPBOTCH);
+		/* fallthrough into case PLAIN */
+	case PLAIN:
+		onechr(v, v->nextvalue, lp, rp);
+		okcolors(v->nfa, v->cm);
+		NOERR();
+		NEXT();
+		break;
+	case '[':
+		if (v->nextvalue == 1)
+			bracket(v, lp, rp);
+		else
+			cbracket(v, lp, rp);
+		assert(SEE(']') || ISERR());
+		NEXT();
+		break;
+	case '.':
+		rainbow(v->nfa, v->cm, PLAIN,
+				(v->cflags&REG_NLSTOP) ? v->nlcolor : COLORLESS,
+				lp, rp);
+		NEXT();
+		break;
+	/* and finally the ugly stuff */
+	case '(':	/* value flags as capturing or non */
+		cap = (type == LACON) ? 0 : v->nextvalue;
+		if (cap) {
+			v->nsubexp++;
+			subno = v->nsubexp;
+			if ((size_t)subno >= v->nsubs)
+				moresubs(v, subno);
+			assert((size_t)subno < v->nsubs);
+		} else
+			atomtype = PLAIN;	/* something that's not '(' */
+		NEXT();
+		/* need new endpoints because tree will contain pointers */
+		s = newstate(v->nfa);
+		s2 = newstate(v->nfa);
+		NOERR();
+		EMPTYARC(lp, s);
+		EMPTYARC(s2, rp);
+		NOERR();
+		atom = parse(v, ')', PLAIN, s, s2);
+		assert(SEE(')') || ISERR());
+		NEXT();
+		NOERR();
+		if (cap) {
+			v->subs[subno] = atom;
+			t = subre(v, '(', atom->flags|CAP, lp, rp);
+			NOERR();
+			t->subno = subno;
+			t->left = atom;
+			atom = t;
+		}
+		/* postpone everything else pending possible {0} */
+		break;
+	case BACKREF:	/* the Feature From The Black Lagoon */
+		INSIST(type != LACON, REG_ESUBREG);
+		INSIST(v->nextvalue < v->nsubs, REG_ESUBREG);
+		INSIST(v->subs[v->nextvalue] != NULL, REG_ESUBREG);
+		NOERR();
+		assert(v->nextvalue > 0);
+		atom = subre(v, 'b', BACKR, lp, rp);
+		subno = v->nextvalue;
+		atom->subno = subno;
+		EMPTYARC(lp, rp);	/* temporarily, so there's something */
+		NEXT();
+		break;
+	}
+
+	/* ...and an atom may be followed by a quantifier */
+	switch (v->nexttype) {
+	case '*':
+		m = 0;
+		n = INFINITY;
+		qprefer = (v->nextvalue) ? LONGER : SHORTER;
+		NEXT();
+		break;
+	case '+':
+		m = 1;
+		n = INFINITY;
+		qprefer = (v->nextvalue) ? LONGER : SHORTER;
+		NEXT();
+		break;
+	case '?':
+		m = 0;
+		n = 1;
+		qprefer = (v->nextvalue) ? LONGER : SHORTER;
+		NEXT();
+		break;
+	case '{':
+		NEXT();
+		m = scannum(v);
+		if (EAT(',')) {
+			if (SEE(DIGIT))
+				n = scannum(v);
+			else
+				n = INFINITY;
+			if (m > n) {
+				ERR(REG_BADBR);
+				return;
+			}
+			/* {m,n} exercises preference, even if it's {m,m} */
+			qprefer = (v->nextvalue) ? LONGER : SHORTER;
+		} else {
+			n = m;
+			/* {m} passes operand's preference through */
+			qprefer = 0;
+		}
+		if (!SEE('}')) {	/* catches errors too */
+			ERR(REG_BADBR);
+			return;
+		}
+		NEXT();
+		break;
+	default:		/* no quantifier */
+		m = n = 1;
+		qprefer = 0;
+		break;
+	}
+
+	/* annoying special case:  {0} or {0,0} cancels everything */
+	if (m == 0 && n == 0) {
+		if (atom != NULL)
+			freesubre(v, atom);
+		if (atomtype == '(')
+			v->subs[subno] = NULL;
+		delsub(v->nfa, lp, rp);
+		EMPTYARC(lp, rp);
+		return;
+	}
+
+	/* if not a messy case, avoid hard part */
+	assert(!MESSY(top->flags));
+	f = top->flags | qprefer | ((atom != NULL) ? atom->flags : 0);
+	if (atomtype != '(' && atomtype != BACKREF && !MESSY(UP(f))) {
+		if (!(m == 1 && n == 1))
+			repeat(v, lp, rp, m, n);
+		if (atom != NULL)
+			freesubre(v, atom);
+		top->flags = f;
+		return;
+	}
+
+	/*
+	 * hard part:  something messy
+	 * That is, capturing parens, back reference, short/long clash, or
+	 * an atom with substructure containing one of those.
+	 */
+
+	/* now we'll need a subre for the contents even if they're boring */
+	if (atom == NULL) {
+		atom = subre(v, '=', 0, lp, rp);
+		NOERR();
+	}
+
+	/*
+	 * prepare a general-purpose state skeleton
+	 *
+	 *    ---> [s] ---prefix---> [begin] ---atom---> [end] ----rest---> [rp]
+	 *   /                                            /
+	 * [lp] ----> [s2] ----bypass---------------------
+	 *
+	 * where bypass is an empty, and prefix is some repetitions of atom
+	 */
+	s = newstate(v->nfa);		/* first, new endpoints for the atom */
+	s2 = newstate(v->nfa);
+	NOERR();
+	moveouts(v->nfa, lp, s);
+	moveins(v->nfa, rp, s2);
+	NOERR();
+	atom->begin = s;
+	atom->end = s2;
+	s = newstate(v->nfa);		/* and spots for prefix and bypass */
+	s2 = newstate(v->nfa);
+	NOERR();
+	EMPTYARC(lp, s);
+	EMPTYARC(lp, s2);
+	NOERR();
+
+	/* break remaining subRE into x{...} and what follows */
+	t = subre(v, '.', COMBINE(qprefer, atom->flags), lp, rp);
+	t->left = atom;
+	atomp = &t->left;
+	/* here we should recurse... but we must postpone that to the end */
+
+	/* split top into prefix and remaining */
+	assert(top->op == '=' && top->left == NULL && top->right == NULL);
+	top->left = subre(v, '=', top->flags, top->begin, lp);
+	top->op = '.';
+	top->right = t;
+
+	/* if it's a backref, now is the time to replicate the subNFA */
+	if (atomtype == BACKREF) {
+		assert(atom->begin->nouts == 1);	/* just the EMPTY */
+		delsub(v->nfa, atom->begin, atom->end);
+		assert(v->subs[subno] != NULL);
+		/* and here's why the recursion got postponed:  it must */
+		/* wait until the skeleton is filled in, because it may */
+		/* hit a backref that wants to copy the filled-in skeleton */
+		dupnfa(v->nfa, v->subs[subno]->begin, v->subs[subno]->end,
+						atom->begin, atom->end);
+		NOERR();
+	}
+
+	/* it's quantifier time; first, turn x{0,...} into x{1,...}|empty */
+	if (m == 0) {
+		EMPTYARC(s2, atom->end);		/* the bypass */
+		assert(PREF(qprefer) != 0);
+		f = COMBINE(qprefer, atom->flags);
+		t = subre(v, '|', f, lp, atom->end);
+		NOERR();
+		t->left = atom;
+		t->right = subre(v, '|', PREF(f), s2, atom->end);
+		NOERR();
+		t->right->left = subre(v, '=', 0, s2, atom->end);
+		NOERR();
+		*atomp = t;
+		atomp = &t->left;
+		m = 1;
+	}
+
+	/* deal with the rest of the quantifier */
+	if (atomtype == BACKREF) {
+		/* special case:  backrefs have internal quantifiers */
+		EMPTYARC(s, atom->begin);	/* empty prefix */
+		/* just stuff everything into atom */
+		repeat(v, atom->begin, atom->end, m, n);
+		atom->min = (short)m;
+		atom->max = (short)n;
+		atom->flags |= COMBINE(qprefer, atom->flags);
+	} else if (m == 1 && n == 1) {
+		/* no/vacuous quantifier:  done */
+		EMPTYARC(s, atom->begin);	/* empty prefix */
+	} else {
+		/* turn x{m,n} into x{m-1,n-1}x, with capturing */
+		/*  parens in only second x */
+		dupnfa(v->nfa, atom->begin, atom->end, s, atom->begin);
+		assert(m >= 1 && m != INFINITY && n >= 1);
+		repeat(v, s, atom->begin, m-1, (n == INFINITY) ? n : n-1);
+		f = COMBINE(qprefer, atom->flags);
+		t = subre(v, '.', f, s, atom->end);	/* prefix and atom */
+		NOERR();
+		t->left = subre(v, '=', PREF(f), s, atom->begin);
+		NOERR();
+		t->right = atom;
+		*atomp = t;
+	}
+
+	/* and finally, look after that postponed recursion */
+	t = top->right;
+	if (!(SEE('|') || SEE(stopper) || SEE(EOS)))
+		t->right = parsebranch(v, stopper, type, atom->end, rp, 1);
+	else {
+		EMPTYARC(atom->end, rp);
+		t->right = subre(v, '=', 0, atom->end, rp);
+	}
+	assert(SEE('|') || SEE(stopper) || SEE(EOS));
+	t->flags |= COMBINE(t->flags, t->right->flags);
+	top->flags |= COMBINE(top->flags, t->flags);
+}
+
+/*
+ - nonword - generate arcs for non-word-character ahead or behind
+ ^ static VOID nonword(struct vars *, int, struct state *, struct state *);
+ */
+static VOID
+nonword(v, dir, lp, rp)
+struct vars *v;
+int dir;			/* AHEAD or BEHIND */
+struct state *lp;
+struct state *rp;
+{
+	int anchor = (dir == AHEAD) ? '$' : '^';
+
+	assert(dir == AHEAD || dir == BEHIND);
+	newarc(v->nfa, anchor, 1, lp, rp);
+	newarc(v->nfa, anchor, 0, lp, rp);
+	colorcomplement(v->nfa, v->cm, dir, v->wordchrs, lp, rp);
+	/* (no need for special attention to \n) */
+}
+
+/*
+ - word - generate arcs for word character ahead or behind
+ ^ static VOID word(struct vars *, int, struct state *, struct state *);
+ */
+static VOID
+word(v, dir, lp, rp)
+struct vars *v;
+int dir;			/* AHEAD or BEHIND */
+struct state *lp;
+struct state *rp;
+{
+	assert(dir == AHEAD || dir == BEHIND);
+	cloneouts(v->nfa, v->wordchrs, lp, rp, dir);
+	/* (no need for special attention to \n) */
+}
+
+/*
+ - scannum - scan a number
+ ^ static int scannum(struct vars *);
+ */
+static int			/* value, <= DUPMAX */
+scannum(v)
+struct vars *v;
+{
+	int n = 0;
+
+	while (SEE(DIGIT) && n < DUPMAX) {
+		n = n*10 + v->nextvalue;
+		NEXT();
+	}
+	if (SEE(DIGIT) || n > DUPMAX) {
+		ERR(REG_BADBR);
+		return 0;
+	}
+	return n;
+}
+
+/*
+ - repeat - replicate subNFA for quantifiers
+ * The duplication sequences used here are chosen carefully so that any
+ * pointers starting out pointing into the subexpression end up pointing into
+ * the last occurrence.  (Note that it may not be strung between the same
+ * left and right end states, however!)  This used to be important for the
+ * subRE tree, although the important bits are now handled by the in-line
+ * code in parse(), and when this is called, it doesn't matter any more.
+ ^ static VOID repeat(struct vars *, struct state *, struct state *, int, int);
+ */
+static VOID
+repeat(v, lp, rp, m, n)
+struct vars *v;
+struct state *lp;
+struct state *rp;
+int m;
+int n;
+{
+#	define	SOME	2
+#	define	INF	3
+#	define	PAIR(x, y)	((x)*4 + (y))
+#	define	REDUCE(x)	( ((x) == INFINITY) ? INF : (((x) > 1) ? SOME : (x)) )
+	CONST int rm = REDUCE(m);
+	CONST int rn = REDUCE(n);
+	struct state *s;
+	struct state *s2;
+
+	switch (PAIR(rm, rn)) {
+	case PAIR(0, 0):		/* empty string */
+		delsub(v->nfa, lp, rp);
+		EMPTYARC(lp, rp);
+		break;
+	case PAIR(0, 1):		/* do as x| */
+		EMPTYARC(lp, rp);
+		break;
+	case PAIR(0, SOME):		/* do as x{1,n}| */
+		repeat(v, lp, rp, 1, n);
+		NOERR();
+		EMPTYARC(lp, rp);
+		break;
+	case PAIR(0, INF):		/* loop x around */
+		s = newstate(v->nfa);
+		NOERR();
+		moveouts(v->nfa, lp, s);
+		moveins(v->nfa, rp, s);
+		EMPTYARC(lp, s);
+		EMPTYARC(s, rp);
+		break;
+	case PAIR(1, 1):		/* no action required */
+		break;
+	case PAIR(1, SOME):		/* do as x{0,n-1}x = (x{1,n-1}|)x */
+		s = newstate(v->nfa);
+		NOERR();
+		moveouts(v->nfa, lp, s);
+		dupnfa(v->nfa, s, rp, lp, s);
+		NOERR();
+		repeat(v, lp, s, 1, n-1);
+		NOERR();
+		EMPTYARC(lp, s);
+		break;
+	case PAIR(1, INF):		/* add loopback arc */
+		s = newstate(v->nfa);
+		s2 = newstate(v->nfa);
+		NOERR();
+		moveouts(v->nfa, lp, s);
+		moveins(v->nfa, rp, s2);
+		EMPTYARC(lp, s);
+		EMPTYARC(s2, rp);
+		EMPTYARC(s2, s);
+		break;
+	case PAIR(SOME, SOME):		/* do as x{m-1,n-1}x */
+		s = newstate(v->nfa);
+		NOERR();
+		moveouts(v->nfa, lp, s);
+		dupnfa(v->nfa, s, rp, lp, s);
+		NOERR();
+		repeat(v, lp, s, m-1, n-1);
+		break;
+	case PAIR(SOME, INF):		/* do as x{m-1,}x */
+		s = newstate(v->nfa);
+		NOERR();
+		moveouts(v->nfa, lp, s);
+		dupnfa(v->nfa, s, rp, lp, s);
+		NOERR();
+		repeat(v, lp, s, m-1, n);
+		break;
+	default:
+		ERR(REG_ASSERT);
+		break;
+	}
+}
+
+/*
+ - bracket - handle non-complemented bracket expression
+ * Also called from cbracket for complemented bracket expressions.
+ ^ static VOID bracket(struct vars *, struct state *, struct state *);
+ */
+static VOID
+bracket(v, lp, rp)
+struct vars *v;
+struct state *lp;
+struct state *rp;
+{
+	assert(SEE('['));
+	NEXT();
+	while (!SEE(']') && !SEE(EOS))
+		brackpart(v, lp, rp);
+	assert(SEE(']') || ISERR());
+	okcolors(v->nfa, v->cm);
+}
+
+/*
+ - cbracket - handle complemented bracket expression
+ * We do it by calling bracket() with dummy endpoints, and then complementing
+ * the result.  The alternative would be to invoke rainbow(), and then delete
+ * arcs as the b.e. is seen... but that gets messy.
+ ^ static VOID cbracket(struct vars *, struct state *, struct state *);
+ */
+static VOID
+cbracket(v, lp, rp)
+struct vars *v;
+struct state *lp;
+struct state *rp;
+{
+	struct state *left = newstate(v->nfa);
+	struct state *right = newstate(v->nfa);
+	struct state *s;
+	struct arc *a;			/* arc from lp */
+	struct arc *ba;			/* arc from left, from bracket() */
+	struct arc *pa;			/* MCCE-prototype arc */
+	color co;
+	chr *p;
+	int i;
+
+	NOERR();
+	bracket(v, left, right);
+	if (v->cflags&REG_NLSTOP)
+		newarc(v->nfa, PLAIN, v->nlcolor, left, right);
+	NOERR();
+
+	assert(lp->nouts == 0);		/* all outarcs will be ours */
+
+	/* easy part of complementing */
+	colorcomplement(v->nfa, v->cm, PLAIN, left, lp, rp);
+	NOERR();
+	if (v->mcces == NULL) {		/* no MCCEs -- we're done */
+		dropstate(v->nfa, left);
+		assert(right->nins == 0);
+		freestate(v->nfa, right);
+		return;
+	}
+
+	/* but complementing gets messy in the presence of MCCEs... */
+	NOTE(REG_ULOCALE);
+	for (p = v->mcces->chrs, i = v->mcces->nchrs; i > 0; p++, i--) {
+		co = GETCOLOR(v->cm, *p);
+		a = findarc(lp, PLAIN, co);
+		ba = findarc(left, PLAIN, co);
+		if (ba == NULL) {
+			assert(a != NULL);
+			freearc(v->nfa, a);
+		} else {
+			assert(a == NULL);
+		}
+		s = newstate(v->nfa);
+		NOERR();
+		newarc(v->nfa, PLAIN, co, lp, s);
+		NOERR();
+		pa = findarc(v->mccepbegin, PLAIN, co);
+		assert(pa != NULL);
+		if (ba == NULL) {	/* easy case, need all of them */
+			cloneouts(v->nfa, pa->to, s, rp, PLAIN);
+			newarc(v->nfa, '$', 1, s, rp);
+			newarc(v->nfa, '$', 0, s, rp);
+			colorcomplement(v->nfa, v->cm, AHEAD, pa->to, s, rp);
+		} else {		/* must be selective */
+			if (findarc(ba->to, '$', 1) == NULL) {
+				newarc(v->nfa, '$', 1, s, rp);
+				newarc(v->nfa, '$', 0, s, rp);
+				colorcomplement(v->nfa, v->cm, AHEAD, pa->to,
+									 s, rp);
+			}
+			for (pa = pa->to->outs; pa != NULL; pa = pa->outchain)
+				if (findarc(ba->to, PLAIN, pa->co) == NULL)
+					newarc(v->nfa, PLAIN, pa->co, s, rp);
+			if (s->nouts == 0)	/* limit of selectivity: none */
+				dropstate(v->nfa, s);	/* frees arc too */
+		}
+		NOERR();
+	}
+
+	delsub(v->nfa, left, right);
+	assert(left->nouts == 0);
+	freestate(v->nfa, left);
+	assert(right->nins == 0);
+	freestate(v->nfa, right);
+}
+			
+/*
+ - brackpart - handle one item (or range) within a bracket expression
+ ^ static VOID brackpart(struct vars *, struct state *, struct state *);
+ */
+static VOID
+brackpart(v, lp, rp)
+struct vars *v;
+struct state *lp;
+struct state *rp;
+{
+	celt startc;
+	celt endc;
+	struct cvec *cv;
+	chr *startp;
+	chr *endp;
+	chr c[1];
+
+	/* parse something, get rid of special cases, take shortcuts */
+	switch (v->nexttype) {
+	case RANGE:			/* a-b-c or other botch */
+		ERR(REG_ERANGE);
+		return;
+		break;
+	case PLAIN:
+		c[0] = v->nextvalue;
+		NEXT();
+		/* shortcut for ordinary chr (not range, not MCCE leader) */
+		if (!SEE(RANGE) && !ISCELEADER(v, c[0])) {
+			onechr(v, c[0], lp, rp);
+			return;
+		}
+		startc = element(v, c, c+1);
+		NOERR();
+		break;
+	case COLLEL:
+		startp = v->now;
+		endp = scanplain(v);
+		INSIST(startp < endp, REG_ECOLLATE);
+		NOERR();
+		startc = element(v, startp, endp);
+		NOERR();
+		break;
+	case ECLASS:
+		startp = v->now;
+		endp = scanplain(v);
+		INSIST(startp < endp, REG_ECOLLATE);
+		NOERR();
+		startc = element(v, startp, endp);
+		NOERR();
+		cv = eclass(v, startc, (v->cflags&REG_ICASE));
+		NOERR();
+		dovec(v, cv, lp, rp);
+		return;
+		break;
+	case CCLASS:
+		startp = v->now;
+		endp = scanplain(v);
+		INSIST(startp < endp, REG_ECTYPE);
+		NOERR();
+		cv = cclass(v, startp, endp, (v->cflags&REG_ICASE));
+		NOERR();
+		dovec(v, cv, lp, rp);
+		return;
+		break;
+	default:
+		ERR(REG_ASSERT);
+		return;
+		break;
+	}
+
+	if (SEE(RANGE)) {
+		NEXT();
+		switch (v->nexttype) {
+		case PLAIN:
+		case RANGE:
+			c[0] = v->nextvalue;
+			NEXT();
+			endc = element(v, c, c+1);
+			NOERR();
+			break;
+		case COLLEL:
+			startp = v->now;
+			endp = scanplain(v);
+			INSIST(startp < endp, REG_ECOLLATE);
+			NOERR();
+			endc = element(v, startp, endp);
+			NOERR();
+			break;
+		default:
+			ERR(REG_ERANGE);
+			return;
+			break;
+		}
+	} else
+		endc = startc;
+
+	/*
+	 * Ranges are unportable.  Actually, standard C does
+	 * guarantee that digits are contiguous, but making
+	 * that an exception is just too complicated.
+	 */
+	if (startc != endc)
+		NOTE(REG_UUNPORT);
+	cv = range(v, startc, endc, (v->cflags&REG_ICASE));
+	NOERR();
+	dovec(v, cv, lp, rp);
+}
+
+/*
+ - scanplain - scan PLAIN contents of [. etc.
+ * Certain bits of trickery in lex.c know that this code does not try
+ * to look past the final bracket of the [. etc.
+ ^ static chr *scanplain(struct vars *);
+ */
+static chr *			/* just after end of sequence */
+scanplain(v)
+struct vars *v;
+{
+	chr *endp;
+
+	assert(SEE(COLLEL) || SEE(ECLASS) || SEE(CCLASS));
+	NEXT();
+
+	endp = v->now;
+	while (SEE(PLAIN)) {
+		endp = v->now;
+		NEXT();
+	}
+
+	assert(SEE(END) || ISERR());
+	NEXT();
+
+	return endp;
+}
+
+/*
+ - leaders - process a cvec of collating elements to also include leaders
+ * Also gives all characters involved their own colors, which is almost
+ * certainly necessary, and sets up little disconnected subNFA.
+ ^ static VOID leaders(struct vars *, struct cvec *);
+ */
+static VOID
+leaders(v, cv)
+struct vars *v;
+struct cvec *cv;
+{
+	int mcce;
+	chr *p;
+	chr leader;
+	struct state *s;
+	struct arc *a;
+
+	v->mccepbegin = newstate(v->nfa);
+	v->mccepend = newstate(v->nfa);
+	NOERR();
+
+	for (mcce = 0; mcce < cv->nmcces; mcce++) {
+		p = cv->mcces[mcce];
+		leader = *p;
+		if (!haschr(cv, leader)) {
+			addchr(cv, leader);
+			s = newstate(v->nfa);
+			newarc(v->nfa, PLAIN, subcolor(v->cm, leader),
+							v->mccepbegin, s);
+			okcolors(v->nfa, v->cm);
+		} else {
+			a = findarc(v->mccepbegin, PLAIN,
+						GETCOLOR(v->cm, leader));
+			assert(a != NULL);
+			s = a->to;
+			assert(s != v->mccepend);
+		}
+		p++;
+		assert(*p != 0 && *(p+1) == 0);	/* only 2-char MCCEs for now */
+		newarc(v->nfa, PLAIN, subcolor(v->cm, *p), s, v->mccepend);
+		okcolors(v->nfa, v->cm);
+	}
+}
+
+/*
+ - onechr - fill in arcs for a plain character, and possible case complements
+ * This is mostly a shortcut for efficient handling of the common case.
+ ^ static VOID onechr(struct vars *, pchr, struct state *, struct state *);
+ */
+static VOID
+onechr(v, c, lp, rp)
+struct vars *v;
+pchr c;
+struct state *lp;
+struct state *rp;
+{
+	if (!(v->cflags&REG_ICASE)) {
+		newarc(v->nfa, PLAIN, subcolor(v->cm, c), lp, rp);
+		return;
+	}
+
+	/* rats, need general case anyway... */
+	dovec(v, allcases(v, c), lp, rp);
+}
+
+/*
+ - dovec - fill in arcs for each element of a cvec
+ * This one has to handle the messy cases, like MCCEs and MCCE leaders.
+ ^ static VOID dovec(struct vars *, struct cvec *, struct state *,
+ ^ 	struct state *);
+ */
+static VOID
+dovec(v, cv, lp, rp)
+struct vars *v;
+struct cvec *cv;
+struct state *lp;
+struct state *rp;
+{
+	chr ch, from, to;
+	celt ce;
+	chr *p;
+	int i;
+	color co;
+	struct cvec *leads;
+	struct arc *a;
+	struct arc *pa;		/* arc in prototype */
+	struct state *s;
+	struct state *ps;	/* state in prototype */
+
+	/* need a place to store leaders, if any */
+	if (nmcces(v) > 0) {
+		assert(v->mcces != NULL);
+		if (v->cv2 == NULL || v->cv2->nchrs < v->mcces->nchrs) {
+			if (v->cv2 != NULL)
+				free(v->cv2);
+			v->cv2 = newcvec(v->mcces->nchrs, 0, v->mcces->nmcces);
+			NOERR();
+			leads = v->cv2;
+		} else
+			leads = clearcvec(v->cv2);
+	} else
+		leads = NULL;
+
+	/* first, get the ordinary characters out of the way */
+	for (p = cv->chrs, i = cv->nchrs; i > 0; p++, i--) {
+		ch = *p;
+		if (!ISCELEADER(v, ch))
+			newarc(v->nfa, PLAIN, subcolor(v->cm, ch), lp, rp);
+		else {
+			assert(singleton(v->cm, ch));
+			assert(leads != NULL);
+			if (!haschr(leads, ch))
+				addchr(leads, ch);
+		}
+	}
+
+	/* and the ranges */
+	for (p = cv->ranges, i = cv->nranges; i > 0; p += 2, i--) {
+		from = *p;
+		to = *(p+1);
+		while (from <= to && (ce = nextleader(v, from, to)) != NOCELT) {
+			if (from < ce)
+				subrange(v, from, ce - 1, lp, rp);
+			assert(singleton(v->cm, ce));
+			assert(leads != NULL);
+			if (!haschr(leads, ce))
+				addchr(leads, ce);
+			from = ce + 1;
+		}
+		if (from <= to)
+			subrange(v, from, to, lp, rp);
+	}
+
+	if ((leads == NULL || leads->nchrs == 0) && cv->nmcces == 0)
+		return;
+
+	/* deal with the MCCE leaders */
+	NOTE(REG_ULOCALE);
+	for (p = leads->chrs, i = leads->nchrs; i > 0; p++, i--) {
+		co = GETCOLOR(v->cm, *p);
+		a = findarc(lp, PLAIN, co);
+		if (a != NULL)
+			s = a->to;
+		else {
+			s = newstate(v->nfa);
+			NOERR();
+			newarc(v->nfa, PLAIN, co, lp, s);
+			NOERR();
+		}
+		pa = findarc(v->mccepbegin, PLAIN, co);
+		assert(pa != NULL);
+		ps = pa->to;
+		newarc(v->nfa, '$', 1, s, rp);
+		newarc(v->nfa, '$', 0, s, rp);
+		colorcomplement(v->nfa, v->cm, AHEAD, ps, s, rp);
+		NOERR();
+	}
+
+	/* and the MCCEs */
+	for (i = 0; i < cv->nmcces; i++) {
+		p = cv->mcces[i];
+		assert(singleton(v->cm, *p));
+		if (!singleton(v->cm, *p)) {
+			ERR(REG_ASSERT);
+			return;
+		}
+		ch = *p++;
+		co = GETCOLOR(v->cm, ch);
+		a = findarc(lp, PLAIN, co);
+		if (a != NULL)
+			s = a->to;
+		else {
+			s = newstate(v->nfa);
+			NOERR();
+			newarc(v->nfa, PLAIN, co, lp, s);
+			NOERR();
+		}
+		assert(*p != 0);	/* at least two chars */
+		assert(singleton(v->cm, *p));
+		ch = *p++;
+		co = GETCOLOR(v->cm, ch);
+		assert(*p == 0);	/* and only two, for now */
+		newarc(v->nfa, PLAIN, co, s, rp);
+		NOERR();
+	}
+}
+
+/*
+ - nextleader - find next MCCE leader within range
+ ^ static celt nextleader(struct vars *, pchr, pchr);
+ */
+static celt			/* NOCELT means none */
+nextleader(v, from, to)
+struct vars *v;
+pchr from;
+pchr to;
+{
+	int i;
+	chr *p;
+	chr ch;
+	celt it = NOCELT;
+
+	if (v->mcces == NULL)
+		return it;
+
+	for (i = v->mcces->nchrs, p = v->mcces->chrs; i > 0; i--, p++) {
+		ch = *p;
+		if (from <= ch && ch <= to)
+			if (it == NOCELT || ch < it)
+				it = ch;
+	}
+	return it;
+}
+
+/*
+ - wordchrs - set up word-chr list for word-boundary stuff, if needed
+ * The list is kept as a bunch of arcs between two dummy states; it's
+ * disposed of by the unreachable-states sweep in NFA optimization.
+ * Does NEXT().  Must not be called from any unusual lexical context.
+ * This should be reconciled with the \w etc. handling in lex.c, and
+ * should be cleaned up to reduce dependencies on input scanning.
+ ^ static VOID wordchrs(struct vars *);
+ */
+static VOID
+wordchrs(v)
+struct vars *v;
+{
+	struct state *left;
+	struct state *right;
+
+	if (v->wordchrs != NULL) {
+		NEXT();		/* for consistency */
+		return;
+	}
+
+	left = newstate(v->nfa);
+	right = newstate(v->nfa);
+	NOERR();
+	/* fine point:  implemented with [::], and lexer will set REG_ULOCALE */
+	lexword(v);
+	NEXT();
+	assert(v->savenow != NULL && SEE('['));
+	bracket(v, left, right);
+	assert((v->savenow != NULL && SEE(']')) || ISERR());
+	NEXT();
+	NOERR();
+	v->wordchrs = left;
+}
+
+/*
+ - subre - allocate a subre
+ ^ static struct subre *subre(struct vars *, int, int, struct state *,
+ ^	struct state *);
+ */
+static struct subre *
+subre(v, op, flags, begin, end)
+struct vars *v;
+int op;
+int flags;
+struct state *begin;
+struct state *end;
+{
+	struct subre *ret;
+
+	ret = v->treefree;
+	if (ret != NULL)
+		v->treefree = ret->left;
+	else {
+		ret = (struct subre *)MALLOC(sizeof(struct subre));
+		if (ret == NULL) {
+			ERR(REG_ESPACE);
+			return NULL;
+		}
+		ret->chain = v->treechain;
+		v->treechain = ret;
+	}
+
+	assert(strchr("|.b(=", op) != NULL);
+
+	ret->op = op;
+	ret->flags = flags;
+	ret->retry = 0;
+	ret->subno = 0;
+	ret->min = ret->max = 1;
+	ret->left = NULL;
+	ret->right = NULL;
+	ret->begin = begin;
+	ret->end = end;
+	ZAPCNFA(ret->cnfa);
+
+	return ret;
+}
+
+/*
+ - freesubre - free a subRE subtree
+ ^ static VOID freesubre(struct vars *, struct subre *);
+ */
+static VOID
+freesubre(v, sr)
+struct vars *v;			/* might be NULL */
+struct subre *sr;
+{
+	if (sr == NULL)
+		return;
+
+	if (sr->left != NULL)
+		freesubre(v, sr->left);
+	if (sr->right != NULL)
+		freesubre(v, sr->right);
+
+	freesrnode(v, sr);
+}
+
+/*
+ - freesrnode - free one node in a subRE subtree
+ ^ static VOID freesrnode(struct vars *, struct subre *);
+ */
+static VOID
+freesrnode(v, sr)
+struct vars *v;			/* might be NULL */
+struct subre *sr;
+{
+	if (sr == NULL)
+		return;
+
+	if (!NULLCNFA(sr->cnfa))
+		freecnfa(&sr->cnfa);
+	sr->flags = 0;
+
+	if (v != NULL) {
+		sr->left = v->treefree;
+		v->treefree = sr;
+	} else
+		FREE(sr);
+}
+
+/*
+ - optst - optimize a subRE subtree
+ ^ static VOID optst(struct vars *, struct subre *);
+ */
+static VOID
+optst(v, t)
+struct vars *v;
+struct subre *t;
+{
+	if (t == NULL)
+		return;
+
+	/* recurse through children */
+	if (t->left != NULL)
+		optst(v, t->left);
+	if (t->right != NULL)
+		optst(v, t->right);
+}
+
+/*
+ - numst - number tree nodes (assigning retry indexes)
+ ^ static int numst(struct subre *, int);
+ */
+static int			/* next number */
+numst(t, start)
+struct subre *t;
+int start;			/* starting point for subtree numbers */
+{
+	int i;
+
+	assert(t != NULL);
+
+	i = start;
+	t->retry = (short)i++;
+	if (t->left != NULL)
+		i = numst(t->left, i);
+	if (t->right != NULL)
+		i = numst(t->right, i);
+	return i;
+}
+
+/*
+ - markst - mark tree nodes as INUSE
+ ^ static VOID markst(struct subre *);
+ */
+static VOID
+markst(t)
+struct subre *t;
+{
+	assert(t != NULL);
+
+	t->flags |= INUSE;
+	if (t->left != NULL)
+		markst(t->left);
+	if (t->right != NULL)
+		markst(t->right);
+}
+
+/*
+ - cleanst - free any tree nodes not marked INUSE
+ ^ static VOID cleanst(struct vars *);
+ */
+static VOID
+cleanst(v)
+struct vars *v;
+{
+	struct subre *t;
+	struct subre *next;
+
+	for (t = v->treechain; t != NULL; t = next) {
+		next = t->chain;
+		if (!(t->flags&INUSE))
+			FREE(t);
+	}
+	v->treechain = NULL;
+	v->treefree = NULL;		/* just on general principles */
+}
+
+/*
+ - nfatree - turn a subRE subtree into a tree of compacted NFAs
+ ^ static long nfatree(struct vars *, struct subre *, FILE *);
+ */
+static long			/* optimize results from top node */
+nfatree(v, t, f)
+struct vars *v;
+struct subre *t;
+FILE *f;			/* for debug output */
+{
+	assert(t != NULL && t->begin != NULL);
+
+	if (t->left != NULL)
+		(DISCARD)nfatree(v, t->left, f);
+	if (t->right != NULL)
+		(DISCARD)nfatree(v, t->right, f);
+
+	return nfanode(v, t, f);
+}
+
+/*
+ - nfanode - do one NFA for nfatree
+ ^ static long nfanode(struct vars *, struct subre *, FILE *);
+ */
+static long			/* optimize results */
+nfanode(v, t, f)
+struct vars *v;
+struct subre *t;
+FILE *f;			/* for debug output */
+{
+	struct nfa *nfa;
+	long ret = 0;
+	char idbuf[50];
+
+	assert(t->begin != NULL);
+
+	if (f != NULL)
+		fprintf(f, "\n\n\n========= TREE NODE %s ==========\n",
+						stid(t, idbuf, sizeof(idbuf)));
+	nfa = newnfa(v, v->cm, v->nfa);
+	NOERRZ();
+	dupnfa(nfa, t->begin, t->end, nfa->init, nfa->final);
+	if (!ISERR()) {
+		specialcolors(nfa);
+		ret = optimize(nfa, f);
+	}
+	if (!ISERR())
+		compact(nfa, &t->cnfa);
+
+	freenfa(nfa);
+	return ret;
+}
+
+/*
+ - newlacon - allocate a lookahead-constraint subRE
+ ^ static int newlacon(struct vars *, struct state *, struct state *, int);
+ */
+static int			/* lacon number */
+newlacon(v, begin, end, pos)
+struct vars *v;
+struct state *begin;
+struct state *end;
+int pos;
+{
+	int n;
+	struct subre *sub;
+
+	if (v->nlacons == 0) {
+		v->lacons = (struct subre *)MALLOC(2 * sizeof(struct subre));
+		n = 1;		/* skip 0th */
+		v->nlacons = 2;
+	} else {
+		v->lacons = (struct subre *)REALLOC(v->lacons,
+					(v->nlacons+1)*sizeof(struct subre));
+		n = v->nlacons++;
+	}
+	if (v->lacons == NULL) {
+		ERR(REG_ESPACE);
+		return 0;
+	}
+	sub = &v->lacons[n];
+	sub->begin = begin;
+	sub->end = end;
+	sub->subno = pos;
+	ZAPCNFA(sub->cnfa);
+	return n;
+}
+
+/*
+ - freelacons - free lookahead-constraint subRE vector
+ ^ static VOID freelacons(struct subre *, int);
+ */
+static VOID
+freelacons(subs, n)
+struct subre *subs;
+int n;
+{
+	struct subre *sub;
+	int i;
+
+	assert(n > 0);
+	for (sub = subs + 1, i = n - 1; i > 0; sub++, i--)	/* no 0th */
+		if (!NULLCNFA(sub->cnfa))
+			freecnfa(&sub->cnfa);
+	FREE(subs);
+}
+
+/*
+ - rfree - free a whole RE (insides of regfree)
+ ^ static VOID rfree(regex_t *);
+ */
+static VOID
+rfree(re)
+regex_t *re;
+{
+	struct guts *g;
+
+	if (re == NULL || re->re_magic != REMAGIC)
+		return;
+
+	re->re_magic = 0;	/* invalidate RE */
+	g = (struct guts *)re->re_guts;
+	re->re_guts = NULL;
+	re->re_fns = NULL;
+	g->magic = 0;
+	freecm(&g->cmap);
+	if (g->tree != NULL)
+		freesubre((struct vars *)NULL, g->tree);
+	if (g->lacons != NULL)
+		freelacons(g->lacons, g->nlacons);
+	if (!NULLCNFA(g->search))
+		freecnfa(&g->search);
+	FREE(g);
+}
+
+/*
+ - dump - dump an RE in human-readable form
+ ^ static VOID dump(regex_t *, FILE *);
+ */
+static VOID
+dump(re, f)
+regex_t *re;
+FILE *f;
+{
+#ifdef REG_DEBUG
+	struct guts *g;
+	int i;
+
+	if (re->re_magic != REMAGIC)
+		fprintf(f, "bad magic number (0x%x not 0x%x)\n", re->re_magic,
+								REMAGIC);
+	if (re->re_guts == NULL) {
+		fprintf(f, "NULL guts!!!\n");
+		return;
+	}
+	g = (struct guts *)re->re_guts;
+	if (g->magic != GUTSMAGIC)
+		fprintf(f, "bad guts magic number (0x%x not 0x%x)\n", g->magic,
+								GUTSMAGIC);
+
+	fprintf(f, "\n\n\n========= DUMP ==========\n");
+	fprintf(f, "nsub %d, info 0%lo, csize %d, ntree %d\n", 
+		re->re_nsub, re->re_info, re->re_csize, g->ntree);
+
+	dumpcolors(&g->cmap, f);
+	if (!NULLCNFA(g->search)) {
+		printf("\nsearch:\n");
+		dumpcnfa(&g->search, f);
+	}
+	for (i = 1; i < g->nlacons; i++) {
+		fprintf(f, "\nla%d (%s):\n", i,
+				(g->lacons[i].subno) ? "positive" : "negative");
+		dumpcnfa(&g->lacons[i].cnfa, f);
+	}
+	fprintf(f, "\n");
+	dumpst(g->tree, f, 0);
+#endif
+}
+
+/*
+ - dumpst - dump a subRE tree
+ ^ static VOID dumpst(struct subre *, FILE *, int);
+ */
+static VOID
+dumpst(t, f, nfapresent)
+struct subre *t;
+FILE *f;
+int nfapresent;			/* is the original NFA still around? */
+{
+	if (t == NULL)
+		fprintf(f, "null tree\n");
+	else
+		stdump(t, f, nfapresent);
+	fflush(f);
+}
+
+/*
+ - stdump - recursive guts of dumpst
+ ^ static VOID stdump(struct subre *, FILE *, int);
+ */
+static VOID
+stdump(t, f, nfapresent)
+struct subre *t;
+FILE *f;
+int nfapresent;			/* is the original NFA still around? */
+{
+	char idbuf[50];
+
+	fprintf(f, "%s. `%c'", stid(t, idbuf, sizeof(idbuf)), t->op);
+	if (t->flags&LONGER)
+		fprintf(f, " longest");
+	if (t->flags&SHORTER)
+		fprintf(f, " shortest");
+	if (t->flags&MIXED)
+		fprintf(f, " hasmixed");
+	if (t->flags&CAP)
+		fprintf(f, " hascapture");
+	if (t->flags&BACKR)
+		fprintf(f, " hasbackref");
+	if (!(t->flags&INUSE))
+		fprintf(f, " UNUSED");
+	if (t->subno != 0)
+		fprintf(f, " (#%d)", t->subno);
+	if (t->min != 1 || t->max != 1) {
+		fprintf(f, " {%d,", t->min);
+		if (t->max != INFINITY)
+			fprintf(f, "%d", t->max);
+		fprintf(f, "}");
+	}
+	if (nfapresent)
+		fprintf(f, " %ld-%ld", (long)t->begin->no, (long)t->end->no);
+	if (t->left != NULL)
+		fprintf(f, " L:%s", stid(t->left, idbuf, sizeof(idbuf)));
+	if (t->right != NULL)
+		fprintf(f, " R:%s", stid(t->right, idbuf, sizeof(idbuf)));
+	if (!NULLCNFA(t->cnfa)) {
+		fprintf(f, "\n");
+		dumpcnfa(&t->cnfa, f);
+		fprintf(f, "\n");
+	}
+	if (t->left != NULL)
+		stdump(t->left, f, nfapresent);
+	if (t->right != NULL)
+		stdump(t->right, f, nfapresent);
+}
+
+/*
+ - stid - identify a subtree node for dumping
+ ^ static char *stid(struct subre *, char *, size_t);
+ */
+static char *			/* points to buf or constant string */
+stid(t, buf, bufsize)
+struct subre *t;
+char *buf;
+size_t bufsize;
+{
+	/* big enough for hex int or decimal t->retry? */
+	if (bufsize < sizeof(int)*2 + 3 || bufsize < sizeof(t->retry)*3 + 1)
+		return "unable";
+	if (t->retry != 0)
+		sprintf(buf, "%d", t->retry);
+	else
+		sprintf(buf, "0x%x", (int)t);	/* may lose bits, that's okay */
+	return buf;
+}
+
+#include "regc_lex.c"
+#include "regc_color.c"
+#include "regc_nfa.c"
+#include "regc_cvec.c"
+#include "regc_locale.c"