===================================================================
RCS file: /cvs/mandoc/eqn.c,v
retrieving revision 1.4
retrieving revision 1.13
diff -u -p -r1.4 -r1.13
--- mandoc/eqn.c	2011/03/22 09:48:13	1.4
+++ mandoc/eqn.c	2011/07/21 11:34:53	1.13
@@ -1,4 +1,4 @@
-/*	$Id: eqn.c,v 1.4 2011/03/22 09:48:13 kristaps Exp $ */
+/*	$Id: eqn.c,v 1.13 2011/07/21 11:34:53 kristaps Exp $ */
 /*
  * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  *
@@ -28,54 +28,364 @@
 #include "libmandoc.h"
 #include "libroff.h"
 
+#define	EQN_NEST_MAX	 128 /* maximum nesting of defines */
+#define	EQN_MSG(t, x)	 mandoc_msg((t), (x)->parse, (x)->eqn.ln, (x)->eqn.pos, NULL)
+
+struct	eqnpart {
+	const char	*name;
+	size_t		 sz;
+	int		(*fp)(struct eqn_node *);
+};
+
+enum	eqnpartt {
+	EQN_DEFINE = 0,
+	EQN_SET,
+	EQN_UNDEF,
+	EQN__MAX
+};
+
+static	void		 eqn_box_free(struct eqn_box *);
+static	struct eqn_def	*eqn_def_find(struct eqn_node *, 
+				const char *, size_t);
+static	int		 eqn_do_define(struct eqn_node *);
+static	int		 eqn_do_ign2(struct eqn_node *);
+static	int		 eqn_do_undef(struct eqn_node *);
+static	const char	*eqn_nexttok(struct eqn_node *, size_t *);
+static	const char	*eqn_next(struct eqn_node *, char, size_t *);
+static	int		 eqn_box(struct eqn_node *, struct eqn_box *);
+
+static	const struct eqnpart eqnparts[EQN__MAX] = {
+	{ "define", 6, eqn_do_define }, /* EQN_DEFINE */
+	{ "set", 3, eqn_do_ign2 }, /* EQN_SET */
+	{ "undef", 5, eqn_do_undef }, /* EQN_UNDEF */
+};
+
 /* ARGSUSED */
 enum rofferr
-eqn_read(struct eqn_node **epp, int ln, const char *p, int offs)
+eqn_read(struct eqn_node **epp, int ln, 
+		const char *p, int pos, int *offs)
 {
 	size_t		 sz;
 	struct eqn_node	*ep;
+	enum rofferr	 er;
 
+	ep = *epp;
+
+	/*
+	 * If we're the terminating mark, unset our equation status and
+	 * validate the full equation.
+	 */
+
 	if (0 == strcmp(p, ".EN")) {
+		er = eqn_end(ep);
 		*epp = NULL;
-		return(ROFF_EQN);
+		return(er);
 	}
 
-	ep = *epp;
+	/*
+	 * Build up the full string, replacing all newlines with regular
+	 * whitespace.
+	 */
 
-	sz = strlen(&p[offs]);
-	ep->eqn.data = mandoc_realloc(ep->eqn.data, ep->eqn.sz + sz + 1);
-	if (0 == ep->eqn.sz)
-		*ep->eqn.data = '\0';
+	sz = strlen(p + pos) + 1;
+	ep->data = mandoc_realloc(ep->data, ep->sz + sz + 1);
 
-	ep->eqn.sz += sz;
-	strlcat(ep->eqn.data, &p[offs], ep->eqn.sz + 1);
+	/* First invocation: nil terminate the string. */
+
+	if (0 == ep->sz)
+		*ep->data = '\0';
+
+	ep->sz += sz;
+	strlcat(ep->data, p + pos, ep->sz + 1);
+	strlcat(ep->data, " ", ep->sz + 1);
 	return(ROFF_IGN);
 }
 
 struct eqn_node *
-eqn_alloc(int pos, int line)
+eqn_alloc(int pos, int line, struct mparse *parse)
 {
 	struct eqn_node	*p;
 
 	p = mandoc_calloc(1, sizeof(struct eqn_node));
-	p->eqn.line = line;
+	p->parse = parse;
+	p->eqn.ln = line;
 	p->eqn.pos = pos;
 
 	return(p);
 }
 
-/* ARGSUSED */
-void
-eqn_end(struct eqn_node *e)
+enum rofferr
+eqn_end(struct eqn_node *ep)
 {
+	struct eqn_box	*root;
 
-	/* Nothing to do. */
+	ep->eqn.root = root = 
+		mandoc_calloc(1, sizeof(struct eqn_box));
+	root->type = EQN_ROOT;
+
+	if (0 == ep->sz)
+		return(ROFF_IGN);
+
+	/*
+	 * Validate the expression.
+	 * Use the grammar found in the literature.
+	 */
+
+	return(eqn_box(ep, root) < 0 ? ROFF_IGN : ROFF_EQN);
 }
 
+static int
+eqn_box(struct eqn_node *ep, struct eqn_box *last)
+{
+	size_t		 sz;
+	const char	*start;
+	int		 i, nextc;
+	struct eqn_box	*bp;
+
+	nextc = 1;
+again:
+	if (NULL == (start = eqn_nexttok(ep, &sz)))
+		return(0);
+
+	for (i = 0; i < (int)EQN__MAX; i++) {
+		if (eqnparts[i].sz != sz)
+			continue;
+		if (strncmp(eqnparts[i].name, start, sz))
+			continue;
+		if ( ! (*eqnparts[i].fp)(ep))
+			return(-1);
+
+		goto again;
+	} 
+
+	bp = mandoc_calloc(1, sizeof(struct eqn_box));
+	bp->type = EQN_TEXT;
+
+	if (nextc)
+		last->child = bp;
+	else
+		last->next = bp;
+
+	bp->text = mandoc_malloc(sz + 1);
+	*bp->text = '\0';
+	strlcat(bp->text, start, sz + 1);
+
+	last = bp;
+	nextc = 0;
+	goto again;
+}
+
 void
 eqn_free(struct eqn_node *p)
 {
+	int		 i;
 
-	free(p->eqn.data);
+	eqn_box_free(p->eqn.root);
+
+	for (i = 0; i < (int)p->defsz; i++) {
+		free(p->defs[i].key);
+		free(p->defs[i].val);
+	}
+
+	free(p->data);
+	free(p->defs);
 	free(p);
+}
+
+static void
+eqn_box_free(struct eqn_box *bp)
+{
+
+	if (bp->child)
+		eqn_box_free(bp->child);
+	if (bp->next)
+		eqn_box_free(bp->next);
+
+	free(bp->text);
+	free(bp);
+}
+
+static const char *
+eqn_nexttok(struct eqn_node *ep, size_t *sz)
+{
+
+	return(eqn_next(ep, '"', sz));
+}
+
+static const char *
+eqn_next(struct eqn_node *ep, char quote, size_t *sz)
+{
+	char		*start, *next;
+	int		 q, diff, lim;
+	size_t		 sv, ssz;
+	struct eqn_def	*def;
+
+	if (NULL == sz)
+		sz = &ssz;
+
+	lim = 0;
+	sv = ep->cur;
+again:
+	/* Prevent self-definitions. */
+
+	if (lim >= EQN_NEST_MAX) {
+		EQN_MSG(MANDOCERR_EQNNEST, ep);
+		return(NULL);
+	}
+
+	ep->cur = sv;
+	start = &ep->data[(int)ep->cur];
+	q = 0;
+
+	if ('\0' == *start)
+		return(NULL);
+
+	if (quote == *start) {
+		ep->cur++;
+		q = 1;
+	}
+
+	start = &ep->data[(int)ep->cur];
+	next = q ? strchr(start, quote) : strchr(start, ' ');
+
+	if (NULL != next) {
+		*sz = (size_t)(next - start);
+		ep->cur += *sz;
+		if (q)
+			ep->cur++;
+		while (' ' == ep->data[(int)ep->cur])
+			ep->cur++;
+	} else {
+		if (q)
+			EQN_MSG(MANDOCERR_BADQUOTE, ep);
+		next = strchr(start, '\0');
+		*sz = (size_t)(next - start);
+		ep->cur += *sz;
+	}
+
+	/* Quotes aren't expanded for values. */
+
+	if (q)
+		return(start);
+
+	if (NULL != (def = eqn_def_find(ep, start, *sz))) {
+		diff = def->valsz - *sz;
+
+		if (def->valsz > *sz) {
+			ep->sz += diff;
+			ep->data = mandoc_realloc(ep->data, ep->sz + 1);
+			ep->data[ep->sz] = '\0';
+			start = &ep->data[(int)sv];
+		}
+
+		diff = def->valsz - *sz;
+		memmove(start + *sz + diff, start + *sz, 
+				(strlen(start) - *sz) + 1);
+		memcpy(start, def->val, def->valsz);
+		goto again;
+	}
+
+	return(start);
+}
+
+static int
+eqn_do_ign2(struct eqn_node *ep)
+{
+	const char	*start;
+
+	if (NULL == (start = eqn_nexttok(ep, NULL)))
+		EQN_MSG(MANDOCERR_EQNARGS, ep);
+	else if (NULL == (start = eqn_nexttok(ep, NULL)))
+		EQN_MSG(MANDOCERR_EQNARGS, ep);
+	else
+		return(1);
+
+	return(0);
+}
+
+static int
+eqn_do_define(struct eqn_node *ep)
+{
+	const char	*start;
+	size_t		 sz;
+	struct eqn_def	*def;
+	int		 i;
+
+	if (NULL == (start = eqn_nexttok(ep, &sz))) {
+		EQN_MSG(MANDOCERR_EQNARGS, ep);
+		return(0);
+	}
+
+	/* 
+	 * Search for a key that already exists. 
+	 * Create a new key if none is found.
+	 */
+
+	if (NULL == (def = eqn_def_find(ep, start, sz))) {
+		/* Find holes in string array. */
+		for (i = 0; i < (int)ep->defsz; i++)
+			if (0 == ep->defs[i].keysz)
+				break;
+
+		if (i == (int)ep->defsz) {
+			ep->defsz++;
+			ep->defs = mandoc_realloc
+				(ep->defs, ep->defsz * 
+				 sizeof(struct eqn_def));
+			ep->defs[i].key = ep->defs[i].val = NULL;
+		}
+
+		ep->defs[i].keysz = sz;
+		ep->defs[i].key = mandoc_realloc
+			(ep->defs[i].key, sz + 1);
+
+		memcpy(ep->defs[i].key, start, sz);
+		ep->defs[i].key[(int)sz] = '\0';
+		def = &ep->defs[i];
+	}
+
+	start = eqn_next(ep, ep->data[(int)ep->cur], &sz);
+
+	if (NULL == start) {
+		EQN_MSG(MANDOCERR_EQNARGS, ep);
+		return(0);
+	}
+
+	def->valsz = sz;
+	def->val = mandoc_realloc(def->val, sz + 1);
+	memcpy(def->val, start, sz);
+	def->val[(int)sz] = '\0';
+
+	/*fprintf(stderr, "Defining: [%s], [%s]\n", 
+			def->key, def->val);*/
+	return(1);
+}
+
+static int
+eqn_do_undef(struct eqn_node *ep)
+{
+	const char	*start;
+	struct eqn_def	*def;
+	size_t		 sz;
+
+	if (NULL == (start = eqn_nexttok(ep, &sz))) {
+		EQN_MSG(MANDOCERR_EQNARGS, ep);
+		return(0);
+	} else if (NULL != (def = eqn_def_find(ep, start, sz)))
+		def->keysz = 0;
+
+	return(1);
+}
+
+static struct eqn_def *
+eqn_def_find(struct eqn_node *ep, const char *key, size_t sz)
+{
+	int		 i;
+
+	for (i = 0; i < (int)ep->defsz; i++) 
+		if (ep->defs[i].keysz && ep->defs[i].keysz == sz &&
+				0 == strncmp(ep->defs[i].key, key, sz))
+			return(&ep->defs[i]);
+
+	return(NULL);
 }