Add initial EQN support to mandoc. This parses, then throws away, data

between EQ and EN roff blocks.  EQN is different from TBL in that data
after .EQ is unilaterally considered an equation until an .EN.  Thus,
there's no need to jump through hoops in having table spans and so on.
This is ONLY the parse code framework in libroff.  EQN is not yet passed
into the backends.

1 files changed, 72 insertions, 9 deletions

diff --git a/roff.c b/roff.c
index b885a5f2..91e4dcbd 100644
--- a/roff.c
+++ b/roff.c
@@ -64,6 +64,8 @@ enum	rofft {
 	ROFF_TS,
 	ROFF_TE,
 	ROFF_T_,
+	ROFF_EQ,
+	ROFF_EN,
 	ROFF_cblock,
 	ROFF_ccond, /* FIXME: remove this. */
 	ROFF_USERDEF,
@@ -93,6 +95,9 @@ struct	roff {
 	struct tbl_node	*first_tbl; /* first table parsed */
 	struct tbl_node	*last_tbl; /* last table parsed */
 	struct tbl_node	*tbl; /* current table being parsed */
+	struct eqn_node	*last_eqn; /* last equation parsed */
+	struct eqn_node	*first_eqn; /* first equation parsed */
+	struct eqn_node	*eqn; /* current equation being parsed */
 };
 
 struct	roffnode {
@@ -151,6 +156,8 @@ static	void		 roff_setstr(struct roff *,
 static	enum rofferr	 roff_so(ROFF_ARGS);
 static	enum rofferr	 roff_TE(ROFF_ARGS);
 static	enum rofferr	 roff_TS(ROFF_ARGS);
+static	enum rofferr	 roff_EQ(ROFF_ARGS);
+static	enum rofferr	 roff_EN(ROFF_ARGS);
 static	enum rofferr	 roff_T_(ROFF_ARGS);
 static	enum rofferr	 roff_userdef(ROFF_ARGS);
 
@@ -189,6 +196,8 @@ static	struct roffmac	 roffs[ROFF_MAX] = {
 	{ "TS", roff_TS, NULL, NULL, 0, NULL },
 	{ "TE", roff_TE, NULL, NULL, 0, NULL },
 	{ "T&", roff_T_, NULL, NULL, 0, NULL },
+	{ "EQ", roff_EQ, NULL, NULL, 0, NULL },
+	{ "EN", roff_EN, NULL, NULL, 0, NULL },
 	{ ".", roff_cblock, NULL, NULL, 0, NULL },
 	{ "\\}", roff_ccond, NULL, NULL, 0, NULL },
 	{ NULL, roff_userdef, NULL, NULL, 0, NULL },
@@ -311,15 +320,22 @@ static void
 roff_free1(struct roff *r)
 {
 	struct tbl_node	*t;
+	struct eqn_node	*e;
 
-	while (r->first_tbl) {
-		t = r->first_tbl;
+	while (NULL != (t = r->first_tbl)) {
 		r->first_tbl = t->next;
 		tbl_free(t);
 	}
 
 	r->first_tbl = r->last_tbl = r->tbl = NULL;
 
+	while (NULL != (e = r->first_eqn)) {
+		r->first_eqn = e->next;
+		eqn_free(e);
+	}
+
+	r->first_eqn = r->last_eqn = r->eqn = NULL;
+
 	while (r->last)
 		roffnode_pop(r);
 
@@ -477,6 +493,8 @@ roff_parseln(struct roff *r, int ln, char **bufp,
 	 * First, if a scope is open and we're not a macro, pass the
 	 * text through the macro's filter.  If a scope isn't open and
 	 * we're not a macro, just let it through.
+	 * Finally, if there's an equation scope open, divert it into it
+	 * no matter our state.
 	 */
 
 	if (r->last && ! ROFF_CTL((*bufp)[pos])) {
@@ -485,18 +503,26 @@ roff_parseln(struct roff *r, int ln, char **bufp,
 		e = (*roffs[t].text)
 			(r, t, bufp, szp, ln, pos, pos, offs);
 		assert(ROFF_IGN == e || ROFF_CONT == e);
-		if (ROFF_CONT == e && r->tbl)
+		if (ROFF_CONT != e)
+			return(e);
+		if (r->eqn)
+			return(eqn_read(&r->eqn, ln, *bufp, *offs));
+		if (r->tbl)
 			return(tbl_read(r->tbl, ln, *bufp, *offs));
-		return(e);
+		return(ROFF_CONT);
 	} else if ( ! ROFF_CTL((*bufp)[pos])) {
+		if (r->eqn)
+			return(eqn_read(&r->eqn, ln, *bufp, *offs));
 		if (r->tbl)
 			return(tbl_read(r->tbl, ln, *bufp, *offs));
 		return(ROFF_CONT);
-	}
+	} else if (r->eqn)
+		return(eqn_read(&r->eqn, ln, *bufp, *offs));
 
 	/*
 	 * If a scope is open, go to the child handler for that macro,
 	 * as it may want to preprocess before doing anything with it.
+	 * Don't do so if an equation is open.
 	 */
 
 	if (r->last) {
@@ -532,6 +558,13 @@ roff_endparse(struct roff *r)
 		(*r->msg)(MANDOCERR_SCOPEEXIT, r->data,
 				r->last->line, r->last->col, NULL);
 
+	if (r->eqn) {
+		(*r->msg)(MANDOCERR_SCOPEEXIT, r->data, 
+				r->eqn->line, r->eqn->pos, NULL);
+		eqn_end(r->eqn);
+		r->eqn = NULL;
+	}
+
 	if (r->tbl) {
 		(*r->msg)(MANDOCERR_SCOPEEXIT, r->data, 
 				r->tbl->line, r->tbl->pos, NULL);
@@ -1140,6 +1173,33 @@ roff_T_(ROFF_ARGS)
 
 /* ARGSUSED */
 static enum rofferr
+roff_EQ(ROFF_ARGS)
+{
+	struct eqn_node	*e;
+
+	assert(NULL == r->eqn);
+	e = eqn_alloc(ppos, ln);
+
+	if (r->last_eqn)
+		r->last_eqn->next = e;
+	else
+		r->first_eqn = r->last_eqn = e;
+
+	r->eqn = r->last_eqn = e;
+	return(ROFF_IGN);
+}
+
+/* ARGSUSED */
+static enum rofferr
+roff_EN(ROFF_ARGS)
+{
+
+	(*r->msg)(MANDOCERR_NOSCOPE, r->data, ln, ppos, NULL);
+	return(ROFF_IGN);
+}
+
+/* ARGSUSED */
+static enum rofferr
 roff_TS(ROFF_ARGS)
 {
 	struct tbl_node	*t;
@@ -1240,7 +1300,6 @@ roff_userdef(ROFF_ARGS)
 	   ROFF_REPARSE : ROFF_APPEND);
 }
 
-
 static char *
 roff_getname(struct roff *r, char **cpp, int ln, int pos)
 {
@@ -1274,7 +1333,6 @@ roff_getname(struct roff *r, char **cpp, int ln, int pos)
 	return(name);
 }
 
-
 /*
  * Store *string into the user-defined string called *name.
  * In multiline mode, append to an existing entry and append '\n';
@@ -1344,7 +1402,6 @@ roff_setstr(struct roff *r, const char *name, const char *string,
 	*c = '\0';
 }
 
-
 static const char *
 roff_getstrn(const struct roff *r, const char *name, size_t len)
 {
@@ -1357,7 +1414,6 @@ roff_getstrn(const struct roff *r, const char *name, size_t len)
 	return(n ? n->string : NULL);
 }
 
-
 static void
 roff_freestr(struct roff *r)
 {
@@ -1379,3 +1435,10 @@ roff_span(const struct roff *r)
 	
 	return(r->tbl ? tbl_span(r->tbl) : NULL);
 }
+
+const struct eqn *
+roff_eqn(const struct roff *r)
+{
+	
+	return(r->last_eqn ? &r->last_eqn->eqn : NULL);
+}