Re: eqn(7) doesn't distinguish mathematical words

[Ingo Schwarze <schwarze@usta.de>]

Hi Anthony,

Anthony J. Bentley wrote on Mon, Jun 19, 2017 at 10:36:43PM -0600:

> From the Plan 9 eqn(1) manual:
> "Mathematical words like sin, cos, log are made Roman automatically."

That was already addressed earlier.

> The exception proves the rule, which is that eqn(1) italicizes words
> in general.
> 
> .EQ
> a ab sin
> .EN
> 
> In groff and Heirloom, the above results in italic a and ab, and
> roman sin.

Fixed for the terminal formatter by the commit appended below.

> In mandoc -Thtml, it instead results in italic a, and roman
> ab and sin.

Improving HTML output is still an open task.

Yours,
  Ingo


Log Message:
-----------
Fix font selection for text boxes in the terminal formatter.
Issue reported by bentley@.

The AST data structure is powerful enough that all required 
information can easily be provided in the parser, and no change
of the formatting code is needed.

Modified Files:
--------------
    mdocml:
        eqn.c

Revision Data
-------------
Index: eqn.c
===================================================================
RCS file: /home/cvs/mdocml/mdocml/eqn.c,v
retrieving revision 1.66
retrieving revision 1.67
diff -Leqn.c -Leqn.c -u -p -r1.66 -r1.67
--- eqn.c
+++ eqn.c
@@ -84,6 +84,8 @@ enum	eqn_tok {
 	EQN_TOK_ABOVE,
 	EQN_TOK__MAX,
 	EQN_TOK_FUNC,
+	EQN_TOK_QUOTED,
+	EQN_TOK_SYM,
 	EQN_TOK_EOF
 };
 
@@ -517,7 +519,7 @@ eqn_tok_parse(struct eqn_node *ep, char 
 	if (quoted) {
 		if (p != NULL)
 			*p = mandoc_strndup(start, sz);
-		return EQN_TOK__MAX;
+		return EQN_TOK_QUOTED;
 	}
 
 	for (i = 0; i < EQN_TOK__MAX; i++)
@@ -528,7 +530,7 @@ eqn_tok_parse(struct eqn_node *ep, char 
 		if (STRNEQ(start, sz,
 		    eqnsyms[i].str, strlen(eqnsyms[i].str))) {
 			mandoc_asprintf(p, "\\[%s]", eqnsyms[i].sym);
-			return EQN_TOK__MAX;
+			return EQN_TOK_SYM;
 		}
 	}
 
@@ -1084,8 +1086,10 @@ this_tok:
 		 * TODO: make sure we're not in an open subexpression.
 		 */
 		return ROFF_EQN;
-	case EQN_TOK_FUNC:
 	case EQN_TOK__MAX:
+	case EQN_TOK_FUNC:
+	case EQN_TOK_QUOTED:
+	case EQN_TOK_SYM:
 		assert(p != NULL);
 		/*
 		 * If we already have something in the stack and we're
@@ -1112,17 +1116,27 @@ this_tok:
 		cur->text = p;
 		/*
 		 * If not inside any explicit font context,
-		 * give every letter its own box.
+		 * quoted strings become italic, and every letter
+		 * of a bare string gets its own italic box.
 		 */
-		if (fontp == NULL && *p != '\0') {
+		do {
+			if (fontp != NULL || *p == '\0' ||
+			    tok == EQN_TOK_SYM)
+				break;
+			if (tok == EQN_TOK_QUOTED) {
+				cur->font = EQNFONT_ITALIC;
+				break;
+			}
 			cp = p;
 			for (;;) {
+				if (isalpha((unsigned char)*cp))
+					cur->font = EQNFONT_ITALIC;
 				cpn = cp + 1;
 				if (*cp == '\\')
 					mandoc_escape(&cpn, NULL, NULL);
 				if (*cpn == '\0')
 					break;
-				if (isalpha((unsigned char)*cp) == 0 &&
+				if (cur->font != EQNFONT_ITALIC &&
 				    isalpha((unsigned char)*cpn) == 0) {
 					cp = cpn;
 					continue;
@@ -1137,7 +1151,7 @@ this_tok:
 				cur = nbox;
 				cp = nbox->text;
 			}
-		}
+		} while (0);
 		/*
 		 * Post-process list status.
 		 */
--
 To unsubscribe send an email to tech+unsubscribe@mdocml.bsd.lv