Parse errors lose program prefix and parens.

* parser.l (yyerrorf): Don't print the program prefix
and parenthes, except if compatibility to 114 or older is
requested. The main motivation for this is the repl, where the
program prefix is not informative.  The new format is also a
de facto standard which is compatible with other parsers.
Vim understands it directly.

* txr.1: Documented.

1 files changed, 7 insertions, 2 deletions

diff --git a/parser.l b/parser.l
index 6d6fca08..087a3db4 100644
--- a/parser.l
+++ b/parser.l
@@ -108,8 +108,13 @@ void yyerrorf(scanner_t *scanner, val fmt, ...)
   if (opt_loglevel >= 1) {
     va_list vl;
     va_start (vl, fmt);
-    format(std_error, lit("~a: (~a:~a): "), prog_string,
-           parser->name, num(parser->lineno), nao);
+    if (opt_compat && opt_compat <= 114)
+      format(std_error, lit("~a: (~a:~a): "), prog_string,
+             parser->name, num(parser->lineno), nao);
+    else
+      format(std_error, lit("~a:~a: "),
+             parser->name, num(parser->lineno), nao);
+
     vformat(std_error, fmt, vl);
     put_char(chr('\n'), std_error);
     va_end (vl);