--- a/src/Pure/Syntax/syn_ext.ML Tue Nov 19 13:20:38 1996 +0100
+++ b/src/Pure/Syntax/syn_ext.ML Tue Nov 19 13:21:02 1996 +0100
@@ -190,10 +190,8 @@
let
val (ch_name, cs') = (scan_id -- $$ "}" >> #1) cs
handle LEXICAL_ERROR => err "malformed symbolic char specification";
- val c =
- if ch_name mem SymbolFont.char_names then
- SymbolFont.char ch_name
- else err ("unknown symbolic char name: " ^ quote ch_name);
+ val c = the (SymbolFont.char ch_name)
+ handle OPTION _ => err ("unknown symbolic char name: " ^ quote ch_name);
in (c, cs') end
| scan_delim_char (chs as c :: cs) =
if is_blank c orelse is_meta c then raise LEXICAL_ERROR else (c, cs)