update.

[bison.git] / TODO

diff --git a/TODO b/TODO
index ea033d1017b2cfd36d70a7fd87b9fdce581cf99f..bc474d21aee7183e7eeada910dd8e17485e51910 100644 (file)
--- a/TODO
+++ b/TODO
@@ -274,39 +274,8 @@ make it much easier to extend the grammar.
 
 * Parsing grammars
 Rewrite the reader in Flex/Bison.  There will be delicate parts, in
-particular, expect the scanner to be hard to write.
-
-* Problems with aliases
-From: "Baum, Nathan I" <s0009525@chelt.ac.uk>
-Subject: Token Alias Bug
-To: "'bug-bison@gnu.org'" <bug-bison@gnu.org>
-
-I've noticed a bug in bison. Sadly, our eternally wise sysadmins won't let
-us use CVS, so I can't find out if it's been fixed already...
-
-Basically, I made a program (in flex) that went through a .y file looking
-for "..."-tokens, and then outputed a %token
-line for it. For single-character ""-tokens, I reasoned, I could just use
-[%token 'A' "A"]. However, this causes Bison to output a [#define 'A' 65],
-which cppp chokes on, not unreasonably. (And even if cppp didn't choke, I
-obviously wouldn't want (char)'A' to be replaced with (int)65 throughout my
-code.
-
-Bison normally forgoes outputing a #define for a character token. However,
-it always outputs an aliased token -- even if the token is an alias for a
-character token. We don't want that. The problem is in /output.c/, as I
-recall. When it outputs the token definitions, it checks for a character
-token, and then checks for an alias token. If the character token check is
-placed after the alias check, then it works correctly.
-
-Alias tokens seem to be something of a kludge. What about an [%alias "..."]
-command...
-
-       %alias T_IF "IF"
-
-Hmm. I can't help thinking... What about a --generate-lex option that
-creates an .l file for the alias tokens used... (Or an option to make a
-gperf file, etc...)
+particular, expect the scanner to be hard to write.  Many interesting
+features cannot be implemented without such a new reader.
 
 * Presentation of the report file
 From: "Baum, Nathan I" <s0009525@chelt.ac.uk>
@@ -355,6 +324,10 @@ them, it is fairly well described there.  It would be very nice to
 implement this in such a way that other programs could use
 lib/warnings.[ch].
 
+Don't work on this without first announcing you do, as I already have
+thought about it, and know many of the components that can be used to
+implement it.
+
 * Pre and post actions.
 From: Florian Krohm <florian@edamail.fishkill.ibm.com>
 Subject: YYACT_EPILOGUE