* documentation
Explain $axiom (and maybe change its name: BTYacc names it `goal',
-byacc `$accept', probably based on AT&T Yacc). Complete the glossary
-(item, axiom, ?).
+byacc `$accept' probably based on AT&T Yacc, Meta `Start'...).
+Complete the glossary (item, axiom, ?).
-* report documentation
+* Error messages
+Some are really funky. For instance
+
+ type clash (`%s' `%s') on default action
+
+is really weird. Revisit them all.
+
+* Report documentation
Extend with error. The hard part will probably be finding the right
rule so that a single state does not exhibit to many yet undocumented
``features''. Maybe an empty action ought to be presented too. Shall
we try to make a single grammar with all these features, or should we
have several very small grammars?
-* documentation
+* Documentation
Some history of Bison and some bibliography would be most welcome.
Are there any Texinfo standards for bibliography?
* --report=conflict-path
Provide better assistance for understanding the conflicts by providing
-a sample text exhibiting the (LALR) ambiguity.
+a sample text exhibiting the (LALR) ambiguity. See the paper from
+DeRemer and Penello: they already provide the algorithm.
* Coding system independence
Paul notes:
PDP-10 ports :-) but they should probably be documented
somewhere.
-* Output directory
-Akim:
-
-| I consider this to be a bug in bison:
-|
-| /tmp % mkdir src
-| /tmp % cp ~/src/bison/tests/calc.y src
-| /tmp % mkdir build && cd build
-| /tmp/build % bison ../src/calc.y
-| /tmp/build % cd ..
-| /tmp % ls -l build src
-| build:
-| total 0
-|
-| src:
-| total 32
-| -rw-r--r-- 1 akim lrde 27553 oct 2 16:31 calc.tab.c
-| -rw-r--r-- 1 akim lrde 3335 oct 2 16:31 calc.y
-|
-|
-| Would it be safe to change this behavior to something more reasonable?
-| Do you think some people depend upon this?
-
-Jim:
-
-Is it that behavior documented?
-If so, then it's probably not reasonable to change it.
-I've Cc'd the automake list, because some of automake's
-rules use bison through $(YACC) -- though I'll bet they
-all use it in yacc-compatible mode.
-
-Pavel:
-
-Hello, Jim and others!
-
-> Is it that behavior documented?
-> If so, then it's probably not reasonable to change it.
-> I've Cc'd the automake list, because some of automake's
-> rules use bison through $(YACC) -- though I'll bet they
-> all use it in yacc-compatible mode.
-
-Yes, Automake currently used bison in Automake-compatible mode, but it
-would be fair for Automake to switch to the native mode as long as the
-processed files are distributed and "missing" emulates bison.
-
-In any case, the makefiles should specify the output file explicitly
-instead of relying on weird defaults.
-
-> | src:
-> | total 32
-> | -rw-r--r-- 1 akim lrde 27553 oct 2 16:31 calc.tab.c
-> | -rw-r--r-- 1 akim lrde 3335 oct 2 16:31 calc.y
-
-This is not _that_ ugly as it seems - with Automake you want to put
-sources where they belong - to the source directory.
-
-> | This is not _that_ ugly as it seems - with Automake you want to put
-> | sources where they belong - to the source directory.
->
-> The difference source/build you are referring to is based on Automake
-> concepts. They have no sense at all for tools such as bison or gcc
-> etc. They have input and output. I do not want them to try to grasp
-> source/build. I want them to behave uniformly: output *here*.
-
-I realize that.
-
-It's unfortunate that the native mode of Bison behaves in a less uniform
-way than the yacc mode. I agree with your point. Bison maintainters may
-want to fix it along with the documentation.
-
-
* Unit rules
Maybe we could expand unit rules, i.e., transform
exp: exp '+' exp | exp '&' exp;
when there are no actions. This can significantly speed up some
-grammars.
+grammars. I can't find the papers. In particular the book `LR
+parsing: Theory and Practice' is impossible to find, but according to
+`Parsing Techniques: a Practical Guide', it includes information about
+this issue. Does anybody have it?
* Stupid error messages
An example shows it easily:
A round of memory leak clean ups would be most welcome. Dmalloc,
Checker GCC, Electric Fence, or Valgrind: you chose your tool.
-* Memory leaks in the parser
-The same applies to the generated parsers. In particular, this is
-critical for user data: when aborting a parsing, when handling the
-error token etc., we often throw away yylval without giving a chance
-of cleaning it up to the user.
-
* --graph
Show reductions. []
See if we can integrate backtracking in Bison. Contact the BTYacc
maintainers.
-* Automaton report
-Display more clearly the lookaheads for each item.
-
* RR conflicts
See if we can use precedence between rules to solve RR conflicts. See
what POSIX says.
This will be possible with a Bison parser for the grammar, as it will
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. Many interesting
-features cannot be implemented without such a new reader.
-
* $undefined
From Hans:
- If the Bison generated parser experiences an undefined number in the
I was wondering what you think about adding YYACT_PROLOGUE/EPILOGUE
to bison. If you're interested, I'll work on a patch.
+* Move to Graphviz
+Well, VCG seems really dead. Move to Graphviz instead. Also, equip
+the parser with a means to create the (visual) parse tree.
+
-----
Copyright (C) 2001, 2002 Free Software Foundation, Inc.
projects / bison.git / blobdiff