* URGENT: Documenting C++ output
Write a first documentation for C++ output.
-* Report and GLR
-How would Paul like to display the conflicted actions? In particular,
-what when two reductions are possible on a given lookahead, but one is
-part of $default. Should we make the two reductions explicit, or just
-keep $default? See the following point.
-* Report and Disabled Reductions
-See `tests/conflicts.at (Defaulted Conflicted Reduction)', and decide
-what we want to do.
+* Documentation
+Before releasing, make sure the documentation refers to the current
+`output' format.
+
+
+* Error messages
+Some are really funky. For instance
+
+ type clash (`%s' `%s') on default action
+
+is really weird. Revisit them all.
+
+* Stupid error messages
+An example shows it easily:
+
+src/bison/tests % ./testsuite -k calc,location,error-verbose -l
+GNU Bison 1.49a test suite test groups:
+
+ NUM: FILENAME:LINE TEST-GROUP-NAME
+ KEYWORDS
+
+ 51: calc.at:440 Calculator --locations --yyerror-verbose
+ 52: calc.at:442 Calculator --defines --locations --name-prefix=calc --verbose --yacc --yyerror-verbose
+ 54: calc.at:445 Calculator --debug --defines --locations --name-prefix=calc --verbose --yacc --yyerror-verbose
+src/bison/tests % ./testsuite 51 -d
+## --------------------------- ##
+## GNU Bison 1.49a test suite. ##
+## --------------------------- ##
+ 51: calc.at:440 ok
+## ---------------------------- ##
+## All 1 tests were successful. ##
+## ---------------------------- ##
+src/bison/tests % cd ./testsuite.dir/51
+tests/testsuite.dir/51 % echo "()" | ./calc
+1.2-1.3: parse error, unexpected ')', expecting error or "number" or '-' or '('
+
+
+* read_pipe.c
+This is not portable to DOS for instance. Implement a more portable
+scheme. Sources of inspiration include GNU diff, and Free Recode.
+
* value_components_used
Was defined but not used: where was it coming from? It can't be to
check if %union is used, since the user is free to $<foo>n on her
union, doesn't she?
-* yyerror, yyprint interface
-It should be improved, in particular when using Bison features such as
-locations, and YYPARSE_PARAMS. For the time being, it is recommended
-to #define yyerror and yyprint to steal internal variables...
-
-* documentation
-Explain $axiom (and maybe change its name: BTYacc names it `goal',
-byacc `$accept' probably based on AT&T Yacc, Meta `Start'...).
-Complete the glossary (item, axiom, ?). Should we also rename `$'?
-BYacc uses `$end'. `$eof' is attracting, but after all we may be
-parsing a string, a stream etc.
-* Error messages
-Some are really funky. For instance
+* Report
- type clash (`%s' `%s') on default action
+** GLR
+How would Paul like to display the conflicted actions? In particular,
+what when two reductions are possible on a given lookahead, but one is
+part of $default. Should we make the two reductions explicit, or just
+keep $default? See the following point.
-is really weird. Revisit them all.
+** Disabled Reductions
+See `tests/conflicts.at (Defaulted Conflicted Reduction)', and decide
+what we want to do.
-* Report documentation
+** Documentation
Extend with error productions. The hard part will probably be finding
the right rule so that a single state does not exhibit too 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
-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. See the paper from
+DeRemer and Penello: they already provide the algorithm.
+
+
+* Extentions
-* Several %unions
+** yyerror, yysymprint interface
+It should be improved, in particular when using Bison features such as
+locations, and YYPARSE_PARAMS. For the time being, it is recommended
+to #define yyerror and yyprint to steal internal variables...
+
+** Several %unions
I think this is a pleasant (but useless currently) feature, but in the
future, I want a means to %include other bits of grammars, and _then_
it will be important for the various bits to define their needs in
char *sval;
}
-* --report=conflict-path
-Provide better assistance for understanding the conflicts by providing
-a sample text exhibiting the (LALR) ambiguity. See the paper from
-DeRemer and Penello: they already provide the algorithm.
-
-* Coding system independence
-Paul notes:
-
- Currently Bison assumes 8-bit bytes (i.e. that UCHAR_MAX is
- 255). It also assumes that the 8-bit character encoding is
- the same for the invocation of 'bison' as it is for the
- invocation of 'cc', but this is not necessarily true when
- people run bison on an ASCII host and then use cc on an EBCDIC
- host. I don't think these topics are worth our time
- addressing (unless we find a gung-ho volunteer for EBCDIC or
- PDP-10 ports :-) but they should probably be documented
- somewhere.
-
* Unit rules
Maybe we could expand unit rules, i.e., transform
`Parsing Techniques: a Practical Guide', it includes information about
this issue. Does anybody have it?
-* Stupid error messages
-An example shows it easily:
-src/bison/tests % ./testsuite -k calc,location,error-verbose -l
-GNU Bison 1.49a test suite test groups:
- NUM: FILENAME:LINE TEST-GROUP-NAME
- KEYWORDS
+* Documentation
- 51: calc.at:440 Calculator --locations --yyerror-verbose
- 52: calc.at:442 Calculator --defines --locations --name-prefix=calc --verbose --yacc --yyerror-verbose
- 54: calc.at:445 Calculator --debug --defines --locations --name-prefix=calc --verbose --yacc --yyerror-verbose
-src/bison/tests % ./testsuite 51 -d
-## --------------------------- ##
-## GNU Bison 1.49a test suite. ##
-## --------------------------- ##
- 51: calc.at:440 ok
-## ---------------------------- ##
-## All 1 tests were successful. ##
-## ---------------------------- ##
-src/bison/tests % cd ./testsuite.dir/51
-tests/testsuite.dir/51 % echo "()" | ./calc
-1.2-1.3: parse error, unexpected ')', expecting error or "number" or '-' or '('
+** History/Bibliography
+Some history of Bison and some bibliography would be most welcome.
+Are there any Texinfo standards for bibliography?
+
+
+
+
+* Coding system independence
+Paul notes:
+
+ Currently Bison assumes 8-bit bytes (i.e. that UCHAR_MAX is
+ 255). It also assumes that the 8-bit character encoding is
+ the same for the invocation of 'bison' as it is for the
+ invocation of 'cc', but this is not necessarily true when
+ people run bison on an ASCII host and then use cc on an EBCDIC
+ host. I don't think these topics are worth our time
+ addressing (unless we find a gung-ho volunteer for EBCDIC or
+ PDP-10 ports :-) but they should probably be documented
+ somewhere.
-* read_pipe.c
-This is not portable to DOS for instance. Implement a more portable
-scheme. Sources of inspiration include GNU diff, and Free Recode.
-* Memory leaks in the generator
-A round of memory leak clean ups would be most welcome. Dmalloc,
-Checker GCC, Electric Fence, or Valgrind: you chose your tool.
* --graph
Show reductions. []
See if we can integrate backtracking in Bison. Contact the BTYacc
maintainers.
-* RR conflicts
-See if we can use precedence between rules to solve RR conflicts. See
-what POSIX says.
+** Keeping the conflicted actions
+First, analyze the differences between byacc and btyacc (I'm referring
+to the executables). Find where the conflicts are preserved.
+
+** Compare with the GLR tables
+See how isomorphic the way BTYacc and the way the GLR adjustements in
+Bison are compatible. *As much as possible* one should try to use the
+same implementation in the Bison executables. I insist: it should be
+very feasible to use the very same conflict tables.
+
+** Adjust the skeletons
+Import the skeletons for C and C++.
+
+** Improve the skeletons
+Have them support yysymprint, yydestruct and so forth.
+
* Precedence
+
+** Partial order
It is unfortunate that there is a total order for precedence. It
makes it impossible to have modular precedence information. We should
-move to partial orders.
+move to partial orders (sounds like series/parallel orders to me).
This will be possible with a Bison parser for the grammar, as it will
make it much easier to extend the grammar.
+** Correlation b/w precedence and associativity
+Also, I fail to understand why we have to assign the same
+associativity to operators with the same precedence. For instance,
+why can't I decide that the precedence of * and / is the same, but the
+latter is nonassoc?
+
+If there is really no profound motivation, we should find a new syntax
+to allow specifying this.
+
+** RR conflicts
+See if we can use precedence between rules to solve RR conflicts. See
+what POSIX says.
+
+
* $undefined
From Hans:
- If the Bison generated parser experiences an undefined number in the
Suggest: Change the name $undefined to undefined; looks better in outputs.
+
* Default Action
From Hans:
- For use with my C++ parser, I transported the "switch (yyn)" statement
Note: Robert Anisko handles this. He knows how to do it.
+
* Warnings
It would be nice to have warning support. See how Autoconf handles
them, it is fairly well described there. It would be very nice to
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
projects / bison.git / blobdiff