X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/ba1ecc079bdf04b0fa18d6fcc299374baece7d38..5362ed19b6e8a8091345d979eefb4e11087b728f:/TODO diff --git a/TODO b/TODO index 168b4e03..96d5d2a4 100644 --- a/TODO +++ b/TODO @@ -12,24 +12,31 @@ They should not: it is not documented. But if they need to, let's find something clean (not like YYLSP_NEEDED...). -* URGENT: Documenting C++ output -Write a first documentation for C++ output. +* Installation +** Disable installation of yacc. + +Add an option to 'configure' that allows people to install Bison +without installing the yacc wrapper script or the rarely-used little +yacc library required by Posix. This is for people who prefer some +other implementation of yacc. * Documentation Before releasing, make sure the documentation ("Understanding your parser") refers to the current `output' format. +* lalr1.cc +** vector +Move to using vector, drop stack.hh. -* GLR & C++ -Currently, the GLR parser cannot compile with a C++ compiler. - +** I18n +Catch up with yacc.c. * Report ** 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 +what when two reductions are possible on a given lookahead token, but one is part of $default. Should we make the two reductions explicit, or just keep $default? See the following point. @@ -52,14 +59,7 @@ DeRemer and Penello: they already provide the algorithm. * Extensions -** %destructor -I think we should document it as experimental, and allow its use in -the next releases. But we also need to port it to GLR. What about -lalr1.cc? Well, read what Hans reported, maybe we don't want -%detructor. On the other hand, there is no reason not to provide it: -users can avoid its use. - -** $foo +** Labeling the symbols Have a look at the Lemon parser generator: instead of $1, $2 etc. they can name the values. This is much more pleasant. For instance: @@ -69,6 +69,21 @@ I love this. I have been bitten too often by the removal of the symbol, and forgetting to shift all the $n to $n-1. If you are unlucky, it compiles... +But instead of using $a etc., we can use regular variables. And +instead of using (), I propose to use `:' (again). Paul suggests +supporting `->' in addition to `:' to separate LHS and RHS. In other +words: + + r:exp -> a:exp '+' b:exp { r = a + b; }; + +That requires an significant improvement of the grammar parser. Using +GLR would be nice. It also requires that Bison know the type of the +symbols (which will be useful for %include anyway). So we have some +time before... + +Note that there remains the problem of locations: `@r'? + + ** $-1 We should find a means to provide an access to values deep in the stack. For instance, instead of @@ -81,33 +96,6 @@ we should be able to have: Or something like this. - -** yysymprint interface -It should be improved, in particular when using Bison features such as -locations, and YYPARSE_PARAMS. For the time being, it is almost -recommended to 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 -%union. - -When implementing multiple-%union support, bare the following in mind: - -- when --yacc, this must be flagged as an error. Don't make it fatal - though. - -- The #line must now appear *inside* the definition of yystype. - Something like - - { - #line 12 "foo.y" - int ival; - #line 23 "foo.y" - char *sval; - } - ** %if and the like It should be possible to have %if/%else/%endif. The implementation is not clear: should it be lexical or syntactic. Vadim Maslow thinks it @@ -118,6 +106,20 @@ to avoid falling into another CPP mistake. ** -D, --define-muscle NAME=VALUE To define muscles via cli. Or maybe support directly NAME=VALUE? +** XML Output +There are couple of available extensions of Bison targeting some XML +output. Some day we should consider including them. One issue is +that they seem to be quite orthogonal to the parsing technique, and +seem to depend mostly on the possibility to have some code triggered +for each reduction. As a matter of fact, such hooks could also be +used to generate the yydebug traces. Some generic scheme probably +exists in there. + +XML output for GNU Bison and gcc + http://www.cs.may.ie/~jpower/Research/bisonXML/ + +XML output for GNU Bison + http://yaxx.sourceforge.net/ * Unit rules Maybe we could expand unit rules, i.e., transform @@ -179,31 +181,21 @@ Paul notes: PDP-10 ports :-) but they should probably be documented somewhere. - + More importantly, Bison does not currently allow NUL bytes in + tokens, either via escapes (e.g., "x\0y") or via a NUL byte in + the source code. This should get fixed. * --graph -Show reductions. [] +Show reductions. * Broken options ? -** %no-parser [] -** %token-table [] -** Skeleton strategy. [] -Must we keep %no-parser? - %token-table? +** %no-parser +** %token-table +** Skeleton strategy +Must we keep %no-parser? %token-table? * src/print_graph.c -Find the best graph parameters. [] - -* doc/bison.texinfo -** Update -informations about ERROR_VERBOSE. [] -** Add explanations about -skeleton muscles. [] -%skeleton. [] - -* testsuite -** tests/pure-parser.at [] -New tests. +Find the best graph parameters. * BTYacc See if we can integrate backtracking in Bison. Charles-Henri de @@ -324,21 +316,22 @@ the parser with a means to create the (visual) parse tree. ----- -Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc. +Copyright (C) 2001, 2002, 2003, 2004, 2006 Free Software Foundation, +Inc. -This file is part of GNU Bison. +This file is part of Bison, the GNU Compiler Compiler. -GNU Bison is free software; you can redistribute it and/or modify +Bison is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. -GNU Bison is distributed in the hope that it will be useful, +Bison is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Bison; see the file COPYING. If not, write to -the Free Software Foundation, Inc., 59 Temple Place - Suite 330, -Boston, MA 02111-1307, USA. +the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, +Boston, MA 02110-1301, USA.