X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/ba1ecc079bdf04b0fa18d6fcc299374baece7d38..6528a9915199761f9c9887d4152e5196a6c13449:/TODO diff --git a/TODO b/TODO index 168b4e03..5807ccdc 100644 --- a/TODO +++ b/TODO @@ -12,24 +12,21 @@ 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 * Documentation Before releasing, make sure the documentation ("Understanding your parser") refers to the current `output' format. - -* GLR & C++ -Currently, the GLR parser cannot compile with a C++ compiler. - +* lalr1.cc +** vector +Move to using vector, drop stack.hh. * 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. @@ -49,25 +46,11 @@ 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. +** Statically check for potential ambiguities in GLR grammars. See + for an approach. -* 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 -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: - - exp (res): exp (a) '+' exp (b) { $res = $a + $b; }; -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... +* Extensions ** $-1 We should find a means to provide an access to values deep in the @@ -81,33 +64,6 @@ 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 +74,20 @@ 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 @@ -149,23 +119,6 @@ Are there any Texinfo standards for bibliography? * Java, Fortran, etc. -** Java - -There are a couple of proposed outputs: - -- BYACC/J - which is based on Byacc. - - -- Bison Java - which is based on Bison. - - -Sebastien Serrurier (serrur_s@epita.fr) is working on this: he is -expected to contact the authors, design the output, and implement it -into Bison. - - * Coding system independence Paul notes: @@ -179,31 +132,20 @@ 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? +** %token-table +** Skeleton strategy +Must we keep %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 @@ -236,9 +178,6 @@ 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 (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, @@ -318,27 +257,24 @@ at the proper place to bison.simple. Ditto for YYACT_PROLOGUE. 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. +* Better graphics +Equip the parser with a means to create the (visual) parse tree. ----- -Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc. +Copyright (C) 2001-2004, 2006, 2008-2012 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 +This program 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. +the Free Software Foundation, either version 3 of the License, or +(at your option) any later version. -GNU Bison is distributed in the hope that it will be useful, +This program 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. 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