X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/90462b8dd909d36e8c0b7d672238e9e385a3ba8d..ba60c39547a445dee3e07920931b4d7a81843868:/TODO diff --git a/TODO b/TODO index 376ec1d7..f3bcf19d 100644 --- a/TODO +++ b/TODO @@ -1,6 +1,28 @@ -*- outline -*- * Short term +** Use syntax_error from the scanner? +This would provide a means to raise syntax error from function called +from the scanner. Actually, there is no good solution to report a +lexical error in general. Usually they are kept at the scanner level +only, ignoring the guilty token. But that might not be the best bet, +since we don't benefit from the syntactic error recovery. + +We still have the possibility to return an invalid token number, which +does the trick. But then the error message from the parser is poor +(something like "unexpected $undefined"). Since the scanner probably +already reported the error, we should directly enter error-recovery, +without reporting the error message (i.e., YYERROR's semantics). + +Back to lalr1.cc (whose name is now quite unfortunate, since it also +covers lr and ielr), if we support exceptions from yylex, should we +propose a lexical_error in addition to syntax_error? Should they have +a common root, say parse_error? Should syntax_error be renamed +syntactic_error for consistency with lexical_error? + +** Variable names. +What should we name `variant' and `lex_symbol'? + ** Use b4_symbol in all the skeleton Then remove the older system, including the tables generated by output.c @@ -194,6 +216,13 @@ parser") refers to the current `output' format. * Report +** Figures +Some statistics about the grammar and the parser would be useful, +especially when asking the user to send some information about the +grammars she is working on. We should probably also include some +information about the variables (I'm not sure for instance we even +specify what LR variant was used). + ** GLR How would Paul like to display the conflicted actions? In particular, what when two reductions are possible on a given lookahead token, but one is @@ -426,10 +455,26 @@ to bison. If you're interested, I'll work on a patch. * Better graphics Equip the parser with a means to create the (visual) parse tree. +* Complaint submessage indentation. +We already have an implementation that works fairly well for named +reference messages, but it would be nice to use it consistently for all +submessages from Bison. For example, the "previous definition" +submessage or the list of correct values for a %define variable might +look better with indentation. + +However, the current implementation makes the assumption that the +location printed on the first line is not usually much shorter than the +locations printed on the submessage lines that follow. That assumption +may not hold true as often for some kinds of submessages especially if +we ever support multiple grammar files. + +Here's a proposal for how a new implementation might look: + + http://lists.gnu.org/archive/html/bison-patches/2009-09/msg00086.html + ----- -Copyright (C) 2001, 2002, 2003, 2004, 2006, 2008 Free Software Foundation, -Inc. +Copyright (C) 2001-2004, 2006, 2008-2011 Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler.