[PATCH] todo: update

[Theophile Ranquet]

Reformulate and give more details on my thoughts concerning the graphical
visualization, and add an entry about a bug in the options processing for
warnings as errors.

* TODO: Here.
---
 TODO | 54 ++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 44 insertions(+), 10 deletions(-)

diff --git a/TODO b/TODO
index 18c8999..d2e457c 100644
--- a/TODO
+++ b/TODO
@@ -1,16 +1,50 @@
 * Short term
+** Laxism in Bison invocation arguments:
+The flag_argmatch functions were meant to be generic. The introduction of
+-Werror= in generic code is a bit troublesome, and generates weird
+behaviour. Because seeing "error=" causes Bison to match the subsequent
+categories with a generic procedure, but on a very specific variable, the
+following commands are legal, and equivalent:
+
+$ bison -Werror=yacc            # OK
+$ bison --warnings=error=yacc   # err, looks very weird?
+$ bison -rerror=itemsets        # this value of 'report' enum has a value
+                                # of '1 << 1', just like Wyacc
+$ bison --report=error=itemsets # (same)
+$ bison -ferror=caret           # (same)
+$ bison --feature=error=caret   # (same)
+
+Basically, writing -rerror={THINGS} or -ferror={FEATURE} is not prohibited,
+and results in UB.
+
+I don't think there is any reason for the user to expect anything out of
+these options (this implementation-driven behavior is not documented of
+course, as it isn't exactly a feature), so this bug isn't critical but
+should be addressed some day nonetheless.
+
 ** Graphviz display code thoughts
 The code for the --graph option is over two files: print_graph, and
-graphviz. I believe this is because Bison used to also produce VCG graphs,
-but since this is no longer true, maybe we could consider these files for
-fusion.
-
-Little effort factoring seems to have been given to factoring in these files,
-and their print-xml and print counterpart. We would very much like to re-use
-the pretty format of states from .output in the .dot
-
-Also, the underscore in print_graph.[ch] isn't very fitting considering
-the dashes in the other filenames.
+graphviz. This is because Bison used to also produce VCG graphs, but since
+this is no longer true, maybe we could consider these files for fusion.
+
+An other consideration worth noting is that print_graph.c (correct me if I
+am wrong) should contain generic functions, whereas graphviz.c and other
+potential files should contain just the specific code for that output
+format. It will probably prove difficult to tell if the implementation is
+actually generic whilst only having support for a single format, but it
+would be nice to keep stuff a bit tidier: right now, the construction of the
+bitset used to show reductions is in the graphviz-specific code, and on the
+opposite side we have some use of \l, which is graphviz-specific, in what
+should be generic code.
+
+Little effort seems to have been given to factoring these files and their
+rint{,-xml} counterpart. We would very much like to re-use the pretty format
+of states from .output for the graphs, etc.
+
+Also, the underscore in print_graph.[ch] isn't very fitting considering the
+dashes in the other filenames.
+
+Since graphviz dies on medium-to-big grammars, maybe consider an other tool?
 
 ** push-parser
 Check it too when checking the different kinds of parsers.  And be
-- 
1.8.1.2