TODO: update

This commit is contained in:
Akim Demaille
2018-11-26 20:21:09 +01:00
parent 9476783307
commit 4ad877fdab

45
TODO
View File

@@ -1,3 +1,11 @@
* Completion
Several features are not available in all the backends.
- push parsers: glr.cc, lalr1.cc
- ielr: C++ and Java
- glr: Java
- token constructors: Java and C
* Short term
** yacc.c
Now that ylwrap is fixed, we should include foo.tab.h from foo.tab.c rather
@@ -70,11 +78,6 @@ back-ported.
yytoken = yytranslate_ (yychar);
** stack.hh
Get rid of it. The original idea is nice, but actually it makes
the code harder to follow, and uselessly different from the other
skeletons.
** Get rid of fake #lines [Bison: ...]
Possibly as simple as checking whether the column number is nonnegative.
@@ -277,7 +280,9 @@ https://lists.gnu.org/archive/html/bug-bison/2016-06/msg00000.html
http://www.cs.cornell.edu/andru/papers/cupex/
* Unit rules
Maybe we could expand unit rules, i.e., transform
Maybe we could expand unit rules (or "injections", see
https://homepages.cwi.nl/~daybuild/daily-books/syntax/2-sdf/sdf.html), i.e.,
transform
exp: arith | bool;
arith: exp '+' exp;
@@ -287,11 +292,11 @@ into
exp: exp '+' exp | exp '&' exp;
when there are no actions. This can significantly speed up some
grammars. I can't find the papers. In particular the book 'LR
parsing: Theory and Practice' is impossible to find, but according to
'Parsing Techniques: a Practical Guide', it includes information about
this issue. Does anybody have it?
when there are no actions. This can significantly speed up some grammars.
I can't find the papers. In particular the book 'LR parsing: Theory and
Practice' is impossible to find, but according to 'Parsing Techniques: a
Practical Guide', it includes information about this issue. Does anybody
have it?
@@ -330,10 +335,6 @@ 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).
** RR conflicts
See if we can use precedence between rules to solve RR conflicts. See
what POSIX says.
* $undefined
From Hans:
@@ -344,20 +345,6 @@ addition to the $undefined value.
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
that Bison writes to the bison.simple skeleton file. This way, I can remove
the current default rule $$ = $1 implementation, which causes a double
assignment to $$ which may not be OK under C++, replacing it with a
"default:" part within the switch statement.
Note that the default rule $$ = $1, when typed, is perfectly OK under C,
but in the C++ implementation I made, this rule is different from
$<type_name>$ = $<type_name>1. I therefore think that one should implement
a Bison option where every typed default rule is explicitly written out
(same typed ruled can of course be grouped together).
* Pre and post actions.
From: Florian Krohm <florian@edamail.fishkill.ibm.com>
Subject: YYACT_EPILOGUE