It does not make a lot of sense to use ::= in our counterexamples,
that's not something that belongs to the Bison "vocabulary". Using
the colon makes sense, but it's too discreet. Let's use the arrow,
which we already use in some reports (HTML and Dot).
* src/gram.h (print_dot_fallback): Generalize into...
(print_fallback): this.
(print_arrow): New.
* src/derivation.c: Use it.
* NEWS, tests/conflicts.at, tests/counterexample.at,
* tests/diagnostics.at, tests/report.at: Adjust.
* doc/bison.texi: Ditto.
Unfortunately the literal `→` is output as `↦`. So we need to use
@arrow.
Prefer `&foos[i]` to `foos + i` when `foos` is an array. IMHO, it
makes the semantics clearer.
* src/counterexample.c, src/lssi.c, src/parse-simulation.c,
* src/state-item.c: With arrays, prefer the array notation rather than
the pointer one.
* examples/c/bistromathic/parse.y (user_context): We need the current
line.
(yyreport_syntax_error): Quote the guilty line, with squiggles.
* examples/c/bistromathic/bistromathic.test: Adjust.
Currently autocompletion on a line with errors leaks the error
messages. It can be useful to let the user know, but GNU Readline
does not provide us with an nice way to display the error. So we
actually break into the current line of the user.
So instead, do not show these errors.
* examples/c/bistromathic/parse.y (user_context): New.
Use %param to pass it to the parser and scanner.
Keep quiet when in computing autocompletion.
That quite defeats the whole point of locations... But anyway, we
should not see these messages at all.
* examples/c/bistromathic/parse.y (expected_tokens): Fix (useless)
location tracking.
Currently when we output useless rules, they appear before the
grammar, but using the same invocation. As a result, the anchor is
defined twice, and the wrong one, being first, is honored.
* data/xslt/xml2xhtml.xsl (rule): Take a new 'anchor' parameter to
decide whether being an anchor, or a target.
Let it be true when output the grammar.
* tests/report.at: Adjust.
The text and Dot reports are expected to be identical when generated
directly (--report, --graph) or indirectly (via XML). The xml
testsuite had not be run for ages, let it catch up a bit.
* src/print-xml.c: Pass the type of the symbols.
* data/xslt/xml2text.xsl
Catch up with the new layout.
Display the symbol types.
Use '•', not '.'
* tests/local.at: Smash '•' to '.' when matching against the direct
text report.
* tests/report.at: Adjust XML expectations.
* data/skeletons/c++.m4, data/skeletons/glr.c, data/skeletons/lalr1.d,
* data/skeletons/lalr1.java, data/skeletons/yacc.c:
Be more accurate about yychar and yytoken.
Don't name local variables as if they were members.
* examples/c/bistromathic/parse.y, examples/c/lexcalc/parse.y,
* examples/c/reccalc/parse.y: here.
Add some comments.
* src/parse-gram.y (api_version): Pull out of handle_require.
Bump to 3.7.
* data/bison-default.css: Cobalt does not seem to be supported.
* doc/bison.texi (Counterexamples): A new section.
(Understanding): Show the counterexamples as it shows in the report:
with its items.
(Bison Options): Document -Wcex and -rcex.
In commit c80cdf2db2 ("doc: simplify
uses of @ref", Jan 27 2020, released in Bison 3.6), I broke the
references to the Bibliography. For instance:
For a more detailed exposition of the mysterious behavior in LALR parsers
-and the benefits of IELR, @pxref{Bibliography,,Denny 2008 March}, and
-@ref{Bibliography,,Denny 2010 November}.
+and the benefits of IELR, @pxref{Bibliography}, and
+@ref{Bibliography}.
which results in "see Bibliography" twice, instead of the more precise
reference.
* doc/bison.texi (@pcite, @tcite): New.
Use them instead of @ref to Bibliography.
Cite only the first author (that's what we did for the other entries).
Currently when a push parser finishes its parsing (i.e., it did not
return YYPUSH_MORE), it also clears its state. It is therefore
impossible to see if it had parse errors.
In the context of autocompletion, because error recovery might have
fired, the parser is actually already in a different state. For
instance on `(1 + + <TAB>` in the bistromathic, because there's a
`exp: "(" error ")"` recovery rule, `1 + +` tokens have already been
popped, replaced by `error`, and autocompletions think we are ready
for the closing ")". So here, we would like to see if there was a
syntax error, yet `yynerrs` was cleared.
In the case of a successful parse, we still have a problem: if error
recovery succeeded, we won't know it, since, again, `yynerrs` is
clearer.
It seems much more natural to leave the parser state available for
analysis when there is a failure.
To reuse the parser, we should either:
1. provide an explicit means to reinitialize a parser state for future
parses.
2. automatically reset the parser state when it is used in a new
parse.
Option 2 requires to check whether we need to reinitialize the parser
each time we call `yypush_parse`, i.e., each time we give a new token.
This seems expensive compared to Option 1, but benchmarks revealed no
difference. Option 1 is incompatible with the documentation
("After `yypush_parse` returns a status other than `YYPUSH_MORE`, the
parser instance `yyps` may be reused for a new parse.").
So Option 2 wins, reusing the private `yynew` member to record that a
parse was finished, and therefore that the state must reset in the
next call to `yypull_parse`.
While at it, this implementation now reuses the previously enlarged
stacks from one parse to another.
* data/skeletons/yacc.c (yypstate_new): Set up the stacks in their
initial configurations (setting their bottom to the stack array), and
use yypstate_clear to reset them (moving their top to their bottom).
(yypstate_delete): Adjust.
(yypush_parse): At the beginning, clear yypstate if needed, and at the
end, record when yypstate needs to be clearer.
* examples/c/bistromathic/parse.y (expected_tokens): Do not propose
autocompletion when there are parse errors.
* examples/c/bistromathic/bistromathic.test: Check that case.
Currently, completion when there is a syntax error shows broken
locations.
* examples/c/bistromathic/parse.y (expected_tokens): Initialize the
location.
* examples/c/bistromathic/bistromathic.test: Check that.
The previous commit ("yacc.c: declare and initialize and the same
time") made b4_initialize_parser_state_variables useless.
* data/skeletons/yacc.c (b4_initialize_parser_state_variables): Inline
into...
(yypstate_clear): here.
In order to factor the code of push and pull parsers, the declaration
of the parser's state variable was common (being local variable in
pull parsers, and struct members in push parsers). This result in
rather poor style in pull parser, with first variable declarations,
and then their initializations.
The initialization is about to differ between push and pull parsers,
so it is no longer worth keeping both cases together.
* data/skeletons/yacc.c (b4_declare_parser_state_variables): Accept an
argument, and when it is set, initialize the variables.
Adjust dependencies.
Currently yypull_parse takes a yypstate* as argument, and accepts it
to be NULL. This does not seem to make a lot of sense: rather it is
its callers that should do that.
I believe this is historical: yypull_parse was introduced
first (c3d503425f), with yyparse being a
macro. So yyparse could hardly deal with memory allocation properly.
In 7172e23e8f that yyparse was turned
into a genuine function. At that point, it should have allocated its
own yypstate*, which would have left yypull_parse deal with only one
single non-null ypstate* argument.
Fortunately, it is nowhere documented that it is valid to pass NULL to
yypull_parse. It is now forbidden.
* data/skeletons/yacc.c (yypull_parse): Don't allocate a yypstate.
Needs a location to issue the error message.
(yyparse): Allocate the yypstate.
