how to get left hand side symbol in action
Hi All,
Is it possible in *any* way to get the left hand side symbol in an action of a
rule? Say, I have:
A : B C
{
std:cout<<"left hand side symbol is:"
Re: Bison + Flex on C++ don't work
Maybe related? /usr/local$ find . | grep -i bison | grep -i lib ./Cellar/bison/3.1/lib ./Cellar/bison/3.1/lib/liby.a [...] I miss the dynamic version but 🤷♀️ Cheers, Sent from my iPhone > On 6 May 2019, at 02:37, Joao Pedro Abreu De Souza wrote: > > Hi folks. My friend Nicholas and I are trying to make a compiler for a > simpler language(just expressions by now) with flex and bison using C++. > > Using > https://www.gnu.org/software/bison/manual/html_node/A-Complete-C_002b_002b-Example.html > as a guide, we code the repository below, but when We try > > bison -d parser.yy -o parser.cc > lex scanner.l > g++ lex.yy.cc parser.cc main.cc -o cppimp > > > Give us the error in the file > > repository : https://github.com/nicholas-barcelos/Cppimp > > We try to change headers of place, move definitions of class, but nothing > work. What are we making wrong? Thanks in advance > > ___ > help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison ___ help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison
Re: how to get left hand side symbol in action
Hi,
you refer to the left-hand side with $$. Provided it has a 'printable'
type (int, char *, string), it should output.
BR,
Giacinto
On Mon, May 6, 2019 at 11:28 AM r0ller wrote:
>
> Hi All,
>
> Is it possible in *any* way to get the left hand side symbol in an action of
> a rule? Say, I have:
>
> A : B C
> {
> std:cout<<"left hand side symbol is:"< };
>
> I tried to find it out myself and googled a lot but didn't find anything:(
>
> Best regards,
> r0ller
> ___
> help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison
___
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Re: how to get left hand side symbol in action
I thought they mean the [non terminal] **symbol**,
instead of the actual object?
Regards,
> On 6 May 2019, at 14:27, Giacinto Cifelli wrote:
>
> Hi,
>
> you refer to the left-hand side with $$. Provided it has a 'printable'
> type (int, char *, string), it should output.
>
> BR,
> Giacinto
>
> On Mon, May 6, 2019 at 11:28 AM r0ller wrote:
>>
>> Hi All,
>>
>> Is it possible in *any* way to get the left hand side symbol in an action of
>> a rule? Say, I have:
>>
>> A : B C
>> {
>>std:cout<<"left hand side symbol is:"<> };
>>
>> I tried to find it out myself and googled a lot but didn't find anything:(
>>
>> Best regards,
>> r0ller
>> ___
>> help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison
>
> ___
> help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison
___
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Re: how to get left hand side symbol in action
Yes, correct: I'd need the non terminal symbol itself.
Best regards,
r0ller
Eredeti levél
Feladó: Uxio Prego < uxio.pr...@gmail.com (Link -> mailto:uxio.pr...@gmail.com)
>
Dátum: 2019 május 6 14:30:10
Tárgy: Re: how to get left hand side symbol in action
Címzett: Giacinto Cifelli < gciof...@gmail.com (Link ->
mailto:gciof...@gmail.com) >
I thought they mean the [non terminal] **symbol**,
instead of the actual object?
Regards,
> On 6 May 2019, at 14:27, Giacinto Cifelli wrote:
>
> Hi,
>
> you refer to the left-hand side with $$. Provided it has a 'printable'
> type (int, char *, string), it should output.
>
> BR,
> Giacinto
>
> On Mon, May 6, 2019 at 11:28 AM r0ller wrote:
>>
>> Hi All,
>>
>> Is it possible in *any* way to get the left hand side symbol in an action of
>> a rule? Say, I have:
>>
>> A : B C
>> {
>> std:cout<<"left hand side symbol is:"<> };
>>
>> I tried to find it out myself and googled a lot but didn't find anything:(
>>
>> Best regards,
>> r0ller
>> ___
>> help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison
>
> ___
> help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison
___
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Re: how to get left hand side symbol in action
> On 6 May 2019, at 11:28, r0ller wrote:
>
> Hi All,
>
> Is it possible in *any* way to get the left hand side symbol in an action of
> a rule? Say, I have:
>
> A : B C
> {
> std:cout<<"left hand side symbol is:"< };
>
> I tried to find it out myself and googled a lot but didn't find anything:(
In the C++ parser, one can write:
std::cout << “LHS: " << yytname_[yylhs.type_get()] << std::endl;
Used for debugging, perhaps there is a more reliable macro.
___
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Re: how to get left hand side symbol in action
Sent from my iPhone
> On 6 May 2019, at 14:50, Hans Åberg wrote:
>
>
>> On 6 May 2019, at 11:28, r0ller wrote:
>>
>> Hi All,
>>
>> Is it possible in *any* way to get the left hand side symbol in an action of
>> a rule? Say, I have:
>>
>> A : B C
>> {
>>std:cout<<"left hand side symbol is:"<> };
>>
>> I tried to find it out myself and googled a lot but didn't find anything:(
>
> In the C++ parser, one can write:
> std::cout << “LHS: " << yytname_[yylhs.type_get()] << std::endl;
>
> Used for debugging, perhaps there is a more reliable macro.
>
>
Thanks for the hint.
Do you mean you know that it won’t work in a C parser or yacc compatibility?
>
> ___
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___
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Re: how to get left hand side symbol in action
> On 6 May 2019, at 15:21, uxio prego wrote:
>
>> On 6 May 2019, at 14:50, Hans Åberg wrote:
>>
>>> On 6 May 2019, at 11:28, r0ller wrote:
>>>
>>> Is it possible in *any* way to get the left hand side symbol in an action
>>> of a rule? Say, I have:
>>>
>>> A : B C
>>> {
>>> std:cout<<"left hand side symbol is:"<>> };
>>
>> In the C++ parser, one can write:
>> std::cout << “LHS: " << yytname_[yylhs.type_get()] << std::endl;
>>
>> Used for debugging, perhaps there is a more reliable macro.
>
> Thanks for the hint.
> Do you mean you know that it won’t work in a C parser or yacc compatibility?
It probably has a similar thing there. Check in the generated parser.
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Re: how to get left hand side symbol in action
Hi Hans,
Works like a charm! Thanks!
Best regards,
r0ller
Eredeti levél
Feladó: Hans Åberg < haber...@telia.com (Link -> mailto:haber...@telia.com) >
Dátum: 2019 május 6 14:50:48
Tárgy: Re: how to get left hand side symbol in action
Címzett: r0ller < r0l...@freemail.hu (Link -> mailto:r0l...@freemail.hu) >
> On 6 May 2019, at 11:28, r0ller wrote:
>
> Hi All,
>
> Is it possible in *any* way to get the left hand side symbol in an action of
> a rule? Say, I have:
>
> A : B C
> {
> std:cout<<"left hand side symbol is:"< };
>
> I tried to find it out myself and googled a lot but didn't find anything:(
In the C++ parser, one can write:
std::cout << “LHS: " << yytname_[yylhs.type_get()] << std::endl;
Used for debugging, perhaps there is a more reliable macro.
___
help-bison@gnu.org https://lists.gnu.org/mailman/listinfo/help-bison
Re: how to get left hand side symbol in action
> Le 6 mai 2019 à 14:50, Hans Åberg a écrit :
>
>
>> On 6 May 2019, at 11:28, r0ller wrote:
>>
>> Hi All,
>>
>> Is it possible in *any* way to get the left hand side symbol in an action of
>> a rule? Say, I have:
>>
>> A : B C
>> {
>>std:cout<<"left hand side symbol is:"<> };
>>
>> I tried to find it out myself and googled a lot but didn't find anything:(
>
> In the C++ parser, one can write:
> std::cout << “LHS: " << yytname_[yylhs.type_get()] << std::endl;
But it's an internal detail, there is no guarantee it won't change.
r0ller, what is your exact need?
___
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Re: how to get left hand side symbol in action
Hi Akim,
I bumped into this when writing the tech guide for my project last week. As you
know, in my project it's possible to generate the bison source if you've set up
your grammar rules in a db table (called grammar). However, in certain cases
one may want to have different action implementation than the default one and
actually in one case it's even a must: when you want to add a linguistic
feature at a syntactic level like marking a verb in a sentence as main verb. In
such a case an additional method must be called. Although, it's possible to
enter the action implementation code directly in the specific field (called
action) of the db record in question, it's more convenient to just put a file
name there and the source generator tool will do the job for you. The problem
emerges when you have more than one rule where you'd like to have the same
action implementation, for example:
A : B C
{
const node_info& main_node=sparser->get_node_info($1);
const node_info& dependent_node=sparser->get_node_info($2);
sparser->add_feature_to_leaf(main_node,"main_verb");
std::string parent_symbol="A";//<--Here the symbol is hardcoded
logger::singleton()==NULL?(void)0:logger::singleton()->log(0,parent_symbol+"->"+main_node.symbol+"
"+dependent_node.symbol);
$$=sparser->combine_nodes(parent_symbol,main_node,dependent_node);
}
D : E F
{
const node_info& main_node=sparser->get_node_info($1);
const node_info& dependent_node=sparser->get_node_info($2);
sparser->add_feature_to_leaf(main_node,"main_verb");
std::string parent_symbol="D";//<--Here the symbol is hardcoded
logger::singleton()==NULL?(void)0:logger::singleton()->log(0,parent_symbol+"->"+main_node.symbol+"
"+dependent_node.symbol);
$$=sparser->combine_nodes(parent_symbol,main_node,dependent_node);
}
This means, that one would need to save these two "snippets" in two different
files, say snippet1 and snippet2 and put the two file names in the action
fields of the corresponding db records.
While when being able to tell what the lhs symbol is, one implementation will
be enough for both "A:B C" and "D:E F" that can be saved in one file and the
same file name can be put in the action fields of the corresponding db records:
{
const node_info& main_node=sparser->get_node_info($1);
const node_info& dependent_node=sparser->get_node_info($2);
sparser->add_feature_to_leaf(main_node,"main_verb");
std::string parent_symbol=yytname_[yylhs.type_get()];//<--Here the symbol is
not hardcoded
logger::singleton()==NULL?(void)0:logger::singleton()->log(0,parent_symbol+"->"+main_node.symbol+"
"+dependent_node.symbol);
$$=sparser->combine_nodes(parent_symbol,main_node,dependent_node);
}
These examples you can find in the tech guide towards the end of section
'Generating syntactic rules and machine learning':
https://github.com/r0ller/alice/wiki/Technical-Guide-and-Documentation#Option-2-3
and the other one towards the end of section 'Tagging':
https://github.com/r0ller/alice/wiki/Technical-Guide-and-Documentation#Tagging
Though, as I changed it today after Hans's suggestion, you'll now find the same
implementation at those two places.
Thanks for any hints!:)
Best regards,
r0ller
Eredeti levél
Feladó: Akim Demaille < a...@lrde.epita.fr (Link -> mailto:a...@lrde.epita.fr) >
Dátum: 2019 május 6 18:09:56
Tárgy: Re: how to get left hand side symbol in action
Címzett: Hans Åberg < haber...@telia.com (Link -> mailto:haber...@telia.com) >
> Le 6 mai 2019 à 14:50, Hans Åberg a écrit :
>
>
>> On 6 May 2019, at 11:28, r0ller wrote:
>>
>> Hi All,
>>
>> Is it possible in *any* way to get the left hand side symbol in an action of
>> a rule? Say, I have:
>>
>> A : B C
>> {
>> std:cout<<"left hand side symbol is:"<> };
>>
>> I tried to find it out myself and googled a lot but didn't find anything:(
>
> In the C++ parser, one can write:
> std::cout << “LHS: " << yytname_[yylhs.type_get()] << std::endl;
But it's an internal detail, there is no guarantee it won't change.
r0ller, what is your exact need?
___
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Re: how to get left hand side symbol in action
> On 6 May 2019, at 18:09, Akim Demaille wrote:
>
>> Le 6 mai 2019 à 14:50, Hans Åberg a écrit :
>>
>>
>>> On 6 May 2019, at 11:28, r0ller wrote:
>>>
>>> Hi All,
>>>
>>> Is it possible in *any* way to get the left hand side symbol in an action
>>> of a rule? Say, I have:
>>>
>>> A : B C
>>> {
>>> std:cout<<"left hand side symbol is:"<>> };
>>>
>>> I tried to find it out myself and googled a lot but didn't find anything:(
>>
>> In the C++ parser, one can write:
>> std::cout << “LHS: " << yytname_[yylhs.type_get()] << std::endl;
>
> But it's an internal detail, there is no guarantee it won't change.
Right, so it might be a feature request for the longer term. Perhaps a
variation of $ and @ that gives access to the name, or the raw stack value in
case there are more stuff to access.
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