Classes | |
struct | zypp::resfilter::ByKind |
Select ResObject by kind. More... | |
struct | zypp::resfilter::ByName |
Select ResObject by name. More... | |
struct | zypp::resfilter::BySource |
Select ResObject by source. More... | |
struct | zypp::resfilter::ByEdition< _Compare > |
Select ResObject by Edition using _Compare functor. More... | |
struct | zypp::resfilter::ByArch< _Compare > |
Select ResObject by Arch using _Compare functor. More... | |
struct | zypp::resfilter::ByInstalled |
Select PoolItem by installed. More... | |
struct | zypp::resfilter::ByUninstalled |
Select PoolItem by uninstalled. More... | |
struct | zypp::resfilter::ByTransact |
Select PoolItem by transact. More... | |
struct | zypp::resfilter::ByLock |
Select PoolItem by lock. More... | |
struct | zypp::resfilter::ByCapabilityIndex |
Select ResObject if at least one Capability with index index_r was found in dependency depType_r. More... | |
struct | zypp::resfilter::ByCapMatch |
Select ResObject if at least one Capability with index index_r was found in dependency depType_r. More... | |
struct | zypp::resfilter::ByCaIUninstalled |
Select PoolItem by uninstalled. More... | |
struct | zypp::resfilter::ByCaIInstalled |
Select PoolItem by installed. More... | |
struct | zypp::resfilter::ByCaITransact |
Select PoolItem by transact. More... | |
struct | zypp::resfilter::ByCaINotTransact |
Select PoolItem by not transact. More... | |
struct | zypp::resfilter::ByCaIKind |
Select CapAndItem by kind. More... | |
Typedefs | |
typedef std::unary_function< ResObject::constPtr, bool > | zypp::resfilter::ResObjectFilterFunctor |
typedef std::unary_function< PoolItem, bool > | zypp::resfilter::PoolItemFilterFunctor |
Functions | |
template<class _Res> | |
ByKind | zypp::resfilter::byKind () |
template<class _Compare> | |
ByEdition< _Compare > | zypp::resfilter::byEdition (const Edition &edition_r, _Compare cmp_r) |
template<class _Compare> | |
ByEdition< _Compare > | zypp::resfilter::byEdition (const Edition &edition_r) |
template<class _Compare> | |
ByArch< _Compare > | zypp::resfilter::byArch (const Arch &arch_r, _Compare cmp_r) |
template<class _Compare> | |
ByArch< _Compare > | zypp::resfilter::byArch (const Arch &arch_r) |
template<class _Res> | |
ByCaIKind | zypp::resfilter::byCaIKind () |
bool simplefilter( ResObject::Ptr );
bool
. Anything which is convertible into a bool
will do;ResObject
(e.g. ByKind, ByName) you may use Functors for building compex queries. to build more complex filters.
// some 'action' functor, printing and counting // ResObjects. struct PrintAndCount { PrintAndCount( unsigned & counter_r ) : _counter( counter_r ) {} bool operator()( ResObject::Ptr p ) const { DBG << *p << endl; ++_counter; return true; } unsigned & _counter; }; ResStore store; unsigned counter = 0; // print and count all resolvables store.forEach( PrintAndCount(counter) ); // print and count all resolvables named "kernel" counter = 0; store.forEach( ByName("kernel"), PrintAndCount(counter) ); // print and count all Packages named "kernel" counter = 0; store.forEach( chain( ByKind(ResTraits<Package>::kind), ByName("kernel") ), PrintAndCount(counter) ); // print and count all Packages not named "kernel" counter = 0; store.forEach( chain( ByKind(ResTraits<Package>::kind), not_c(ByName("kernel")) ), PrintAndCount(counter) ); // same as above ;) counter = 0; store.forEach( chain( ByKind(ResTraits<Package>::kind), chain( not_c(ByName("kernel")), PrintAndCount(counter) ) ), true_c() );
As you can see in the last example there is no difference in using a filter or an action functor, as both have the same signature. A difference of course is the way forEach interprets the returned value.
Consequently you can netgate and chain actions as well. Thus PrintAndCount(counter)
could be chain(Print(),Count(counter))
, if these functors are provided.
In case you already have functions or methods which do what you want, but thet don't perfectly match the required signature: Make yourself familiar with std::ptr_fun, mem_fun, bind1st, bind2nd and compose
. They are sometimes quite helpfull.
PrintAndCount
is an example how a functor can return data collected during the query. You ca easily write a collector, that takes a std:list<ResObject::Ptr>&
and fills it with the matches found.But as a rule of thumb, a functor should be lightweight. If you want to get data out, pass references to variables in (and assert these variables live as long as the query lasts). Or use FunctorRef.
Internally all functors are passed by value. Thus it would not help you to create an instance of some collecting functor, and pass it to the query. The query will then fill a copy of your functor, you won't get the data back. (Well, you probabely could, by using boosr::ref).
Why functors and not plain functions?
You can use plain functions if they don't have to deliver data back to the application. The C-style
approach is having functions that take a void * data
as last argument. This data
pointer is then passed arround and casted up and down.
If you look at a functor, you'll see that it contains both, the function to call (it's operator()
) and the data you'd otherwise pass as void * data
. That's nice and safe.
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Definition at line 150 of file ResFilters.h. |
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Definition at line 295 of file ResFilters.h. |
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Definition at line 169 of file ResFilters.h. |
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Definition at line 236 of file ResFilters.h. Referenced by zypp::resfilter::byEdition(). |
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Definition at line 241 of file ResFilters.h. References zypp::resfilter::byEdition(). |
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Definition at line 277 of file ResFilters.h. Referenced by zypp::resfilter::byArch(). |
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Definition at line 282 of file ResFilters.h. References zypp::resfilter::byArch(). |
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Definition at line 419 of file ResFilters.h. |