bring the plain query utilities back into lib

This commit is contained in:
Fischlurch 2012-12-02 23:32:30 +01:00
parent a79ba2c507
commit 6c8bf1f9e4
2 changed files with 328 additions and 4 deletions

View file

@ -1,8 +1,8 @@
/*
Query - interface for generic queries
QueryUtil - support for working with terms and queries
Copyright (C) Lumiera.org
2008, Hermann Vosseler <Ichthyostega@web.de>
2008, 2012 Hermann Vosseler <Ichthyostega@web.de>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
@ -23,8 +23,7 @@
#include "lib/util.hpp"
#include "lib/symbol.hpp"
#include "include/logging.h"
#include "common/query.hpp"
#include "lib/query-util.hpp"
#include <boost/algorithm/string.hpp>
#include <boost/regex.hpp>

325
src/lib/query-util.hpp Normal file
View file

@ -0,0 +1,325 @@
/*
QUERY-UTIL.hpp - support for working with terms and queries
Copyright (C) Lumiera.org
2008, 2012 Hermann Vosseler <Ichthyostega@web.de>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef LIB_QUERY_UTIL_H
#define LIB_QUERY_UTIL_H
#include "lib/bool-checkable.hpp"
#include "lib/typed-counter.hpp"
#include "lib/iter-adapter.hpp"
#include "lib/nocopy.hpp"
#include "lib/symbol.hpp"
#include "lib/util.hpp"
#include <boost/lexical_cast.hpp>
#include <tr1/memory>
#include <typeinfo>
#include <cctype>
#include <string>
namespace lib {
using lib::IxID;
using lib::Symbol;
using lib::Literal;
using util::unConst;
using boost::lexical_cast;
using std::string;
#ifdef false /////////////////////////////////////////////////////////////////////WIP
/* ==== common definitions for rule based queries ==== */
class Goal;
class Resolution;
class QueryResolver;
/** Allow for taking ownership of a result set */
typedef std::tr1::shared_ptr<Resolution> PReso;
/**
* Query ABC: unspecific goal for resolution or retrieval.
* Goal elements are used within the backbone of a generic query system
* to access individual resolution mechanisms based on an internal classification
* of the type of query.
*/
class Goal
: util::no_copy_by_client
{
public:
virtual ~Goal() ;
enum Kind
{ GENERIC = 0
, DISCOVERY
};
struct QueryID
{
Kind kind;
IxID type;
};
QueryID const&
getQID() const
{
return id_;
}
/**
* Single Solution, possibly part of a result set.
* A pointer-like object, usually to be down-casted
* to a specifically typed Query::Cursor
* @see Resolution
*/
class Result
: public lib::BoolCheckable<Result>
{
void* cur_;
protected:
void point_at(void* p) { cur_ = p; }
template<typename RES>
RES&
access()
{
REQUIRE (cur_);
return *reinterpret_cast<RES*> (cur_);
}
public:
bool isValid() const { return bool(cur_); }
Result() : cur_(0) { } ///< create an NIL result
};
protected:
QueryID id_;
Goal (QueryID qid)
: id_(qid)
{ }
};
inline bool
operator== (Goal::QueryID const& id1, Goal::QueryID const& id2)
{
return id1.kind == id2.kind
&& id1.type == id2.type;
}
inline bool
operator!= (Goal::QueryID const& id1, Goal::QueryID const& id2)
{
return ! (id1 == id2);
}
/** Context used for generating type-IDs to denote
* the specific result types of issued queries */
typedef lib::TypedContext<Goal::Result> ResultType;
template<typename RES>
inline IxID
getResultTypeID() ///< @return unique ID denoting result type RES
{
return ResultType::ID<RES>::get();
}
/**
* Generic interface to express a query
* for specifically typed result elements
* providing some capabilities or fulfilling
* some properties. This is a generic umbrella
* for several kinds of queries and provides a
* mechanism for uniform usage of various
* resolution mechanisms.
*
* Any query bears an internal type classification and can be
* represented in a common syntactical form based on predicate logic.
* Query instances are created by some facilities allowing to query for objects.
* These query providers \em do know the specific kind (type) of query to expose.
* While client code uses these queries only by reference, there is the possibility
* to involve a generic QueryResolver, which -- behind the scenes -- manages a registry
* of specific resolution mechanisms. This way, clients may retrieve a set of results,
* each representing a possible solution to the posed query.
*
* @note until really integrating a rules based system
* this is largely dummy placeholder implementation.
* Some more specific query resolvers are available already,
* so, depending on the circumstances the actual resolution might be
* substantial or just a fake.
* @warning especially the classical resolution-type queries are just
* faked and use the given query-string as-is, without any normalisation.
* Moreover, as especially the fake-configrules match by string comparison,
* this may led to unexpected mis-matches.
*/
template<class RES>
class Query
: public Goal
{
protected:
static QueryID
defineQueryTypeID (Kind queryType = Goal::GENERIC)
{
QueryID id = {queryType, getResultTypeID<RES>() };
return id;
}
class Builder;
public:
Query()
: Goal (defineQueryTypeID())
{ }
explicit
Query (string querySpec)
: Goal (defineQueryTypeID(Goal::GENERIC))
{
UNIMPLEMENTED("how to issue generic queries");////////////////////////////////////////////////////////////////////////////////////////////TODO
}
static Builder
build (Kind queryType = Goal::GENERIC);
/* results retrieval */
class Cursor
: public Goal::Result
{
public:
typedef RES value_type;
typedef RES& reference;
typedef RES* pointer;
RES& operator* () { return access<RES>(); }
RES* operator->() { return & access<RES>(); }
void point_at(RES* r){ Goal::Result::point_at(r);}
void point_at(RES& r){ Goal::Result::point_at(&r);}
};
typedef lib::IterAdapter<Cursor,PReso> iterator;
iterator operator() (QueryResolver const& resolver) const;
iterator resolveBy (QueryResolver const& resolver) const;
friend size_t
hash_value (Query const& q)
{
UNIMPLEMENTED("generic standard representation");////////////////////////////////////////////////////////////////////////////////////////////TODO
}
friend bool
operator== (Query const& q1, Query const& q2)
{
UNIMPLEMENTED("how to define equality on queries");////////////////////////////////////////////////////////////////////////////////////////////TODO
}
protected:
Query (QueryID qID)
: Goal (qID)
{ }
friend class Builder;
};
/**
* Helper for establishing,
* reworking and remolding queries.
*/
template<class RES>
class Query<RES>::Builder
{
string predicateForm_;
public:
const string
asKey() const
{
return "type("
+ lexical_cast<string> (getResultTypeID<RES>())
+ "), "+predicateForm_;
}
};
#endif /////////////////////////////////////////TODO
namespace query {
/** ensure standard format for a given id string.
* Trim, sanitise and ensure the first letter is lower case.
* @note modifies the given string ref in place
*/
void normaliseID (string& id);
/** count the top-level predicates in the query string.
* usable for ordering queries, as more predicates usually
* mean more conditions, i.e. more constriction
*/
uint countPred (const string&);
const string extractID (Symbol, const string& termString);
const string removeTerm (Symbol, string& termString);
template<typename TY>
const string
buildTypeID()
{
string typeID (typeid(TY).name());
normaliseID (typeID);
return typeID;
}
}} // namespace lib::query
#endif