-/*
-This file is part of libmspparser
-Copyright © 2006 Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
-#ifndef MSP_PARSER_LOADER_H_
-#define MSP_PARSER_LOADER_H_
+#ifndef MSP_DATAFILE_LOADER_H_
+#define MSP_DATAFILE_LOADER_H_
#include <map>
-#include <msp/error.h>
+#include <msp/io/file.h>
+#include "loaderaction.h"
#include "parser.h"
#include "statement.h"
-#include "value.h"
namespace Msp {
-namespace Parser {
+namespace DataFile {
-class Statement;
+/**
+Base class for data loaders. This class only provides core functionality.
+You'll almost certainly want to use one of the BasicLoader classes instead.
-template<typename L>
-class LoaderAction
-{
-public:
- virtual void execute(L &, const Statement &) const=0;
- virtual ~LoaderAction() { }
-protected:
- LoaderAction() { }
-};
+Under normal circumstances, a class capable of being loaded should have a
+nested typed called Loader which resolves to a descendant of this class. If
+another structure is used, the loader object must be constructed manually.
-template<typename L>
-class LoaderFunc0: public LoaderAction<L>
-{
-public:
- typedef void (L::*FuncType)();
-
- LoaderFunc0(FuncType f): func(f) { }
- void execute(L &l, const Statement &st) const
- {
- if(st.args.size()!=0) throw TypeError("Wrong number of arguments");
- (l.*func)();
- };
-private:
- FuncType func;
-};
+A loader class should execute one or more calls to the various add() functions
+to register actions with expected keywords. Currently possible actions are
+calling a function of the loader, storing values in member variables of an
+object and ignoring the statement. If a unexpected keyword is encountered, an
+exception is thrown and the loading is aborted.
-template<typename L, typename A0>
-class LoaderFunc1: public LoaderAction<L>
-{
-public:
- typedef void (L::*FuncType)(A0);
-
- LoaderFunc1(FuncType f): func(f) { }
- void execute(L &l, const Statement &st) const
- {
- if(st.args.size()!=1) throw TypeError("Wrong number of arguments");
- (l.*func)(st.args[0].get<A0>());
- }
-private:
- FuncType func;
-};
+A sub-object can be loaded with one of the load_sub functions.
-template<typename L, typename A0, typename A1>
-class LoaderFunc2: public LoaderAction<L>
-{
-public:
- typedef void (L::*FuncType)(A0, A1);
-
- LoaderFunc2(FuncType f): func(f) { }
- void execute(L &l, const Statement &st) const
- {
- if(st.args.size()!=2) throw TypeError("Wrong number of arguments");
- (l.*func)(st.args[0].get<A0>(), st.args[1].get<A1>());
- }
-private:
- FuncType func;
-};
+When loading has finished successfully, the virtual function finish() is
+called. Any post-processing of the data should be placed here and not in the
+destructor.
-template<typename L, typename A0, typename A1, typename A2>
-class LoaderFunc3: public LoaderAction<L>
+See also classes ObjectLoader and CollectionObjectLoader in objectloader.h.
+*/
+class Loader
{
-public:
- typedef void (L::*FuncType)(A0, A1, A2);
-
- LoaderFunc3(FuncType f): func(f) { }
- void execute(L &l, const Statement &st) const
- {
- if(st.args.size()!=3) throw TypeError("Wrong number of arguments");
- (l.*func)(st.args[0].get<A0>(), st.args[1].get<A1>(), st.args[2].get<A2>());
- }
private:
- FuncType func;
-};
+ typedef std::map<StatementKey, LoaderAction *> ActionMap;
-template<typename L, typename A0, typename A1, typename A2, typename A3>
-class LoaderFunc4: public LoaderAction<L>
-{
-public:
- typedef void (L::*FuncType)(A0, A1, A2, A3);
-
- LoaderFunc4(FuncType f): func(f) { }
- void execute(L &l, const Statement &st) const
- {
- if(st.args.size()!=4) throw TypeError("Wrong number of arguments");
- (l.*func)(st.args[0].get<A0>(), st.args[1].get<A1>(), st.args[2].get<A2>(), st.args[3].get<A3>());
- }
-private:
- FuncType func;
-};
+ ActionMap actions;
+ Parser *cur_parser;
+ unsigned cur_level;
+ const Statement *cur_st;
+ bool sub_loaded;
+ bool direct;
+ std::list<Loader *> aux_loaders;
+protected:
+ bool check_sub_loads;
-template<typename L, typename T>
-class LoadValue: public LoaderAction<L>
-{
+ Loader();
public:
- typedef T L::ObjectType::*PointerType;
-
- LoadValue(PointerType p): ptr(p) { }
- void execute(L &l, const Statement &st) const
- {
- if(st.args.size()!=1) throw TypeError("Wrong number of arguments");
- l.get_object().*ptr=st.args[0].get<T>();
- }
-private:
- PointerType ptr;
-};
+ virtual ~Loader();
-template<typename L, typename S>
-class SubLoader0: public LoaderAction<L>
-{
-public:
- typedef typename S::ObjectType &(L::*FuncType)();
+ /** Loads statements from a parser. */
+ void load(Parser &p);
- SubLoader0(FuncType f): func(f) { }
- void execute(L &l, const Statement &st) const
- {
- if(st.args.size()!=0) throw TypeError("Wrong number of arguments");
- typename S::ObjectType &obj=(l.*func)();
- S sl(obj);
- sl.load(st);
- }
private:
- FuncType func;
-};
+ /** Loads data from a statement. */
+ void load(const Statement &st);
-template<typename L, typename S, typename A0>
-class SubLoader1: public LoaderAction<L>
-{
-public:
- typedef typename S::ObjectType &(L::*FuncType)(A0);
+ /** Loads statemsnts from a parser, feeding them directly to actions. */
+ void load_direct(Parser &, unsigned);
- SubLoader1(FuncType f): func(f) { }
- void execute(L &l, const Statement &st) const
- {
- if(st.args.size()!=1) throw TypeError("Wrong number of arguments");
- typename S::ObjectType &obj=(l.*func)(st.args[0].get<A0>());
- S sl(obj);
- sl.load(st);
- }
-private:
- FuncType func;
-};
+ /** Processes a single statement */
+ void load_statement(const Statement &st);
-template<typename C, typename L>
-class Loader
-{
-public:
- typedef C ObjectType;
-
- C &get_object() { return obj; }
- void load(const Statement &st)
- {
- for(std::list<Statement>::const_iterator i=st.sub.begin(); i!=st.sub.end(); ++i)
- load_statement(*i);
- }
- void load(Parser &p)
+protected:
+ /** Loads a sub-object from the statement being processed. The Loader class
+ of the sub-object is automatically used. */
+ template<typename S>
+ void load_sub(S &s)
{
- while(p)
- {
- Statement st=p.parse();
- if(st.valid)
- load_statement(st);
- }
+ typename S::Loader ldr(s);
+ load_sub_with(ldr);
}
- virtual ~Loader()
+
+ /** Loads a sub-object from the statement being processed with an extra
+ parameter for the Loader. The Loader class of the sub-object is
+ automatically used. */
+ template<typename S, typename T>
+ void load_sub(S &s, T &p)
{
- for(typename ActionMap::iterator i=actions.begin(); i!=actions.end(); ++i)
- delete i->second;
+ typename S::Loader ldr(s, p);
+ load_sub_with(ldr);
}
-protected:
- typedef std::map<std::string, LoaderAction<L > *> ActionMap;
- C &obj;
-
- Loader(C &o): obj(o) { }
-
+ /** Processes the current statement's substatements with another Loader. */
+ void load_sub_with(Loader &);
+
+ /** Adds a keyword that is loaded by calling a function. */
+ template<typename L>
void add(const std::string &k, void (L::*func)())
- { actions.insert(typename ActionMap::value_type(k, new LoaderFunc0<L>(func))); }
-
- template<typename A0>
+ { add(k, new LoaderFunc0<L>(func)); }
+
+ template<typename L, typename A0>
void add(const std::string &k, void (L::*func)(A0))
- { actions.insert(typename ActionMap::value_type(k, new LoaderFunc1<L, A0>(func))); }
-
- template<typename A0, typename A1>
+ { add(k, new LoaderFunc1<L, A0>(func)); }
+
+ template<typename L, typename A0, typename A1>
void add(const std::string &k, void (L::*func)(A0, A1))
- { actions.insert(typename ActionMap::value_type(k, new LoaderFunc2<L, A0, A1>(func))); }
-
- template<typename A0, typename A1, typename A2>
+ { add(k, new LoaderFunc2<L, A0, A1>(func)); }
+
+ template<typename L, typename A0, typename A1, typename A2>
void add(const std::string &k, void (L::*func)(A0, A1, A2))
- { actions.insert(typename ActionMap::value_type(k, new LoaderFunc3<L, A0, A1, A2>(func))); }
-
- template<typename A0, typename A1, typename A2, typename A3>
+ { add(k, new LoaderFunc3<L, A0, A1, A2>(func)); }
+
+ template<typename L, typename A0, typename A1, typename A2, typename A3>
void add(const std::string &k, void (L::*func)(A0, A1, A2, A3))
- { actions.insert(typename ActionMap::value_type(k, new LoaderFunc4<L, A0, A1, A2, A3>(func))); }
+ { add(k, new LoaderFunc4<L, A0, A1, A2, A3>(func)); }
- template<typename S>
- void add(const std::string &k, typename S::ObjectType &(L::*func)())
- { actions.insert(typename ActionMap::value_type(k, new SubLoader0<L, S>(func))); }
+ template<typename L, typename A0, typename A1, typename A2, typename A3, typename A4>
+ void add(const std::string &k, void (L::*func)(A0, A1, A2, A3, A4))
+ { add(k, new LoaderFunc5<L, A0, A1, A2, A3, A4>(func)); }
+
+ /** Adds a keyword that is loaded into a member of the loaded object. */
+ template<typename L, typename T0>
+ void add(const std::string &k, T0 L::*p0)
+ { add(k, new LoadValue1<L, T0>(p0)); }
+
+ template<typename L, typename T0, typename T1>
+ void add(const std::string &k, T0 L::*p0, T1 L::*p1)
+ { add(k, new LoadValue2<L, T0, T1>(p0, p1)); }
- template<typename S, typename A0>
- void add(const std::string &k, typename S::ObjectType &(L::*func)(A0))
- { actions.insert(typename ActionMap::value_type(k, new SubLoader1<L, S, A0>(func))); }
+ /** Adds a keyword that is recognized but ignored. */
+ void add(const std::string &k)
+ { add(k, 0); }
- template<typename T>
- void add(const std::string &k, T C::*p)
- { actions.insert(typename ActionMap::value_type(k, new LoadValue<L, T>(p))); }
private:
- ActionMap actions;
+ void add(const std::string &, LoaderAction *);
- void load_statement(const Statement &st)
- {
- typename ActionMap::iterator j=actions.find(st.keyword);
- if(j==actions.end())
- throw Exception(st.get_location()+": Unknown keyword '"+st.keyword+"'");
- j->second->execute(dynamic_cast<L &>(*this), st);
- }
+protected:
+ void add_auxiliary_loader(Loader &);
+
+private:
+ bool has_action(const StatementKey &) const;
+ LoaderAction *find_action(const StatementKey &) const;
+
+protected:
+ /** Returns the source of the statement being processed. This can be used
+ to implement relative paths in include-like statements. Note that the
+ source may not necessarily be a file. */
+ const std::string &get_source() const;
+
+ /** Returns the keyword of the statement being processed. Can be used to
+ implement dynamic keywords. */
+ const std::string &get_keyword() const;
+
+ virtual void finish() { }
};
-} // namespace Parser
+
+/**
+Loads an object from a file. The object must have a public Loader class.
+*/
+template<typename T>
+void load(T &obj, const std::string &fn)
+{
+ IO::BufferedFile in(fn);
+
+ Parser parser(in, fn);
+ typename T::Loader loader(obj);
+ loader.load(parser);
+}
+
+template<typename T, typename U>
+void load(T &obj, const std::string &fn, U &arg)
+{
+ IO::BufferedFile in(fn);
+
+ Parser parser(in, fn);
+ typename T::Loader loader(obj, arg);
+ loader.load(parser);
+}
+
+} // namespace DataFile
} // namespace Msp
#endif
projects / libs / datafile.git / blobdiff