X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Floader.h;h=8d26a418a0f5d9cdec52a6ecc85160ff4ee1c4e4;hb=92644bf892df1220c8df67e1fc3da85dd02c53c5;hp=46c878b09ef6a65c63fad2a266d28befa358f2ef;hpb=98f563736e0837a429714b98656215503c607710;p=libs%2Fdatafile.git

diff --git a/source/loader.h b/source/loader.h
index 46c878b..8d26a41 100644
--- a/source/loader.h
+++ b/source/loader.h
@@ -1,240 +1,365 @@
-/*
-This file is part of libmspparser
+/* $Id$
+
+This file is part of libmspdatafile
 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 <fstream>
 #include <map>
-#include <msp/error.h>
+#include "except.h"
 #include "parser.h"
 #include "statement.h"
 #include "value.h"
 
 namespace Msp {
-namespace Parser {
+namespace DataFile {
 
+class Loader;
 class Statement;
 
-template<typename L>
+/**
+Base class for loader actions.
+*/
 class LoaderAction
 {
 public:
-	virtual void execute(L &, const Statement &) const=0;
+	/**
+	Called when a statement is to be loaded.
+	*/
+	virtual void execute(Loader &, const Statement &) const=0;
 	virtual ~LoaderAction() { }
 protected:
 	LoaderAction() { }
 };
 
+
+/**
+Loads a statement by calling a function that takes no arguments.
+*/
 template<typename L>
-class LoaderFunc0: public LoaderAction<L>
+class LoaderFunc0: public LoaderAction
 {
 public:
 	typedef void (L::*FuncType)();
-	
+
 	LoaderFunc0(FuncType f): func(f) { }
-	void execute(L &l, const Statement &st) const
+	void execute(Loader &l, const Statement &st) const
 	{
-		if(st.args.size()!=0) throw TypeError("Wrong number of arguments");
-		(l.*func)();
+		if(st.args.size()!=0) throw TypeError(st.get_location()+": Wrong number of arguments");
+		(dynamic_cast<L &>(l).*func)();
 	};
 private:
 	FuncType func;
 };
 
+
+/**
+Loads a statement by calling a function that takes one argument.
+*/
 template<typename L, typename A0>
-class LoaderFunc1: public LoaderAction<L>
+class LoaderFunc1: public LoaderAction
 {
 public:
 	typedef void (L::*FuncType)(A0);
-	
+
+	LoaderFunc1(FuncType f): func(f) { }
+	void execute(Loader &l, const Statement &st) const
+	{
+		if(st.args.size()!=1) throw TypeError(st.get_location()+": Wrong number of arguments");
+		(dynamic_cast<L &>(l).*func)(st.args[0].get<A0>());
+	}
+private:
+	FuncType func;
+};
+
+
+/**
+Loads a statement by calling a function that takes an array of values.
+*/
+template<typename L, typename A0>
+class LoaderFunc1<L, const std::vector<A0> &>: public LoaderAction
+{
+public:
+	typedef void (L::*FuncType)(const std::vector<A0> &);
+
 	LoaderFunc1(FuncType f): func(f) { }
-	void execute(L &l, const Statement &st) const
+	void execute(Loader &l, const Statement &st) const
 	{
-		if(st.args.size()!=1) throw TypeError("Wrong number of arguments");
-		(l.*func)(st.args[0].get<A0>());
+		std::vector<A0> values;
+		values.reserve(st.args.size());
+		for(ValueArray::const_iterator i=st.args.begin(); i!=st.args.end(); ++i)
+			values.push_back(i->get<A0>());
+		(dynamic_cast<L &>(l).*func)(values);
 	}
 private:
 	FuncType func;
 };
 
+
 template<typename L, typename A0, typename A1>
-class LoaderFunc2: public LoaderAction<L>
+class LoaderFunc2: public LoaderAction
 {
 public:
 	typedef void (L::*FuncType)(A0, A1);
-	
+
 	LoaderFunc2(FuncType f): func(f) { }
-	void execute(L &l, const Statement &st) const
+	void execute(Loader &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>());
+		if(st.args.size()!=2) throw TypeError(st.get_location()+": Wrong number of arguments");
+		(dynamic_cast<L &>(l).*func)(st.args[0].get<A0>(), st.args[1].get<A1>());
 	}
 private:
 	FuncType func;
 };
 
+
 template<typename L, typename A0, typename A1, typename A2>
-class LoaderFunc3: public LoaderAction<L>
+class LoaderFunc3: public LoaderAction
 {
 public:
 	typedef void (L::*FuncType)(A0, A1, A2);
-	
+
 	LoaderFunc3(FuncType f): func(f) { }
-	void execute(L &l, const Statement &st) const
+	void execute(Loader &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>());
+		if(st.args.size()!=3) throw TypeError(st.get_location()+": Wrong number of arguments");
+		(dynamic_cast<L &>(l).*func)(st.args[0].get<A0>(), st.args[1].get<A1>(), st.args[2].get<A2>());
 	}
 private:
 	FuncType func;
 };
 
+
 template<typename L, typename A0, typename A1, typename A2, typename A3>
-class LoaderFunc4: public LoaderAction<L>
+class LoaderFunc4: public LoaderAction
 {
 public:
 	typedef void (L::*FuncType)(A0, A1, A2, A3);
-	
+
 	LoaderFunc4(FuncType f): func(f) { }
-	void execute(L &l, const Statement &st) const
+	void execute(Loader &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>());
+		if(st.args.size()!=4) throw TypeError(st.get_location()+": Wrong number of arguments");
+		(dynamic_cast<L &>(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;
 };
 
-template<typename L, typename T>
-class LoadValue: public LoaderAction<L>
+
+template<typename L, typename T0>
+class LoadValue1: public LoaderAction
 {
 public:
-	typedef T L::ObjectType::*PointerType;
-	
-	LoadValue(PointerType p): ptr(p) { }
-	void execute(L &l, const Statement &st) const
+	typedef T0 L::*Pointer0Type;
+
+	LoadValue1(Pointer0Type p0): ptr0(p0) { }
+	void execute(Loader &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>();
+		if(st.args.size()!=1) throw TypeError(st.get_location()+": Wrong number of arguments");
+		dynamic_cast<typename L::Loader &>(l).get_object().*ptr0=st.args[0].get<T0>();
 	}
 private:
-	PointerType ptr;
+	Pointer0Type ptr0;
 };
 
-template<typename L, typename S>
-class SubLoader0: public LoaderAction<L>
+
+template<typename L, typename T0>
+class LoadValue1<L, T0 *>: public LoaderAction
 {
 public:
-	typedef typename S::ObjectType &(L::*FuncType)();
+	typedef T0 *L::*Pointer0Type;
 
-	SubLoader0(FuncType f): func(f) { }
-	void execute(L &l, const Statement &st) const
+	LoadValue1(Pointer0Type p0): ptr0(p0) { }
+	void execute(Loader &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);
+		if(st.args.size()!=1) throw TypeError(st.get_location()+": Wrong number of arguments");
+		typename L::Loader &ldr=dynamic_cast<typename L::Loader &>(l);
+		ldr.get_object().*ptr0=&ldr.get_collection().template get<T0>(st.args[0].get<std::string>());
 	}
 private:
-	FuncType func;
+	Pointer0Type ptr0;
 };
 
-template<typename L, typename S, typename A0>
-class SubLoader1: public LoaderAction<L>
+
+template<typename L, typename T0, typename T1>
+class LoadValue2: public LoaderAction
 {
 public:
-	typedef typename S::ObjectType &(L::*FuncType)(A0);
+	typedef T0 L::*Pointer0Type;
+	typedef T1 L::*Pointer1Type;
 
-	SubLoader1(FuncType f): func(f) { }
-	void execute(L &l, const Statement &st) const
+	LoadValue2(Pointer0Type p0, Pointer1Type p1): ptr0(p0), ptr1(p1) { }
+	void execute(Loader &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);
+		if(st.args.size()!=2) throw TypeError(st.get_location()+": Wrong number of arguments");
+		dynamic_cast<typename L::Loader &>(l).get_object().*ptr0=st.args[0].get<T0>();
+		dynamic_cast<typename L::Loader &>(l).get_object().*ptr1=st.args[1].get<T1>();
 	}
 private:
-	FuncType func;
+	Pointer0Type ptr0;
+	Pointer1Type ptr1;
 };
 
-template<typename C, typename L>
+
+/**
+Base class for data loaders.  To give loading capabilities to a class, create a
+public Loader class in it, derived from this class.  Typically a loader object
+contains a reference to the loaded object.  To make use of loading directly
+into data members, the Loader class must have a get_object() member function,
+returning that reference.  If direct loading of pointers is desired, the Loader
+class must also have a get_collection() member function, returning a collection
+to get pointers from.
+*/
 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)
-	{
-		while(p)
-		{
-			Statement st=p.parse();
-			if(st.valid)
-				load_statement(st);
-		}
-	}
-	virtual ~Loader()
-	{
-		for(typename ActionMap::iterator i=actions.begin(); i!=actions.end(); ++i)
-			delete i->second;
-	}
+	/**
+	Loads data from a statement.  This is normally only used by the Loader class
+	itself for loading sub-items, but needs to be public so it can be accessed
+	in derived objects.
+	*/
+	void load(const Statement &st);
+
+	/**
+	Loads statements from a parser.
+	*/
+	void load(Parser &p);
+
+	virtual ~Loader();
 protected:
-	typedef std::map<std::string, LoaderAction<L > *> ActionMap;
+	Loader(): cur_st(0) { }
 
-	C &obj;
-	
-	Loader(C &o): obj(o) { }
-	
+	/**
+	Adds a keyword that is loaded with a zero-argument 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)); }
+
+	/**
+	Adds a keyword that is loaded into a variable 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)); }
 
+	/**
+	Adds a keyword that is recognized but ignored.
+	*/
+	void add(const std::string &k)
+	{ add(k, 0); }
+
+	/**
+	Loads a sub-object from the statement being processed.  The Loader class of
+	the sub-object is automatically used.
+	*/
 	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))); }
+	void load_sub(S &s)
+	{ load_sub<typename S::Loader, S>(s); }
 
-	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))); }
+	/**
+	Loads a sub-object with a custom Loader class.
+	*/
+	template<typename L, typename S>
+	void load_sub(S &s)
+	{
+		if(!cur_st)
+			throw InvalidState("load_sub called without current statement");
+		L loader(s);
+		loader.load(*cur_st);
+	}
 
-	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;
+	template<typename S, typename T>
+	void load_sub(S &s, T &p)
+	{ load_sub<typename S::Loader, S, T>(s, p); }
 
-	void load_statement(const Statement &st)
+	/**
+	Loads a sub-object with a custom Loader class that takes one argument in
+	addition to to object to be loaded.
+	*/
+	template<typename L, typename S, typename T>
+	void load_sub(S &s, T &p)
 	{
-		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);
+		if(!cur_st)
+			throw InvalidState("load_sub called without current statement");
+		L loader(s, p);
+		loader.load(*cur_st);
 	}
+
+	/**
+	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
+	{
+		if(!cur_st)
+			throw InvalidState("get_source called without current statement");
+		return cur_st->source;
+	}
+private:
+	typedef std::map<std::string, LoaderAction *> ActionMap;
+
+	ActionMap       actions;
+	const Statement *cur_st;
+
+	void add(const std::string &, LoaderAction *);
+	void load_statement(const Statement &st);
 };
 
-} // 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)
+{
+	std::ifstream in(fn.c_str());
+	if(!in)
+		throw Exception("Couldn't open "+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)
+{
+	std::ifstream in(fn.c_str());
+	if(!in)
+		throw Exception("Couldn't open "+fn);
+
+	Parser parser(in, fn);
+	typename T::Loader loader(obj, arg);
+	loader.load(parser);
+}
+
+} // namespace DataFile
 } // namespace Msp
 
 #endif