ezc/src/generator.h

/*
 * This file is a part of EZC -- Easy templating in C++
 * and is distributed under the (new) BSD licence.
 * Author: Tomasz Sowa <t.sowa@ttmath.org>
 */

/* 
 * Copyright (c) 2007-2011, Tomasz Sowa
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *    
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *    
 *  * Neither the name Tomasz Sowa nor the names of contributors to this
 *    project may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */


#ifndef headerfile_ezc_generator
#define headerfile_ezc_generator

#include "pattern.h"
#include "functions.h"
#include <sstream>
#include <fstream>

namespace Ezc
{
/*
StreamType
 we use only method write(const wchar_t * str, size_t len) from the stream
*/
template<class StreamType>
class Generator
{
public:

	Generator();

	void SetMax(int max_items_, int max_for_items_);

	// recognizing some special characters in text patterns (item_text in Patterns)
	// \r will be a carriage return (13)
	// \n will be a new line (10)
	// \t will be a tabulator (9)
	// \s will be a space
	// \\ will be one '\'
	// if the second character is different from those shown above the first slash will be printed
	// so "\x" gives "\x"
	// default: false
	void RecognizeSpecialChars(bool spec);

	// trimming white characters (at the beginning and at the end of an item_text)
	// (special char \s if enabled is not treated as a white character here)
	// default: false 
	void TrimWhite(bool trim);

	// skipping new line characters (from the whole string in an item_text)
	// but you can use a new line character written as "\n" (if special chars are turn on)
	// default: false
	void SkipNewLine(bool skip);

	// the main methods for generating
	void Generate(StreamType & o, Pattern & p, Functions<StreamType> & f);

	// this method is used only if the pattern has cached functions
	void Generate(StreamType & o, Pattern & p);


private:
	
	StreamType * output_stream;
	Pattern    * pattern;
	Functions<StreamType> * functions;
	
	// temporary error messages
	std::wstring temp_msg;

	bool break_generating;
	int current_item;
	int max_items;
	int max_for_items;
	bool special_chars;
	bool trim_white;
	bool skip_new_line;

	// an empty string for info objects
	// when there is no any parameters
	const std::wstring empty;


	// a stack item for 'for' statements
	// currently only one item (iteration)
	struct StackItem
	{
		int iter;
	};

	// a stack for 'for' statements
	std::vector<StackItem> stack_tab;

	bool Find(const Item::Function & item_fun, typename Functions<StreamType>::Function ** function);
	
	void Call(typename Functions<StreamType>::Function * function, FunInfo<StreamType> & info);
	bool Call(Item::Function & function, bool * info_res = 0, typename Functions<StreamType>::Function ** pfun = 0);
	void Call(typename Functions<StreamType>::Function * function, std::vector<std::wstring> & params, bool * info_res = 0);
	
	void CallUserFunction(typename Functions<StreamType>::Function * function, FunInfo<StreamType> & info);
	void CallVariable(typename Functions<StreamType>::Function * function, FunInfo<StreamType> & info);
	
	wchar_t CreateSpecialChar(wchar_t c);
	const wchar_t * PrintSpecialChar(const wchar_t * start, const wchar_t * end);
	void PrintSpecialText(const wchar_t * start, const wchar_t * end);
	void PrintNormalText(const wchar_t * start, const wchar_t * end);
	void TrimWhite(const wchar_t *& start, const wchar_t *& end);
	void SkipWhite(const wchar_t *& str);
	int  StrToInt(const wchar_t * str, const wchar_t ** str_end);

	void CreateMsg(const wchar_t * type, const wchar_t * arg = 0);
	void CreateMsg(const std::wstring & type, const std::wstring & arg);
	void CreateMsg(const std::wstring & type);
	void CreateUnknownMsg(const std::wstring & fun);

	void MakeTextIf_go(Item & item, bool result);
	bool MakeTextIfindexnumber(Item & item, bool & result);
	void MakeTextIf(Item & item);
	void MakeTextIfno(Item & item);
	void MakeTextIfany(Item & item);
	void MakeTextIfone(Item & item);
	void MakeTextIfanyno(Item & item);
	void MakeTextIfoneno(Item & item);
	void MakeTextIfindex(Item & item);
	void MakeTextForLoop(Item & item, typename Functions<StreamType>::Function * function);
	void MakeTextFor(Item & item);
	void MakeItemText(Item & item);
	void MakeTextContainer(Item & item);
	void MakeTextNormal(Item & item);
	void MakeTextIs(Item & item);
	void MakeTextIsno(Item & item);
	void MakeTextDefine(Item & item);
	void MakeText(Item & item);

}; // class Generator






template<class StreamType>
Generator<StreamType>::Generator()
{
	output_stream = 0;
	pattern       = 0;
	functions     = 0;

	max_items     = 50000;
	max_for_items = 5000;
	special_chars = false;
	trim_white    = false;
	skip_new_line = false;
}




template<class StreamType>
void Generator<StreamType>::SetMax(int max_items_, int max_for_items_)
{
	max_items     = max_items_;
	max_for_items = max_for_items_;
}


template<class StreamType>
void Generator<StreamType>::RecognizeSpecialChars(bool spec)
{
	special_chars = spec;
}


template<class StreamType>
void Generator<StreamType>::TrimWhite(bool trim)
{
	trim_white = trim;
}


template<class StreamType>
void Generator<StreamType>::SkipNewLine(bool skip)
{
	skip_new_line = skip;
}


template<class StreamType>
void Generator<StreamType>::Generate(StreamType & o, Pattern & p, Functions<StreamType> & f)
{
	output_stream = &o;
	pattern       = &p;
	functions     = &f;

	break_generating = false;
	current_item     = 0;

	MakeText( pattern->item_root );
}


template<class StreamType>
void Generator<StreamType>::Generate(StreamType & o, Pattern & p)
{
	output_stream = &o;
	pattern       = &p;
	functions     = 0;

	break_generating = false;
	current_item     = 0;

	MakeText( pattern->item_root );
}






template<class StreamType>
bool Generator<StreamType>::Find(const Item::Function & item_fun, typename Functions<StreamType>::Function ** function)
{
	if( !functions )
	{
		if( item_fun.fun_cache )
		{
			*function = reinterpret_cast<typename Functions<StreamType>::Function*>(item_fun.fun_cache);
			return true;
		}
		else
		{
			CreateUnknownMsg(item_fun.name);
			return false;
		}
	}

	if( !functions->Find(item_fun.name, function) )
	{
		CreateUnknownMsg(item_fun.name);
		return false;
	}
	
return true;	
}


template<class StreamType>
void Generator<StreamType>::CallUserFunction(typename Functions<StreamType>::Function * function, FunInfo<StreamType> & info)
{
	if( function->is_running )
	{
		// recurrences are not allowed
		CreateMsg(L"the function is being executed");
		return;
	}

	function->is_running = true;
	(function->user_function)(info);
	function->is_running = false;
}



template<class StreamType>
void Generator<StreamType>::CallVariable(typename Functions<StreamType>::Function * function, FunInfo<StreamType> & info)
{
	info.res = !function->variable.empty();
}



template<class StreamType>
void Generator<StreamType>::Call(typename Functions<StreamType>::Function * function, FunInfo<StreamType> & info)
{
	info.Clear();

	if( stack_tab.empty() )
		info.iter = 0;
	else
		info.iter = stack_tab.back().iter;

	if( function->type == Functions<StreamType>::function )
		CallUserFunction(function, info);
	else
		CallVariable(function, info);
}




// return: true if a function or variable was found and called
template<class StreamType>
bool Generator<StreamType>::Call(Item::Function & item_fun, bool * info_res, typename Functions<StreamType>::Function ** pfun)
{
typename Functions<StreamType>::Function * fun;
bool called = false;

	if( item_fun.params.empty() )
	{
		FunInfo<StreamType> info(*output_stream, item_fun.params, empty);

		if( Find(item_fun, &fun) )
		{
			Call(fun, info);
			called = true;
		}

		if( info_res )
			*info_res = info.res;
	}
	else
	{
		FunInfo<StreamType> info(*output_stream, item_fun.params, item_fun.params[0]);

		if( Find(item_fun, &fun) )
		{
			Call(fun, info);
			called = true;
		}

		if( info_res )
			*info_res = info.res;
	}

	if( called && pfun )
		*pfun = fun;

return called;
}




// it calls the function pointed by pfun
template<class StreamType>
void Generator<StreamType>::Call(typename Functions<StreamType>::Function * function, std::vector<std::wstring> & params, bool * info_res)
{
	if( params.empty() )
	{
		FunInfo<StreamType> info(*output_stream, params, empty);
		Call(function, info);

		if( info_res )
			*info_res = info.res;
	}
	else
	{
		FunInfo<StreamType> info(*output_stream, params, params[0]);
		Call(function, info);

		if( info_res )
			*info_res = info.res;
	}
}




template<class StreamType>
wchar_t Generator<StreamType>::CreateSpecialChar(wchar_t c)
{
wchar_t res = 0;

	if( c == 'r' )
		res = '\r';
	else
	if( c == 'n' )
		res = '\n';
	else
	if( c == 't' )
		res = '\t';
	else
	if( c == 's' )
		res = ' ';
	else
	if( c == '\\' )
		res = '\\';

return res;
}



// a special character is precedeed by a slash '\'
// if the special character is unknown the first slash is printing
// so "\t" gives one character of code 9
// and "\x" gives "\x" 
template<class StreamType>
const wchar_t * Generator<StreamType>::PrintSpecialChar(const wchar_t * start, const wchar_t * end)
{
wchar_t special = 0;

	if( *start == '\\' && (start+1) != end )
		special = CreateSpecialChar(*(start+1));

	if( special )
	{
		output_stream->write(&special, 1);
		start += 2;
	}
	else
	{
		if( !skip_new_line || *start != 10 )
			output_stream->write(start, 1);

		start += 1;
	}

return start;
}


template<class StreamType>
void Generator<StreamType>::PrintSpecialText(const wchar_t * start, const wchar_t * end)
{
	while( start != end )
	{
		const wchar_t * end2 = start;

		// looking for a first new line character or a special char
		// (for new line only if skip_new_line is true)
		while( end2 != end && *end2 != '\\' && (!skip_new_line || *end2 != 10) )
			end2 += 1;

		// printing the first part of the text
		if( start != end2 )
			output_stream->write(start, end2 - start);

		start = end2;
		
		// skipping one or more new line characters or special chars
		// (new lines only if skip_new_line is true)
		while( start != end && (*start == '\\' || (skip_new_line && *start == 10)) )
			start = PrintSpecialChar(start, end);
	}
}


template<class StreamType>
void Generator<StreamType>::PrintNormalText(const wchar_t * start, const wchar_t * end)
{
	if( skip_new_line )
	{
		while( start != end )
		{
			const wchar_t * end2 = start;

			// looking for a first new line character
			while( end2 != end && *end2 != 10 )
				end2 += 1;

			// printing the first part of the text (until the new line)
			if( start != end2 )
				output_stream->write(start, end2 - start);

			start = end2;
			
			// skipping one or more new line characters
			while( start != end && *start == 10 )
				start += 1;
		}
	}
	else
	{
		if( start != end )
			output_stream->write(start, end-start);
	}
}


template<class StreamType>
void Generator<StreamType>::TrimWhite(const wchar_t *& start, const wchar_t *& end)
{
	while( start != end && pattern->IsWhite(*start) )
		++start;

	while( start != end && pattern->IsWhite(*(end-1)) )
		--end;
}


template<class StreamType>
void Generator<StreamType>::SkipWhite(const wchar_t *& str)
{
	while( pattern->IsWhite(*str) )
		str += 1;
}



template<class StreamType>
int Generator<StreamType>::StrToInt(const wchar_t * str, const wchar_t ** str_end)
{
int res = 0;

	SkipWhite(str);

	// overflow is not checked

	while( *str>='0' && *str<='9' )
	{
		res *= 10;
		res += *str - '0';
		str += 1;
	}

	SkipWhite(str);
	*str_end = str;

return res;
}




template<class StreamType>
void Generator<StreamType>::CreateMsg(const wchar_t * type, const wchar_t * arg)
{
	pattern->CreateMsg(temp_msg, type, arg);
	output_stream->write(temp_msg.c_str(), temp_msg.size());
}



template<class StreamType>
void Generator<StreamType>::CreateMsg(const std::wstring & type, const std::wstring & arg)
{
	CreateMsg(type.c_str(), arg.c_str());
}



template<class StreamType>
void Generator<StreamType>::CreateMsg(const std::wstring & type)
{
	CreateMsg(type.c_str());
}


template<class StreamType>
void Generator<StreamType>::CreateUnknownMsg(const std::wstring & fun)
{
	CreateMsg(L"unknown function", fun.c_str());
}




template<class StreamType>
void Generator<StreamType>::MakeItemText(Item & item)
{
const wchar_t * start = item.text.c_str();
const wchar_t * end   = item.text.c_str() + item.text.size();

	if( trim_white )
		TrimWhite(start, end);

	if( special_chars )
		PrintSpecialText(start, end);
	else
		PrintNormalText(start, end);
}


template<class StreamType>
void Generator<StreamType>::MakeTextContainer(Item & item)
{
	std::vector<Item*>::iterator i = item.item_tab.begin();

	for( ; i != item.item_tab.end() && !break_generating ; ++i )
		MakeText(**i);
}



template<class StreamType>
void Generator<StreamType>::MakeTextNormal(Item & item)
{
	if( item.functions.size() != 1 )
		return;

	typename Functions<StreamType>::Function * pfun;
	bool called = Call(item.functions[0], 0, &pfun);

	if( called && pfun->type == Functions<StreamType>::variable )
		(*output_stream) << pfun->variable;
}



template<class StreamType>
void Generator<StreamType>::MakeTextIf_go(Item & item, bool result)
{
	if( result )
	{
		if( item.item_tab.size() > 0 )
			MakeText( *item.item_tab[0] );
	}
	else
	{
		// second element can be (or not -- it's from [else])
		if( item.item_tab.size() > 1 )
			MakeText( *item.item_tab[1] );
	}
}



template<class StreamType>
void Generator<StreamType>::MakeTextIf(Item & item)
{
bool info_res;

	if( item.functions.size() != 1 )
		return;

	if( !Call(item.functions[0], &info_res) )
		return;

	MakeTextIf_go(item, info_res);
}


template<class StreamType>
void Generator<StreamType>::MakeTextIfno(Item & item)
{
bool info_res;

	if( item.functions.size() != 1 )
		return;

	if( !Call(item.functions[0], &info_res) )
		return;

	MakeTextIf_go(item, !info_res);
}


template<class StreamType>
void Generator<StreamType>::MakeTextIfany(Item & item)
{
	std::vector<typename Item::Function>::iterator d = item.functions.begin();
	unsigned how_many_true = 0;
	bool info_res;

	for( ; d != item.functions.end() ; ++d )
	{
		if( !Call(*d, &info_res) )
			return;

		if( info_res )
			++how_many_true;
	}

	MakeTextIf_go(item, how_many_true == item.functions.size());
}


template<class StreamType>
void Generator<StreamType>::MakeTextIfone(Item & item)
{
	std::vector<typename Item::Function>::iterator d = item.functions.begin();
	unsigned how_many_true = 0;
	bool info_res;

	for( ; d != item.functions.end() ; ++d )
	{
		if( Call(*d, &info_res) && info_res )
		{
			// there is no sense to go through all functions
			++how_many_true;
			break;
		}
	}

	MakeTextIf_go(item, how_many_true > 0);
}


template<class StreamType>
void Generator<StreamType>::MakeTextIfanyno(Item & item)
{
	std::vector<typename Item::Function>::iterator d = item.functions.begin();
	unsigned how_many_true = 0;
	bool info_res;

	for( ; d != item.functions.end() ; ++d )
	{
		if( !Call(*d, &info_res) )
			return;

		if( info_res )
			++how_many_true;
	}

	MakeTextIf_go(item, how_many_true == 0);
}


template<class StreamType>
void Generator<StreamType>::MakeTextIfoneno(Item & item)
{
	std::vector<typename Item::Function>::iterator d = item.functions.begin();
	unsigned how_many_false = 0;
	bool info_res;

	for( ; d != item.functions.end() ; ++d )
	{
		if( Call(*d, &info_res) && !info_res )
			++how_many_false;
	}

	MakeTextIf_go(item, how_many_false > 0);
}



template<class StreamType>
void Generator<StreamType>::MakeTextIs(Item & item)
{
bool info_res1, info_res2;

	if( item.functions.size() != 2 )
		return;

	if( !Call(item.functions[0], &info_res1) )
		return;

	if( !Call(item.functions[1], &info_res2) )
		return;
	
	MakeTextIf_go(item, info_res1 == info_res2);
}


template<class StreamType>
void Generator<StreamType>::MakeTextIsno(Item & item)
{
bool info_res1, info_res2;

	if( item.functions.size() != 2 )
		return;

	if( !Call(item.functions[0], &info_res1) )
		return;

	if( !Call(item.functions[1], &info_res2) )
		return;
	
	MakeTextIf_go(item, info_res1 != info_res2);
}







template<class StreamType>
bool Generator<StreamType>::MakeTextIfindexnumber(Item & item, bool & result)
{
	if( item.functions.size() != 1 || stack_tab.empty() )
		return false;

	const wchar_t * number_text = item.functions[0].name.c_str();
	const wchar_t * last_char;

	int number = StrToInt(number_text, &last_char);

	if( *last_char != '\0' )
	{
		CreateMsg(L"if-index: syntax error");
		return false;
	}

	result = (stack_tab.back().iter == number);

return true;
}



template<class StreamType>
void Generator<StreamType>::MakeTextIfindex(Item & item)
{
	if( item.functions.size() != 1 )
		return;

	bool result = false;

	if( !stack_tab.empty() )
	{
		if( item.functions[0].name == L"odd" )
		{
			result = (stack_tab.back().iter & 1) == 1;
		}
		else
		if( item.functions[0].name == L"even" )
		{
			result = (stack_tab.back().iter & 1) == 0;
		}
		else
		if( item.functions[0].name == L"first" )
		{
			result = stack_tab.back().iter == 0;
		}
		else
		{
			if( !MakeTextIfindexnumber(item, result) )
				return;
		}
	}

	MakeTextIf_go(item, result);
}



template<class StreamType>
void Generator<StreamType>::MakeTextForLoop(Item & item, typename Functions<StreamType>::Function * function)
{
bool info_res;

	for( ; !break_generating ; stack_tab.back().iter += 1 )
	{
		if( stack_tab.back().iter >= max_for_items )
		{
			CreateMsg(item.functions[0].name.c_str(),
					  L"function exceeded a limit for a [for] statement");	
			break;
		}

		Call(function, item.functions[0].params, &info_res);

		if( !info_res )
			break;

		if( !item.item_tab.empty() )
			MakeText( *item.item_tab[0] ); // should be only one item - item_container
	}
}


template<class StreamType>
void Generator<StreamType>::MakeTextFor(Item & item)
{
	if( item.functions.size() != 1 )
		return;

	typename Functions<StreamType>::Function * function;

	if( !Find(item.functions[0], &function) )
		return;

	StackItem s;
	s.iter = 0;
	stack_tab.push_back(s);

	MakeTextForLoop(item, function);

	stack_tab.erase(--stack_tab.end());
}



template<class StreamType>
void Generator<StreamType>::MakeTextDefine(Item & item)
{
	if( !functions )
	{
		CreateMsg(L"def statement is not available when used without functions set");
		return;
	}

	if( item.functions.size() == 1 )
	{
		// inserting a new variable
		if( item.functions[0].params.size() == 1 )
			functions->Insert(item.functions[0].name, item.functions[0].params[0]);
	}
	else
	if( item.functions.size() == 2 )
	{
		typename Functions<StreamType>::Function * function;
		
		if( Find(item.functions[1], &function) )
		{
			if( function->type == Functions<StreamType>::function )
			{
				// inserting a new function
				functions->Insert(item.functions[0].name, function->user_function);
			}
			else
			{
				// inserting a new variable (the value is copied)
				functions->Insert(item.functions[0].name, function->variable);
			}
		}
	}
}




template<class StreamType>
void Generator<StreamType>::MakeText(Item & item)
{
	if( break_generating )
		return;
		
	if( ++current_item > max_items )
	{
		break_generating = true;
		CreateMsg(L"Generator exceeded allowed number of elements");	
		return;
	}
	
	if     ( item.type == Item::item_text )		MakeItemText(item);
	else if( item.type == Item::item_container )MakeTextContainer(item);
	else if( item.type == Item::item_normal )	MakeTextNormal(item);
	else if( item.type == Item::item_if )		MakeTextIf(item);
	else if( item.type == Item::item_ifno )		MakeTextIfno(item);
	else if( item.type == Item::item_ifany )	MakeTextIfany(item);
	else if( item.type == Item::item_ifone )	MakeTextIfone(item);
	else if( item.type == Item::item_ifanyno )	MakeTextIfanyno(item);
	else if( item.type == Item::item_ifoneno )	MakeTextIfoneno(item);
	else if( item.type == Item::item_ifindex )	MakeTextIfindex(item);
	else if( item.type == Item::item_is )		MakeTextIs(item);
	else if( item.type == Item::item_isno )		MakeTextIsno(item);
	else if( item.type == Item::item_for )		MakeTextFor(item);
	else if( item.type == Item::item_def )		MakeTextDefine(item);
	else if( item.type == Item::item_err )
		CreateMsg(L"a wrong directive");
}




} // namespace Ezc


#endif