added: Big::FromBig() and an operator= and a contructor

for converting from another kind of a Big class
added:  to the parser: avg(), sum()


git-svn-id: svn://ttmath.org/publicrep/ttmath/trunk@56 e52654a7-88a9-db11-a3e9-0013d4bc506e

ttmath/ttmathbig.h

@@ -1501,10 +1501,38 @@ public:
 
 	/*!
 	*
-	*	convertion method
+	*	convertion methods
 	*
 	*/
 
+
+	/*!
+		converting from another type of a Big object
+	*/
+	template<uint another_exp, uint another_man>
+	uint FromBig(const Big<another_exp, another_man> & another)
+	{
+		info = another.info;
+
+		if( exponent.FromInt(another.exponent) )
+			return 1;
+
+		uint man_len_min = (man < another_man)? man : another_man;
+		uint i;
+
+		for( i = 0 ; i<man_len_min ; ++i )
+			mantissa.table[man-1-i] = another.mantissa.table[another_man-1-i];
+	
+		for( ; i<man ; ++i )
+			mantissa.table[man-1-i] = 0;
+		
+		// mantissa is standardized
+		//c += Standardizing();
+
+	return 0;
+	}
+
+
 	/*!
 		this method sets 'result' as the one word of type uint
 
@@ -2258,6 +2286,27 @@ public:
 	}
 
 
+	/*!
+		an operator= for converting from 'Big<another_exp, another_man>' to this class
+	*/
+	template<uint another_exp, uint another_man>
+	Big<exp,man> & operator=(const Big<another_exp, another_man> & value)
+	{
+		FromBig(value);
+
+	return *this;
+	}
+
+
+	/*!
+		a constructor for converting from 'Big<another_exp, another_man>' to this class
+	*/
+	template<uint another_exp, uint another_man>
+	Big(const Big<another_exp, another_man> & value)
+	{
+		FromBig(value);
+	}
+
 	/*!
 		a default constructor
 

ttmath/ttmathparser.h

@@ -1158,6 +1158,35 @@ void BitXor(int sindex, int amount_of_args, ValueType & result)
 	}
 }
 
+
+void Sum(int sindex, int amount_of_args, ValueType & result)
+{
+	if( amount_of_args == 0 )
+		Error( err_improper_amount_of_arguments );
+
+	result = stack[sindex].value;
+
+	for(int i=1 ; i<amount_of_args ; ++i )
+		if( result.Add( stack[ sindex + i*2 ].value ) )
+			Error( err_overflow );
+}	
+
+void Avg(int sindex, int amount_of_args, ValueType & result)
+{
+	if( amount_of_args == 0 )
+		Error( err_improper_amount_of_arguments );
+
+	result = stack[sindex].value;
+
+	for(int i=1 ; i<amount_of_args ; ++i )
+		if( result.Add( stack[ sindex + i*2 ].value ) )
+			Error( err_overflow );
+
+	if( result.Div( amount_of_args ) )
+		Error( err_overflow );
+}	
+
+
 /*!
 	this method returns the value from a user-defined function
 
@@ -1319,6 +1348,8 @@ void CreateFunctionsTable()
 	InsertFunctionToTable(std::string("band"),		&Parser<ValueType>::BitAnd);
 	InsertFunctionToTable(std::string("bor"),		&Parser<ValueType>::BitOr);
 	InsertFunctionToTable(std::string("bxor"),		&Parser<ValueType>::BitXor);
+	InsertFunctionToTable(std::string("sum"),		&Parser<ValueType>::Sum);
+	InsertFunctionToTable(std::string("avg"),		&Parser<ValueType>::Avg);
 }