RWExchangeRateTable Class Reference
[Currency Conversions]

Stores exchange rates as unique pairs of source and target currencies. More...

#include <rw/currency/exchgratetbl.h>

List of all members.

Public Member Functions
	RWExchangeRateTable ()
	RWExchangeRateTable (const RWExchangeRateTable &t)
RWExchangeRateTable &	operator= (const RWExchangeRateTable &)
bool	initialize (std::istream &strm)
bool	findExchangeRate (const RWCString &sourceMnemonic, const RWCString &targetMnemonic, RWExchangeRate &rate) const
bool	findConversionFactor (const RWCString &sourceMnemonic, const RWCString &targetMnemonic, double &factor) const
bool	contains (const RWCString &source, const RWCString &target) const
bool	contains (const RWExchangeRate &rate) const
size_t	entries () const
RWTValSlist< RWExchangeRate >	getAllExchangeRates () const
bool	add (const RWExchangeRate &exchangeRate)
bool	add (const RWCString &source, const RWCString &target, double convFactor)
bool	remove (const RWExchangeRate &rate)
bool	remove (const RWCString &source, const RWCString &target)
bool	setConversionFactor (const RWCString &source, const RWCString &target, double convFactor)
void	clear ()
void	saveOn (RWvostream &) const
void	saveOn (RWFile &) const
void	restoreFrom (RWvistream &)
void	restoreFrom (RWFile &)
Static Public Attributes
static const RWCString	sourceTag
static const RWCString	targetTag
static const RWCString	conversionFactorTag
Related Functions
(Note that these are not member functions.)
RWvostream &	operator<< (RWvostream &s, const RWExchangeRateTable &t)
RWvistream &	operator>> (RWvistream &s, RWExchangeRateTable &t)
RWFile &	operator<< (RWFile &f, const RWExchangeRateTable &t)
RWFile &	operator>> (RWFile &f, RWExchangeRateTable &t)

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Detailed Description

Class RWExchangeRateTable stores exchange rates as unique pairs of source and target currencies. No two exchange rates in the table have the same source-target currency pair.

The RWExchangeRateTable class can be initialized from a stream, in particular, from an std::ifstream (file). The format for the stream is:

 BEGIN_EXCHANGE
 source=
 target=
 rate=
 END_EXCHANGE

Synopsis

 #include<rw/currency/exchgratetbl.h>
 std::ifstream strm("exchange_rates.txt");
 RWExchangeRateTable rates;
 rates.initialize(strm);

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Constructor & Destructor Documentation

RWExchangeRateTable::RWExchangeRateTable

(

)

Default constructor. Constructs an empty exchange rate table.

RWExchangeRateTable::RWExchangeRateTable

(

const RWExchangeRateTable &

t

)

Copy constructor. Copies contents of t to self.

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Member Function Documentation

bool RWExchangeRateTable::add	(	const RWCString &	source,
		const RWCString &	target,
		double	convFactor
	)			[inline]

Adds an exchange rate object with the given source, target and convFactor to the table if none exists, and returns true. If the table already contains an exchange rate with the given source and target, this function returns false without adding to the table.

bool RWExchangeRateTable::add

(

const RWExchangeRate &

exchangeRate

)

Adds exchangeRate to the table and returns true if there is no exchange rate in the table with the same source and target currency as exchangeRate. If the table already contains an exchange rate with the same source and target currencies as exchangeRate exists, the function returns false without adding to the table.

void RWExchangeRateTable::clear

(

)

Removes all exchange rates from the table.

bool RWExchangeRateTable::contains

(

const RWExchangeRate &

rate

)

const

Returns true if the table contains the given rate. Returns false otherwise.

bool RWExchangeRateTable::contains	(	const RWCString &	source,
		const RWCString &	target
	)			const

Returns true if the table contains a rate for the given source and target currencies. Returns false otherwise.

size_t RWExchangeRateTable::entries

(

)

const

Returns the number of exchange rates in the table.

bool RWExchangeRateTable::findConversionFactor	(	const RWCString &	sourceMnemonic,
		const RWCString &	targetMnemonic,
		double &	factor
	)			const

Searches the exchange rate table to find the exchange rate for converting money with currency specified by sourceMnemonic into money in currency specified by targetMnemonic. If the rate is found, the conversion factor is placed in factor and the function returns true. If the rate is not found, the function returns false and factor is unchanged.

bool RWExchangeRateTable::findExchangeRate	(	const RWCString &	sourceMnemonic,
		const RWCString &	targetMnemonic,
		RWExchangeRate &	rate
	)			const

Searches the exchange rate table to determine whether an exchange rate for the currency specified by sourceMnemonic into the currency specified by targetMnemonic exists. If an exchange rate is found, it is placed in rate and the function returns true. If an exchange rate is not found, the function returns false and rate is unchanged.

RWTValSlist<RWExchangeRate> RWExchangeRateTable::getAllExchangeRates

(

)

const

Returns a list of all the exchange rates in the table.

bool RWExchangeRateTable::initialize

(

std::istream &

strm

)

Initializes an exchange rate table from the information in strm. Returns false if there is an error in the stream format.

An exchange rate specification begins with the token BEGIN_EXCHANGE on a line by itself. Each attribute of the exchange rate follows, specified as a name/value pair, one per line. The name/value separator is the equal sign `='. The end of an exchange rate specification is indicated by the token END_EXCHANGE. Comment lines start with a # character and are automatically skipped. For example:

 # DZD/CAD (Algeria to Canada)
 BEGIN_EXCHANGE
 source=CAD
 target=DZD
 rate=35.5
 END_EXCHANGE
 .
 .
 .

Name matching is case-insensitive. Valid names for the name/value pairs are:

 source = RWExchangeRateTable::sourceTag
 target = RWExchangeRateTable::targetTag
 rate = RWExchangeRateTable::conversionFactorTag

RWExchangeRateTable& RWExchangeRateTable::operator=

(

const RWExchangeRateTable &

)

Assignment operator.

bool RWExchangeRateTable::remove	(	const RWCString &	source,
		const RWCString &	target
	)

Removes the exchange rate for the given source and target currencies. If no such exchange rate was found, this function returns false. Otherwise, it returns true.

bool RWExchangeRateTable::remove

(

const RWExchangeRate &

rate

)

Removes the given exchange rate. If no such exchange rate was found, this function returns false. Otherwise, it returns true.

void RWExchangeRateTable::restoreFrom

(

RWFile &

)

Restore from an RWFile.

void RWExchangeRateTable::restoreFrom

(

RWvistream &

)

Restore from a virtual stream.

void RWExchangeRateTable::saveOn

(

RWFile &

)

const

Persists to an RWFile.

void RWExchangeRateTable::saveOn

(

RWvostream &

)

const

Persists to a virtual stream.

bool RWExchangeRateTable::setConversionFactor	(	const RWCString &	source,
		const RWCString &	target,
		double	convFactor
	)

Searches the exchange rate table for an exchange rate with the same source and target currencies as source and target. If one exists, this function replaces its conversion factor with convFactor, and returns true. If one does not exist, this function returns false.

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Friends And Related Function Documentation

RWFile & operator<<	(	RWFile &	f,
		const RWExchangeRateTable &	t
	)			[related]

Saves the object to a RWFile.

RWvostream & operator<<	(	RWvostream &	s,
		const RWExchangeRateTable &	t
	)			[related]

Saves the object to a virtual stream.

RWFile & operator>>	(	RWFile &	f,
		RWExchangeRateTable &	t
	)			[related]

Restores a object from a RWFile.

RWvistream & operator>>	(	RWvistream &	s,
		RWExchangeRateTable &	t
	)			[related]

Restores a object from a virtual stream.

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Member Data Documentation

const RWCString RWExchangeRateTable::conversionFactorTag [static]

Used for the names in the name/value pairs described in the RWExchangeRateTable::initialize() member function.

const RWCString RWExchangeRateTable::sourceTag [static]

Used for the names in the name/value pairs described in the RWExchangeRateTable::initialize() member function.

const RWCString RWExchangeRateTable::targetTag [static]

Used for the names in the name/value pairs described in the RWExchangeRateTable::initialize() member function.