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KeyVal Class Reference

The KeyVal class is designed to simplify the process of allowing a user to specify keyword/value associations to a C++ program. More...

#include <keyval.h>

Inheritance diagram for KeyVal

[legend]Collaboration diagram for KeyVal:

[legend]List of all members.

Public Types
enum	{ MaxKeywordLength = 256 }
enum	KeyValError {   OK, HasNoValue, WrongType, UnknownKeyword,   OperationFailed }
Public Methods
virtual	~KeyVal ()
int	exists (const char *)
	This takes as its only argument a keyword. More...
int	count (const char *=0)
	If the value of a keyword is an array, then return its length. More...
Ref<KeyValValue>	value (const char *=0, const KeyValValue &def=KeyValValue())
	Return the value associated with the keyword.
int	booleanvalue (const char *key=0, const KeyValValue &def=KeyValValueboolean())
	Returns the boolean value (0 = false, 1 = true) of key.
double	doublevalue (const char *key=0, const KeyValValue &def=KeyValValuedouble())
	Returns the double value of key.
float	floatvalue (const char *key=0, const KeyValValue &def=KeyValValuefloat())
	Returns the float value of key.
char	charvalue (const char *key=0, const KeyValValue &def=KeyValValuechar())
	Returns the char value of key.
int	intvalue (const char *key=0, const KeyValValue &def=KeyValValueint())
	Returns the int value of key.
char*	pcharvalue (const char *key=0, const KeyValValue &def=KeyValValuepchar())
	Returns a copy of the string representation of the key's value. More...
Ref<DescribedClass>	describedclassvalue (const char *key=0, const KeyValValue &def=KeyValValueRefDescribedClass())
	Returns a reference to an object of type DescribedClass.
int	exists (const char *,int)
int	count (const char *,int)
int	booleanvalue (const char *,int, const KeyValValue &def=KeyValValueboolean())
double	doublevalue (const char *key, int, const KeyValValue &def=KeyValValuedouble())
float	floatvalue (const char *key, int, const KeyValValue &def=KeyValValuefloat())
char	charvalue (const char *key, int, const KeyValValue &def=KeyValValuechar())
int	intvalue (const char *key, int, const KeyValValue &def=KeyValValueint())
char*	pcharvalue (const char *key, int, const KeyValValue &def=KeyValValuepchar())
Ref<DescribedClass>	describedclassvalue (const char *key, int, const KeyValValue &def=KeyValValueRefDescribedClass())
int	exists (int i)
int	count (int i)
int	booleanvalue (int i, const KeyValValue &def=KeyValValueboolean())
double	doublevalue (int i, const KeyValValue &def=KeyValValuedouble())
float	floatvalue (int i, const KeyValValue &def=KeyValValuefloat())
char	charvalue (int i, const KeyValValue &def=KeyValValuechar())
int	intvalue (int i, const KeyValValue &def=KeyValValueint())
char*	pcharvalue (int i, const KeyValValue &def=KeyValValuepchar())
Ref<DescribedClass>	describedclassvalue (int i, const KeyValValue &def=KeyValValueRefDescribedClass())
int	exists (const char *,int, int)
int	count (const char *,int, int)
int	booleanvalue (const char *,int, int, const KeyValValue &def=KeyValValueboolean())
double	doublevalue (const char *key, int, int, const KeyValValue &def=KeyValValuedouble())
float	floatvalue (const char *key, int, int, const KeyValValue &def=KeyValValuefloat())
char	charvalue (const char *key, int, int, const KeyValValue &def=KeyValValuechar())
int	intvalue (const char *key, int, int, const KeyValValue &def=KeyValValueint())
char*	pcharvalue (const char *key, int, int, const KeyValValue &def=KeyValValuepchar())
Ref<DescribedClass>	describedclassvalue (const char *key, int, int, const KeyValValue &def=KeyValValueRefDescribedClass())
int	exists (int i, int j)
int	count (int i, int j)
int	booleanvalue (int i, int j, const KeyValValue &def=KeyValValueboolean())
double	doublevalue (int i, int j, const KeyValValue &def=KeyValValuedouble())
float	floatvalue (int i, int j, const KeyValValue &def=KeyValValuefloat())
char	charvalue (int i, int j, const KeyValValue &def=KeyValValuechar())
int	intvalue (int i, int j, const KeyValValue &def=KeyValValueint())
char*	pcharvalue (int i, int j, const KeyValValue &def=KeyValValuepchar())
Ref<DescribedClass>	describedclassvalue (int i, int j, const KeyValValue &def=KeyValValueRefDescribedClass())
int	Va_exists (const char *,int,...)
int	Va_count (const char *,int,...)
int	Va_booleanvalue (const char *,int,...)
double	Va_doublevalue (const char *key, int,...)
float	Va_floatvalue (const char *key, int,...)
char	Va_charvalue (const char *key, int,...)
int	Va_intvalue (const char *key, int,...)
char*	Va_pcharvalue (const char *key, int,...)
Ref<DescribedClass>	Va_describedclassvalue (const char *key, int,...)
KeyValError	error ()
	Return the current error condition.
const char*	errormsg (KeyValError err)
	Return a textual representation of err.
const char*	errormsg ()
	Return a textual representation of the current error.
virtual void	errortrace (std::ostream &fp=ExEnv::err())
virtual void	dump (std::ostream &fp=ExEnv::err())
virtual void	print_unseen (std::ostream &fp=ExEnv::out())
	Print keywords that were never looked at, if possible.
virtual int	have_unseen ()
	Return 1 if there were unseen keywords, 0 if there are none, or -1 this keyval doesn't keep track of unseen keywords.
void	verbose (int v)
	Control printing of assignments.
int	verbose () const
	Returns nonzero if assignments are printed.
Protected Methods
	KeyVal ()
void	seterror (KeyValError err)
	Set the current error condition.
void	seterror (KeyValValue::KeyValValueError err)
	Set the current error condition.
virtual int	key_exists (const char *)=0
	Ultimately called by exists.
virtual int	key_count (const char *=0)
	Ultimately called by count.
virtual Ref<KeyValValue>	key_value (const char *, const KeyValValue &def)=0
	Ultimately called by value.
virtual int	key_booleanvalue (const char *,const KeyValValue &def)
	Ultimately called by booleanvalue.
virtual double	key_doublevalue (const char *key, const KeyValValue &def)
	Ultimately called by doublevalue.
virtual float	key_floatvalue (const char *key, const KeyValValue &def)
	Ultimately called by floatvalue.
virtual char	key_charvalue (const char *key, const KeyValValue &def)
	Ultimately called by charvalue.
virtual int	key_intvalue (const char *key, const KeyValValue &def)
	Ultimately called by intvalue.
virtual char*	key_pcharvalue (const char *key, const KeyValValue &def)
	Ultimately called by pcharvalue.
virtual Ref<DescribedClass>	key_describedclassvalue (const char *key, const KeyValValue &def)
	Ultimately called by describedclassvalue.
Protected Attributes
int	verbose_
Friends
class	AggregateKeyVal
class	PrefixKeyVal

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Detailed Description

The KeyVal class is designed to simplify the process of allowing a user to specify keyword/value associations to a C++ program.

A flexible input style and ease of use for the programmer is achieved with this method. Keywords are represented by null terminated character arrays. The keywords are organized hierarchially, in a manner similar to the way that many file systems are organized. One character is special, ":", which is used to separate the various hierarchial labels, which are referred to as "segments", in the keyword.

A convention for specifying arrays is provided by KeyVal. Each index of the array is given by appending a segment containing the character representation of the index. Thus, "array:3:4" would be a the keyword corresponding to fourth row and fifth column of "array", since indexing starts at zero.

To allow the KeyVal class to have associations that can represent data for classes, the keyword can be associated with a class as well as a value. This permits polymorphic data to be unambiguously represented by keyword/value associations. Most use of KeyVal need not be concerned with this.

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Member Function Documentation

int KeyVal::count ( const char * = 0 )

If the value of a keyword is an array, then return its length. If no arguments are given then the top level will be checked to see if it is an array and, if so, the number of elements will be counted.

int KeyVal::exists ( const char * )

This takes as its only argument a keyword. Returns 1 if the keyword has a value and 0 otherwise.

char * KeyVal::pcharvalue ( const char * key = 0, const KeyValValue & def = KeyValValuepchar() )

Returns a copy of the string representation of the key's value. Storage for the copy is obtained with new.

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The documentation for this class was generated from the following file:

• keyval.h

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