Unit Class Reference

A unit for measurement. More...

#include <Unit.h>

Inheritance diagram for Unit:

Public Member Functions
	Unit (string cat_, string name_, string plural_="", string singular_="", string title_="", bool is_local=true, bool is_builtin=false, bool is_active=true)
	Unit (const Unit *unit)
virtual ExpressionItem *	copy () const
virtual void	set (const ExpressionItem *item)
bool	isSIUnit () const
void	setAsSIUnit ()
void	setSystem (string s_system)
const string &	system () const
bool	useWithPrefixesByDefault () const
void	setUseWithPrefixesByDefault (bool use_with_prefixes)
bool	isCurrency () const
virtual string	print (bool plural_, bool short_, bool use_unicode=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
virtual const string &	plural (bool return_singular_if_no_plural=true, bool use_unicode=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
virtual const string &	singular (bool return_abbreviation_if_no_singular=true, bool use_unicode=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
virtual const string &	abbreviation (bool return_singular_if_no_abbreviation=true, bool use_unicode=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
virtual bool	isUsedByOtherUnits () const
virtual Unit *	baseUnit () const
virtual MathStructure &	convertToBaseUnit (MathStructure &mvalue, MathStructure &mexp) const
virtual MathStructure &	convertFromBaseUnit (MathStructure &mvalue, MathStructure &mexp) const
virtual MathStructure &	convertToBaseUnit (MathStructure &mvalue) const
virtual MathStructure &	convertFromBaseUnit (MathStructure &mvalue) const
virtual MathStructure	convertToBaseUnit () const
virtual MathStructure	convertFromBaseUnit () const
virtual int	baseExponent (int exp=1) const
virtual int	type () const
virtual int	subtype () const
virtual bool	isChildOf (Unit *u) const
virtual bool	isParentOf (Unit *u) const
virtual bool	hasComplexRelationTo (Unit *u) const
bool	convert (Unit *u, MathStructure &mvalue, MathStructure &exp) const
bool	convert (Unit *u, MathStructure &mvalue) const
MathStructure	convert (Unit *u, bool *converted=NULL) const
Public Member Functions inherited from ExpressionItem
	ExpressionItem (string cat_, string name_, string title_="", string descr_="", bool is_local=true, bool is_builtin=false, bool is_active=true)
virtual bool	destroy ()
bool	isRegistered () const
void	setRegistered (bool is_registered)
	For internal use.
virtual const string &	name (bool use_unicode=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
virtual const string &	referenceName () const
virtual const ExpressionName &	preferredName (bool abbreviation=false, bool use_unicode=false, bool plural=false, bool reference=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
virtual const ExpressionName &	preferredInputName (bool abbreviation=false, bool use_unicode=false, bool plural=false, bool reference=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
virtual const ExpressionName &	preferredDisplayName (bool abbreviation=false, bool use_unicode=false, bool plural=false, bool reference=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
virtual const ExpressionName &	getName (size_t index) const
virtual void	setName (const ExpressionName &ename, size_t index=1, bool force=true)
virtual void	setName (string sname, size_t index, bool force=true)
virtual void	addName (const ExpressionName &ename, size_t index=0, bool force=true)
virtual void	addName (string sname, size_t index=0, bool force=true)
virtual size_t	countNames () const
virtual void	clearNames ()
virtual void	clearNonReferenceNames ()
virtual void	removeName (size_t index)
virtual size_t	hasName (const string &sname, bool case_sensitive=true) const
virtual size_t	hasNameCaseSensitive (const string &sname) const
virtual const ExpressionName &	findName (int abbreviation=-1, int use_unicode=-1, int plural=-1, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
virtual const string &	title (bool return_name_if_no_title=true, bool use_unicode=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
virtual void	setTitle (string title_)
virtual const string &	description () const
virtual void	setDescription (string descr_)
virtual const string &	category () const
virtual void	setCategory (string cat_)
virtual bool	hasChanged () const
virtual void	setChanged (bool has_changed)
virtual bool	isLocal () const
virtual bool	setLocal (bool is_local=true, int will_be_active=-1)
virtual bool	isBuiltin () const
virtual bool	isApproximate () const
virtual void	setApproximate (bool is_approx=true)
virtual int	precision () const
virtual void	setPrecision (int prec)
virtual bool	isActive () const
virtual void	setActive (bool is_active)
virtual bool	isHidden () const
virtual void	setHidden (bool is_hidden)
virtual int	refcount () const
virtual void	ref ()
virtual void	unref ()
virtual void	ref (ExpressionItem *o)
virtual void	unref (ExpressionItem *o)
virtual ExpressionItem *	getReferencer (size_t index=1) const
virtual bool	changeReference (ExpressionItem *o_from, ExpressionItem *o_to)

Protected Attributes
string	ssystem
bool	b_si
bool	b_use_with_prefixes
Protected Attributes inherited from ExpressionItem
string	scat
string	stitle
string	sdescr
bool	b_local
bool	b_changed
bool	b_builtin
bool	b_approx
bool	b_active
bool	b_registered
bool	b_hidden
bool	b_destroyed
int	i_ref
int	i_precision
vector< ExpressionItem * >	v_refs
vector< ExpressionName >	names

Detailed Description

A unit for measurement.

The Unit class both represents a base unit and is the base class for other unit types. Base units are units defined as basis for other units. Meters and seconds are typical base units.

For base units, a name is all that is needed. Base units do however normally have three different names defined for use in expressions - abbreviation (ex. "m"), singular ("meter") and plural ("meters").

Member Function Documentation

bool Unit::convert	(	Unit *	u,
		MathStructure &	mvalue,
		MathStructure &	exp
	)		const

Converts a value from specified unit and exponent to this unit. value * (unit^exponent) = new value * (this^new exponent) This function cannot convert to or from CompositeUnit.

Parameters

	u	Unit to convert from.
[in,out]	mvalue	Quantity value.
[in,out]	exp	Exponent.

Returns

true if the value was successfully converted.

bool Unit::convert	(	Unit *	u,
		MathStructure &	mvalue
	)		const

Converts a value from specified unit and exponent to this unit. value * unit = new value * this This function cannot convert to or from CompositeUnit.

Parameters

	u	Unit to convert from.
[in,out]	mvalue	Quantity value.

Returns

true if the value was successfully converted.

virtual bool Unit::isChildOf ( Unit *  u ) const

virtual

If specified unit is a base unit for this unit, directly or with other units in between. Equivalent to u->isParentOf(this).

Reimplemented in AliasUnit.

bool Unit::isCurrency

(

)

const

Returns if the unit is a currency (Euro is base unit).

Returns

true if the unit is a currency.

virtual bool Unit::isParentOf ( Unit *  u ) const

virtual

If this unit is a base unit for specified unit, directly or with other units in between. Equivalent to u->isChildOf(this).

Reimplemented in AliasUnit.

bool Unit::isSIUnit

(

)

const

Returns if the unit is part of the SI standard.

Returns

true if the unit is part of the SI standard.

virtual string Unit::print ( bool  plural_, bool  short_, bool  use_unicode = false, bool(*)(const char *, void *)  can_display_unicode_string_function = NULL, void *  can_display_unicode_string_arg = NULL  ) const

virtual

Returns a display string representing the unit in an expression.

Equivalent to preferredName() for Unit and AliasUnit, but closer to MathStructure::print() for CompositeUnit (prints out base expression).

Reimplemented in CompositeUnit, and AliasUnit_Composite.

void Unit::setAsSIUnit

(

)

State that the unit is part of the SI standard. Sets system to "SI".

void Unit::setSystem

(

string

s_system

)

Sets which system/standard ("SI", "CGS", etc.) the unit is part of. Setting system to "SI" (case-insensitive), is equivalent to setAsSIUnit().

void Unit::setUseWithPrefixesByDefault

(

bool

use_with_prefixes

)

Sets wether prefixes are approriate with this unit or not.

virtual int Unit::subtype ( ) const

virtual

Returns the subtype of the unit, corresponding to which subsubclass the object belongs to.

Returns

UnitSubtype.

Implements ExpressionItem.

Reimplemented in CompositeUnit, and AliasUnit.

const string& Unit::system

(

)

const

Returns the system/standard that the unit is part of.

Returns

System string.

virtual int Unit::type ( ) const

virtual

Returns the type of the expression item, corresponding to which subclass the object belongs to.

Returns

ExpressionItemType.

Implements ExpressionItem.

bool Unit::useWithPrefixesByDefault

(

)

const

Returns wether prefixes should be used with this unit or not.

Returns

true if the prefixes is appropriate for this unit.

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

• libqalculate/Unit.h