CmdLine::Option Class Reference

An ArgParam that represents an Option. More...

#include <Option.h>

Inheritance diagram for CmdLine::Option:

Classes
struct	Definition
	This Definition is used to construct an Option. More...

Public Types
enum class	Style { Unix , Windows }
	The style of the Option to use. More...

Public Member Functions
	Option (Definition d)
	Constructs a new Option.
std::string	Name () const override
	Gets the name of the Option.
std::string	Description () const override
	Gets the description of the Option.
std::string	HelpInfo () const override
	Gets help info for the Option.
bool	IsSpecified () const override
	Indicates whether the Option has been specified.
bool	IsMandatory () const override
	Indicates whether the Option is mandatory.
bool	Populate (std::deque< std::string > &args) override
	Populates this Option from an argument queue.
bool	CanPopulate (const std::deque< std::string > &args) const override
	Determines if arguments can populate this Option.
std::size_t	Consumes (const std::deque< std::string > &args) const override
	Gets the number of arguments the Option consumes.
void	Set (Style s)
	Sets the Option::Style of the Option.
std::string	LongName () const
	Gets the long name of the Option.
Public Member Functions inherited from CmdLine::ArgParam
virtual	~ArgParam ()=default
	Destructs an ArgParam.
Public Member Functions inherited from CmdLine::Param
virtual	~Param ()=default
	Destructs a Param.

Detailed Description

An ArgParam that represents an Option.

A command line Option is an ArgParam that specifies an Option for the program. This is the most simple type of Option since it simply indicates whether it is specified when it is populated. Command line arguments that populate and specify options begin with an Option prefix followed by a short name (single character) or long name (multiple characters). What prefix is used depends on the Option::Style used (Unix or Windows). For instance, some programs have an Option that tells the program to produce vebose output. With the Unix Option style, either -v or –verbose could be used to specify such an Option. With the Windows Option style, either /v or /verbose could be used.

Member Enumeration Documentation

Style

enum class CmdLine::Option::Style

strong

The style of the Option to use.

The style of Option determines the style of prefix used to specify and populate the Option at the command line. Unix style indicates that a - prefix should be used for short Option names and – for long Option names. Windows style indicates that a / prefix should be used for both short and long name Options.

Constructor & Destructor Documentation

Option()

CmdLine::Option::Option

(

Definition

d

)

Constructs a new Option.

Parameters

d	The definition used to create the Option.

Invariant

Valid short names characters are alpha numerics and ?.

Valid long name characters are alpha numerics, - and _.

Long names must not start with the option prefix.

Long names must not be longer than 20 characters.

Options must not have both an empty short and long name.

An option can only be specified by successful population.

Exceptions

Param::InvalidDefinition

Doesn't satisfy invariants.

Member Function Documentation

CanPopulate()

bool CmdLine::Option::CanPopulate ( const std::deque< std::string > & args ) const

overridevirtual

Determines if arguments can populate this Option.

Accepts a reference to an argument queue (deque) and determines if the next argument in the queue can populate the Option.

Parameters

args	The argument queue to evaluate.

Returns

True if the arguments can populate, otherwise false.

Implements CmdLine::ArgParam.

Reimplemented in CmdLine::ValueOption.

Consumes()

std::size_t CmdLine::Option::Consumes ( const std::deque< std::string > & args ) const

inlineoverridevirtual

Gets the number of arguments the Option consumes.

An Option should consume exactly 1 argument.

Parameters

args	The argument queue to evaluate.

Returns

The number of arguments the Option will consume.

Implements CmdLine::ArgParam.

Reimplemented in CmdLine::ValueOption.

Description()

std::string CmdLine::Option::Description ( ) const

inlineoverridevirtual

Gets the description of the Option.

The description of the Option is used for generating help.

Returns

The description of the Option.

Implements CmdLine::Param.

HelpInfo()

std::string CmdLine::Option::HelpInfo ( ) const

overridevirtual

Gets help info for the Option.

The help info will include names (short and / or long) and description of the Option when generating help.

Returns

Help info for the Option.

Implements CmdLine::Param.

Reimplemented in CmdLine::ValueOption.

IsMandatory()

bool CmdLine::Option::IsMandatory ( ) const

inlineoverridevirtual

Indicates whether the Option is mandatory.

The command line Parser uses this to determine if an Option must be specified at the command line for parsing to be successful. If a mandatory Option is not specified i.e. the correct command line argument necessary to populate the Option was not supplied, parsing will fail indicating the program was supplied with bad command line arguments.

Returns

True if the Option is mandatory, otherwise false.

Implements CmdLine::Param.

IsSpecified()

bool CmdLine::Option::IsSpecified ( ) const

inlineoverridevirtual

Indicates whether the Option has been specified.

An Option will only indicate it was specified if the Option has been successfully populated by a command line argument. The parser also uses this to determine if a mandatory Option has been specified.

Returns

True if the Option is specified, otherwise false.

Implements CmdLine::Param.

LongName()

std::string CmdLine::Option::LongName ( ) const

inline

Gets the long name of the Option.

The long name of the Option is used to determine if the Option is specified at the command line. It is also used by the Parser to prevent duplicate Options from being added to to it. Finally, the long name is used to generate help info for the Option. This name will always represent the prefixed long name of the option unless the option has no long name, in which case this function will return an empty string.

Returns

The prefixed long name of the Option.

Name()

std::string CmdLine::Option::Name ( ) const

overridevirtual

Gets the name of the Option.

The name of the Option is used to determine if the Option is specified at the command line. It is also used by the Parser to prevent duplicate Options from being added to to it. Finally, the name is used to generate help info for the option. This name will always represent the prefixed short name of the Option unless the Option only has a long name, in which case this function will return the same value as the LongName() method.

Returns

The prefixed name of the Option.

See also

LongName().

Implements CmdLine::Param.

Populate()

bool CmdLine::Option::Populate ( std::deque< std::string > & args )

overridevirtual

Populates this Option from an argument queue.

Accepts a reference to an argument queue (deque) and attempts to populate the Option from the next argument in the queue. Populating the Option marks it as specified. Successful population also consumes the argument from the queue that populated the Option.

Parameters

args	The argument queue to populate the Option with.

Returns

True if population is successful, otherwise false.

Precondition

Size of arguments > 0.

Next argument must be Option's prefixed short or long name.

Postcondition

Option is marked as specified.

Next argument is removed from the queue.

Implements CmdLine::ArgParam.

Reimplemented in CmdLine::ValueOption.

Set()

void CmdLine::Option::Set ( Style s )

inline

Sets the Option::Style of the Option.

Allows the program to change the Option::Style of the Option after it has been created. Alternatively, the Option::Style is set upon construction in the Option::Definition.

Parameters

s	The Option::Style to set

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

• LibCppCmdLine/Option.h