Param.h

Classes

Param -- A simple keyword/value pair with internal help Strings. (full description)

class Param

Interface

Public Members

Param (const String& key, const String& value, const String& help, const String& type, const String& range, const String& unit)

Param (const Param&)

~Param()

Param& operator= (const Param&)

Bool operator== (const Param&) const

friend ostream& operator<< (ostream&, const Param& p)

friend istream& operator>> (istream&, Param& p)

friend AipsIO& operator<< (AipsIO&, const Param& p)

friend AipsIO& operator>> (AipsIO&, Param& p)

Double getDouble (Bool do_prompt=False) const

Block<Double> getDoubleArray (Bool do_prompt=False) const

Int getInt (Bool do_prompt=False) const

Block<Int> getIntArray (Bool do_prompt=False) const

const String& getString (Bool do_prompt=False) const

Block<String> getStringArray (Bool do_prompt=False) const

Bool getBool (Bool do_prompt=False) const

const String& get() const

const String& getHelp() const

const String& getKey() const

String keyVal() const

const String& getType() const

const String& getRange() const

const String& getUnit() const

Bool put (const String& a_value)

void setSystem (Bool val)

Bool isSystem() const

void setIndex (Int inx)

Int getIndex() const

Description

Review Status

Reviewed By:

UNKNOWN

Date Reviewed:

before2004/08/25

Programs:

Tests:

tParam.cc

Prerequisite

none noted

Etymology

The Param class name is a shortening of "parameter" and is indicative of the class being designed as a keyword/value pair relating to command line arguments. The existing Keyword class does a much better job for most other purposes.

Synopsis

The Param is constructed with all arguments being Strings. This is a reflection of the C-type command line argument method of passing an integer (argc or argument count) and an array of pointers to characters (argv or argument vector.) If "char* argv[]" is broken into its individual arguments they may be used to fill a Param. The constructor pairs up a "key" to a value. A help String argument is provided to assist in prompted filling of Param values. The expected return type may be entered as well as a range of potential values. Finally, the units of the value are also specified. The intent is to provide a well documented value and a "key" by which to "call" it.

The "getWhatever" member functions of Param convert the internal Strings into the desired output data type. The Strings themselves may also be returned.

Example

    // we will create a Param which contains the boundary for an iteration loop.
    String key("IterBound");
    // give "IterBound" a default value
    String value("200");
    // a help String for prompting
    String help("The Boundary value for the chutzpah iterator.");
    // The expected return type is an integer
    String type("Int");
    // The range of "legal" values 
    String range("10-10000");
    // the units of the value
    String unit("unitless"):
    // Now we may build our Param
    Param PleaseDontTouchMeThere(key, value, help, type, range, unit);
    // to retrieve the value we use the GetInt function
    for (Int i=0, i<PleaseDontTouchMeThere.getInt(); i++, chutzpah++);

Motivation

The Param class was an early attempt at keywords within AIPS++. They have become obsolete but hang on due to their relationship with the Input class.

To Do

fix the GetStringArray() function
convert from Block to Array as return values.
replace entirely with AIPS++ Keywords?

Member Description

Param()

constructors and destructor default constructor

Param (const String& key, const String& value, const String& help, const String& type, const String& range, const String& unit)

normal constructor with optional value and help strings

Param (const Param&)

copy constructor

~Param()

destructor

Param& operator= (const Param&)

assignment operator

Bool operator== (const Param&) const

Equality comparitor

This function ALWAYS returns false. I have no idea why it was designed to do this.

friend ostream& operator<< (ostream&, const Param& p)
friend istream& operator>> (istream&, Param& p)
friend AipsIO& operator<< (AipsIO&, const Param& p)
friend AipsIO& operator>> (AipsIO&, Param& p)

I/O operators

Double getDouble (Bool do_prompt=False) const

get a double parameter value; prompt if switch is TRUE

Block<Double> getDoubleArray (Bool do_prompt=False) const

get a Block parameter value; prompt if switch is TRUE

Int getInt (Bool do_prompt=False) const

get an Int parameter value; prompt if switch is TRUE

Block<Int> getIntArray (Bool do_prompt=False) const

get an Block parameter value; prompt if switch is TRUE

const String& getString (Bool do_prompt=False) const

get a String parameter value; prompt if switch is TRUE

Block<String> getStringArray (Bool do_prompt=False) const

get a Block parameter value; prompt if switch is TRUE

Bool getBool (Bool do_prompt=False) const

get a Boolean parameter value; prompt if switch is TRUE

const String& get() const

get parameter value as a string

const String& getHelp() const

get parameter help string

const String& getKey() const

get parameter name

String keyVal() const

get the string `key = value' for the parameter

const String& getType() const

get the type of a parameter

const String& getRange() const

get the valid range of a parameter

const String& getUnit() const

get the units of a parameter

Bool put (const String& a_value)

set new parameter value; return FALSE if invalid value

void setSystem (Bool val)

set a parameter as a system parameter

Bool isSystem() const

check if a parameter is a system parameter

void setIndex (Int inx)

set an index for a program parameter

Int getIndex() const

get the index of a parameter