Type Parameters:

T - the type of a possible value (i.e., the type of the option)

All Known Implementing Classes:

AbstractParameter, ClassListParameter, ClassParameter, DoubleArrayListParameter, DoubleListParameter, DoubleParameter, DynamicParameters.RemainingOptions, EnumParameter, FileListParameter, FileParameter, Flag, IntGeneratorParameter, IntListParameter, IntParameter, ListParameter, LongParameter, NumberParameter, ObjectListParameter, ObjectParameter, PatternParameter, RandomParameter, StringParameter
```
public interface Parameter<T>
```
Interface for the parameter of a class.
A parameter is defined as an option having a specific value.
See the elki.utilities.optionhandling package for documentation!

Since:

0.1

Author:

Steffi Wanka, Erich Schubert

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Parameter<T>`	`addConstraint(ParameterConstraint<? super T> constraint)`	Add an additional constraint.
`java.lang.StringBuilder`	`describeValues(java.lang.StringBuilder description)`	Describe the valid values.
`java.util.List<ParameterConstraint<? super T>>`	`getConstraints()`	Get the parameter constraints.
`T`	`getDefaultValue()`	Returns the default value of the parameter.
`java.lang.String`	`getDefaultValueAsString()`	Get the default value as string.
`OptionID`	`getOptionID()`	Return the OptionID of this option.
`java.lang.String`	`getSyntax()`	Returns a string representation of the parameter's type (e.g., an `IntParameter` should return `<int>`).
`T`	`getValue()`	Returns the value of the option.
`java.lang.String`	`getValueAsString()`	Get the value as string.
`boolean`	`hasDefaultValue()`	Checks if this parameter has a default value.
`boolean`	`isDefined()`	Returns true if the value of the option is defined, false otherwise.
`boolean`	`isOptional()`	Checks if this parameter is an optional parameter.
`boolean`	`isValid(java.lang.Object obj)`	Checks if the given argument is valid for this option.
`Parameter<T>`	`setDefaultValue(T defaultValue)`	Sets the default value of this parameter.
`Parameter<T>`	`setOptional(boolean opt)`	Specifies if this parameter is an optional parameter.
`void`	`setValue(java.lang.Object obj)`	Sets the value of the option.
`boolean`	`tookDefaultValue()`	Checks if the default value of this parameter was taken as the actual parameter value.
`boolean`	`tryDefaultValue()`	Handle default values for a parameter.

- Method Detail
  - setDefaultValue
```
Parameter<T> setDefaultValue(T defaultValue)
```
    Sets the default value of this parameter.
    
    Parameters:
    
    defaultValue - default value of this parameter
    
    Returns:
    
    the parameter itself, for chaining
  - hasDefaultValue
```
boolean hasDefaultValue()
```
    Checks if this parameter has a default value.
    
    Returns:
    
    true, if this parameter has a default value, false otherwise
  - tryDefaultValue
```
boolean tryDefaultValue()
                 throws UnspecifiedParameterException
```
    Handle default values for a parameter.
    
    Returns:
    
    Return code: true if it has a default value, false if it is optional without a default value. Exception if it is a required parameter!
    
    Throws:
    
    UnspecifiedParameterException - If the parameter requires a value
  - setOptional
```
Parameter<T> setOptional(boolean opt)
```
    Specifies if this parameter is an optional parameter.
    
    Parameters:
    
    opt - true if this parameter is optional, false otherwise
    
    Returns:
    
    the parameter itself, for chaining
  - isOptional
```
boolean isOptional()
```
    Checks if this parameter is an optional parameter.
    
    Returns:
    
    true if this parameter is optional, false otherwise
  - tookDefaultValue
```
boolean tookDefaultValue()
```
    Checks if the default value of this parameter was taken as the actual parameter value.
    
    Returns:
    
    true, if the default value was taken as actual parameter value, false otherwise
  - isDefined
```
boolean isDefined()
```
    Returns true if the value of the option is defined, false otherwise.
    
    Returns:
    
    true if the value of the option is defined, false otherwise.
  - getDefaultValue
```
T getDefaultValue()
```
    Returns the default value of the parameter.
    If the parameter has no default value, the method returns null.
    
    Returns:
    
    the default value of the parameter, null if the parameter has no default value.
  - getOptionID
```
OptionID getOptionID()
```
    Return the OptionID of this option.
    
    Returns:
    
    Option ID
  - setValue
```
void setValue(java.lang.Object obj)
       throws ParameterException
```
    Sets the value of the option.
    
    Parameters:
    
    obj - the option's value to be set
    
    Throws:
    
    ParameterException - if the given value is not a valid value for this option.
  - getValue
```
T getValue()
```
    Returns the value of the option.
    You should use either Parameterization.grab(elki.utilities.optionhandling.parameters.Parameter<?>) or isDefined() to test if getValue() will return a well-defined value.
    
    Returns:
    
    the option's value.
  - isValid
```
boolean isValid(java.lang.Object obj)
         throws ParameterException
```
    Checks if the given argument is valid for this option.
    
    Parameters:
    
    obj - option value to be checked
    
    Returns:
    
    true, if the given value is valid for this option
    
    Throws:
    
    ParameterException - if the given value is not a valid value for this option.
  - getSyntax
```
java.lang.String getSyntax()
```
    Returns a string representation of the parameter's type (e.g., an IntParameter should return <int>).
    
    Returns:
    
    a string representation of the parameter's type
  - getValueAsString
```
java.lang.String getValueAsString()
```
    Get the value as string. May return null
    
    Returns:
    
    Value as string
  - getDefaultValueAsString
```
java.lang.String getDefaultValueAsString()
```
    Get the default value as string.
    
    Returns:
    
    default value
  - describeValues
```
java.lang.StringBuilder describeValues(java.lang.StringBuilder description)
```
    Describe the valid values.
    
    Parameters:
    
    description - Buffer to append to
    
    Returns:
    
    Buffer
  - addConstraint
```
Parameter<T> addConstraint(ParameterConstraint<? super T> constraint)
```
    Add an additional constraint.
    
    Parameters:
    
    constraint - Constraint to add.
    
    Returns:
    
    the parameter itself, for chaining
  - getConstraints
```
java.util.List<ParameterConstraint<? super T>> getConstraints()
```
    Get the parameter constraints.
    
    Returns:
    
    Parameter constraints

Interface Parameter<T>

Method Summary

Method Detail

setDefaultValue

hasDefaultValue

tryDefaultValue

setOptional

isOptional

tookDefaultValue

isDefined

getDefaultValue

getOptionID

setValue

getValue

isValid

getSyntax

getValueAsString

getDefaultValueAsString

describeValues

addConstraint

getConstraints