io.github.privacystreams.commons.list

Class ListOperators

java.lang.Object

io.github.privacystreams.commons.list.ListOperators

@PSOperatorWrapper
public class ListOperators
extends java.lang.Object

A helper class to access list-related functions.

Constructor Summary

Constructors

Constructor and Description
ListOperators()

Method Summary

Modifier and Type	Method and Description
static Function<Item,java.lang.Boolean>	contains(java.lang.String listField, java.lang.Object value) Check whether the list specified by a field contains a given value.
static Function<Item,java.lang.Integer>	count(java.lang.String listField) Count the number of elements in the list specified by a field.
static <TValue> Function<Item,java.lang.Boolean>	intersects(java.lang.String listField, TValue[] listToCompare) Check whether the list specified by a field intersects with a given list.
static Function<Item,java.lang.Number>	max(java.lang.String numListField) Get the max value of a field in the stream.
static Function<Item,java.lang.Double>	mean(java.lang.String numListField) Calculate the average of the numbers specified by a field.
static Function<Item,java.lang.Number>	median(java.lang.String numListField) Get the median value of a field in the stream.
static Function<Item,java.lang.Number>	min(java.lang.String numListField) Get the min value of a field in the stream.
static Function<Item,java.lang.Number>	mode(java.lang.String numListField) Get the mode value of a field in the stream.
static Function<Item,java.lang.Double>	range(java.lang.String numListField) Calculate the range of the numbers specified by a field.
static Function<Item,java.lang.Double>	rms(java.lang.String numListField) Calculate the RMS (root mean square) of the numbers specified by a field.
static Function<Item,java.lang.Double>	sum(java.lang.String numListField) Calculate the sum of the numbers specified by a field.
static Function<Item,java.lang.Double>	variance(java.lang.String numListField) Calculate the variance of the numbers specified by a field.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ListOperators

public ListOperators()

Method Detail

contains

public static Function<Item,java.lang.Boolean> contains(java.lang.String listField,
                                                        java.lang.Object value)

Check whether the list specified by a field contains a given value.

Parameters:

listField - the name of the list field

value - the value to check if is in the list

Returns:

the predicate

intersects

public static <TValue> Function<Item,java.lang.Boolean> intersects(java.lang.String listField,
                                                                   TValue[] listToCompare)

Check whether the list specified by a field intersects with a given list.

Parameters:

listField - the name of the list field

listToCompare - the list to compare

Returns:

the predicate

count

public static Function<Item,java.lang.Integer> count(java.lang.String listField)

Count the number of elements in the list specified by a field.

Parameters:

listField - the name of the field to count

Returns:

the function.

range

public static Function<Item,java.lang.Double> range(java.lang.String numListField)

Calculate the range of the numbers specified by a field. The list elements must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no number in the list), the result will be null.

Parameters:

numListField - the name of the field, the field value must be a list of numbers.

Returns:

the function

sum

public static Function<Item,java.lang.Double> sum(java.lang.String numListField)

Calculate the sum of the numbers specified by a field. The list elements must be in Number type, such as Integer, Double, Long, ... If there is no valid field value in the stream, the "sum" result will be 0.0

Parameters:

numListField - the name of the field, the field value must be a list of numbers.

Returns:

the function

mean

public static Function<Item,java.lang.Double> mean(java.lang.String numListField)

Calculate the average of the numbers specified by a field. The list elements must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no number in the list), the result will be null.

Parameters:

numListField - the name of the field, the field value must be a list of numbers.

Returns:

the function

rms

public static Function<Item,java.lang.Double> rms(java.lang.String numListField)

Calculate the RMS (root mean square) of the numbers specified by a field. The list elements must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no number in the list), the result will be null.

Parameters:

numListField - the name of the field, the field value must be a list of numbers.

Returns:

the function

variance

public static Function<Item,java.lang.Double> variance(java.lang.String numListField)

Calculate the variance of the numbers specified by a field. The list elements must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no number in the list), the result will be null.

Parameters:

numListField - the name of the field, the field value must be a list of numbers.

Returns:

the function

max

public static Function<Item,java.lang.Number> max(java.lang.String numListField)

Get the max value of a field in the stream. The list elements must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no number in the list), the result will be null.

Parameters:

numListField - the name of the field, the field value must be a list of numbers.

Returns:

the function

min

public static Function<Item,java.lang.Number> min(java.lang.String numListField)

Get the min value of a field in the stream. The list elements must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no number in the list), the result will be null.

Parameters:

numListField - the name of the field, the field value must be a list of numbers.

Returns:

the function

median

public static Function<Item,java.lang.Number> median(java.lang.String numListField)

Get the median value of a field in the stream. The list elements must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no number in the list), the result will be null.

Parameters:

numListField - the name of the field, the field value must be a list of numbers.

Returns:

the function

mode

public static Function<Item,java.lang.Number> mode(java.lang.String numListField)

Get the mode value of a field in the stream. The list elements must be in Number type, such as Integer, Double, Long, ... If calculation fails (e.g. there is no number in the list), the result will be null.

Parameters:

numListField - the name of the field, the field value must be a list of numbers.

Returns:

the function