Package org.apache.sis.filter

Class ArithmeticFunction<R>

java.lang.Object

org.apache.sis.internal.filter.Node

org.apache.sis.filter.BinaryFunction<R,Number,Number>

org.apache.sis.filter.ArithmeticFunction<R>

Type Parameters:

R - the type of resources (e.g. Feature) used as inputs.

All Implemented Interfaces:

Serializable, Function<R,Number>, Expression<R,Number>, Optimization.OnExpression<R,Number>, FeatureExpression<R,Number>

Direct Known Subclasses:

ArithmeticFunction.Add, ArithmeticFunction.Divide, ArithmeticFunction.Multiply, ArithmeticFunction.Subtract

abstract class ArithmeticFunction<R>
extends BinaryFunction<R,Number,Number>
implements FeatureExpression<R,Number>, Optimization.OnExpression<R,Number>

Arithmetic operations between two numerical values. The nature of the operation depends on the subclass.

Since:

1.1

Version:

1.1

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static final class	ArithmeticFunction.Add<R>	The "Add" (+) expression.
(package private) static final class	ArithmeticFunction.Divide<R>	The "Divide" (÷) expression.
(package private) static final class	ArithmeticFunction.Multiply<R>	The "Multiply" (×) expression.
(package private) static final class	ArithmeticFunction.Subtract<R>	The "Subtract" (−) expression.

Field Summary

Fields

Modifier and Type	Field	Description
private static final long	serialVersionUID	For cross-version compatibility.

Fields inherited from class org.apache.sis.filter.BinaryFunction

expression1, expression2

Constructor Summary

Constructors

Constructor	Description
ArithmeticFunction(Expression<? super R,? extends Number> expression1, Expression<? super R,? extends Number> expression2)	Creates a new arithmetic function.

Method Summary

Modifier and Type	Method	Description
final Number	apply(R feature)	Evaluates the expression for producing a result of numeric type.
(package private) static DefaultAttributeType<Number>	createNumericType(String name)	Creates an attribute type for numeric values of the given name.
protected abstract DefaultAttributeType<Number>	expectedType()	Returns the type of results computed by this arithmetic function.
final PropertyTypeBuilder	expectedType(DefaultFeatureType ignored, FeatureTypeBuilder addTo)	Provides the type of results computed by this expression.
final Class<?>	getValueClass()	Returns the type of values computed by this expression.
<N> Expression<R,N>	toValueType(Class<N> target)	Returns this if this expression provides values of the specified type, or otherwise returns an expression doing conversions on-the-fly.

Methods inherited from class org.apache.sis.filter.BinaryFunction

apply, applyAsDecimal, applyAsDouble, applyAsFraction, applyAsInteger, applyAsLong, getChildren, getExpressions, getParameters

Methods inherited from class org.apache.sis.internal.filter.Node

createName, createType, equals, getGeometryLibrary, hashCode, symbol, toGeometryWrapper, toString, unwrap, warning

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.sis.filter.Expression

getFunctionName, getParameters

Methods inherited from interface java.util.function.Function

andThen, compose

Methods inherited from interface org.apache.sis.filter.Optimization.OnExpression

optimize, recreate

Field Details

serialVersionUID

private static final long serialVersionUID

For cross-version compatibility.

See Also:

• Constant Field Values

Constructor Details

ArithmeticFunction

ArithmeticFunction(Expression<? super R,? extends Number> expression1,
 Expression<? super R,? extends Number> expression2)

Creates a new arithmetic function.

Method Details

createNumericType

static DefaultAttributeType<Number> createNumericType(String name)

Creates an attribute type for numeric values of the given name. The attribute is mandatory, unbounded and has no default value.

Parameters:

name - name of the attribute to create.

Returns:

an attribute of the given name for numbers.

expectedType

protected abstract DefaultAttributeType<Number> expectedType()

Returns the type of results computed by this arithmetic function.

getValueClass

public final Class<?> getValueClass()

Returns the type of values computed by this expression.

Specified by:

getValueClass in interface FeatureExpression<R,Number>

Returns:

the type of values computed by this expression.

expectedType

public final PropertyTypeBuilder expectedType(DefaultFeatureType ignored,
 FeatureTypeBuilder addTo)

Provides the type of results computed by this expression. That type depends only on the ArithmeticFunction subclass and is given by expectedType().

Specified by:

expectedType in interface FeatureExpression<R,Number>

Parameters:

ignored - the type of features to be evaluated by the given expression.

addTo - where to add the type of properties evaluated by this expression.

Returns:

builder of the added property, or null if this method cannot add a property.

apply

public final Number apply(R feature)

Evaluates the expression for producing a result of numeric type. This method delegates to one of the applyAs(…) methods. If no applyAs(…) implementations can return null values, this this method never return null.

Specified by:

apply in interface Expression<R,Number>

Specified by:

apply in interface Function<R,Number>

Parameters:

feature - the object to be evaluated by the expression. Can be null if this expression allows null values.

Returns:

value computed by the expression.

toValueType

public <N> Expression<R,N> toValueType(Class<N> target)

Returns this if this expression provides values of the specified type, or otherwise returns an expression doing conversions on-the-fly.

Specified by:

toValueType in interface Expression<R,Number>

Type Parameters:

N - compile-time value of type.

Parameters:

target - desired type of expression results.

Returns:

expression doing the same operation this this expression but with results of the specified type.

Throws:

ClassCastException - if the specified type is not a supported target type.