@XmlSchema(URL="http://schemas.opengis.net/filter/1.0.0/filter.xsd", specification=OGC_02059)

Package org.opengis.filter.expression

An expression is a combination of one or more elements that evaluate to single Object value.

See: Description

Interface Summary

Interface	Description
Add	Encodes the operation of addition.
BinaryExpression	Abstract base class for the various filter expressions that compute some value from two input values.
Divide	Encodes the operation of division where the first argument is divided by the second argument.
Expression	Abstract super-interface for all the OGC Filter elements that compute values, potentially using feature attributes in the computation.
ExpressionVisitor	Visitor with visit methods to be called by Expression.accept(...).
Function	Instances of this class represent a function call into some implementation-specific function.
Literal	Instances of this interface provide a constant, literal value that can be used in expressions.
Multiply	Encodes the operation of multiplication.
PropertyName	Expression class whose value is computed by retrieving the value of a feature's property.
Subtract	Encodes the operation of subtraction where the second argument is subtracted from the first.

Package org.opengis.filter.expression Description

An expression is a combination of one or more elements that evaluate to single Object value. The following is adapted from Filter encoding implementation:

An expression can be formed using the elements: Add, Subtract, Multiply, Divide, PropertyName, Literal and Function. They all belong to the substitution group expression which means that any of them can be used wherever an expression is called for. In addition, the combinaison of these elements are themselves expressions and can be used wherever an expression is called for.

Arithmetic operators

The elements defined in this package are used to encode the fundamental arithmetic operations of addition, subtraction, multiplication and division. Arithmetic operators are binary operators meaning that they accept two arguments and evaluate to a single result.

Literals

A literal value is any part of a statement or expression that is to be used exactly as it is specified, rather than as a variable or other element. The Literal element is used to encode literal scalar and geometric values.

Functions

A function is a named procedure that performs a distinct computation. A function may accept zero or more arguments as input and generates a single result. A function is composed of the name of the function, encoded using the attribute name, and zero or more arguments contained within the Function element. The arguments themselves are expressions.