org.eclipse.equinox.p2.metadata.expression
Interface IExpressionFactory

All Known Subinterfaces:

IQLFactory

public interface IExpressionFactory

This interface provides all the factory methods needed to create the nodes of the expression tree.

Since:

2.0

Field Summary

static String	FUNC_BOOLEAN
static String	FUNC_CLASS
static String	FUNC_FILTER
static String	FUNC_RANGE
static String	FUNC_VERSION
static IExpression[]	NO_ARGS

Method Summary

IExpression	all(IExpression collection, IExpression lambda) Create a collection filter that yields true if the lambda yields true for all of the elements of the collection
IExpression	and(IExpression... operands) Create a logical and of its operands.
IExpression	array(IExpression... elements) Create an array of elements.
IExpression	at(IExpression target, IExpression key) Create an lookup of key in the target.
IExpression	constant(Object value) Creates an expression that evaluates to the constant value.
<T> IContextExpression<T>	contextExpression(IExpression expr, Object... parameters) Creates a top level expression that represents a full query.
IEvaluationContext	createContext(IExpression[] variables, Object... params) Create an evaluation context with one single variable
IEvaluationContext	createContext(Object... params) Create an evaluation context with one single variable
IExpression	equals(IExpression lhs, IExpression rhs) Create an expression that tests if lhs is equal to rhs.
IExpression	exists(IExpression collection, IExpression lambda) Create a collection filter that yields true if the lambda yields true for at least one of the elements of the collection
IFilterExpression	filterExpression(IExpression expression) Creates a top level expression suitable for predicate matching
IExpression	greater(IExpression lhs, IExpression rhs) Create an expression that tests if lhs is greater than rhs.
IExpression	greaterEqual(IExpression lhs, IExpression rhs) Create an expression that tests if lhs is greater than or equal to rhs.
IExpression	indexedParameter(int index) Creates an indexed parameter expression
IExpression	intersect(IExpression c1, IExpression c2) Create an intersection of c1 and c2
IExpression	lambda(IExpression variable, IExpression body) Creates a lambda expression that takes exactly one variable.
IExpression	latest(IExpression collection) Create an expression that yields a new collection consisting of the latest version of the elements of the collection.
IExpression	less(IExpression lhs, IExpression rhs) Create an expression that tests if lhs is less than rhs.
IExpression	lessEqual(IExpression lhs, IExpression rhs) Create an expression that tests if lhs is less than or equal to rhs.
IExpression	limit(IExpression collection, IExpression limit) Create an expression that yields a new collection consisting of the n first elements of the source collection where n is determined by limit.
IExpression	limit(IExpression collection, int count) Create an expression that yields a new collection consisting of the count first elements of the source collection.
IExpression	matches(IExpression lhs, IExpression rhs) Create an expression that tests if lhs matches rhs.
<T> IMatchExpression<T>	matchExpression(IExpression expression, Object... parameters) Creates a parameterized top level expression suitable for predicate matching
IExpression	member(IExpression target, String name) Creates a member accessor expression.
IExpression	normalize(List<? extends IExpression> operands, int expressionType) Performs boolean normalization on the expression to create a canonical form.
IExpression	not(IExpression operand) Creates an expression that negates the result of evaluating its operand.
IExpression	or(IExpression... operands) Create a logical or of its operands.
IExpression	pipe(IExpression... expressions) Create a pipe of expressions.
IExpression	select(IExpression collection, IExpression lambda) Create an expression that yields a new collection consisting of all elements of the collection for which the lambda yields true.
IExpression	thisVariable() Returns the variable that represents this in an expression
IExpression	toExpression(IQuery<?> query) Wrap an IQuery as an expression.
IExpression	union(IExpression c1, IExpression c2) Create a union of c1 and c2
IExpression	variable(String name) Creates an expression that represents a variable

Field Detail

FUNC_BOOLEAN

static final String FUNC_BOOLEAN

See Also:

Constant Field Values

FUNC_VERSION

static final String FUNC_VERSION

See Also:

Constant Field Values

FUNC_CLASS

static final String FUNC_CLASS

See Also:

Constant Field Values

FUNC_RANGE

static final String FUNC_RANGE

See Also:

Constant Field Values

FUNC_FILTER

static final String FUNC_FILTER

See Also:

Constant Field Values

NO_ARGS

static final IExpression[] NO_ARGS

Method Detail

all

IExpression all(IExpression collection,
                IExpression lambda)

Create a collection filter that yields true if the lambda yields true for all of the elements of the collection

Parameters:

collection - The collection providing the elements to test

lambda - The lambda that performs the test

Returns:

A boolean expression

and

IExpression and(IExpression... operands)

Create a logical and of its operands.

Parameters:

operands - The boolean operands

Returns:

A boolean expression

array

IExpression array(IExpression... elements)

Create an array of elements.

Parameters:

elements - The elements of the array

Returns:

An array expression

at

IExpression at(IExpression target,
               IExpression key)

Create an lookup of key in the target. The key expression should evaluate to a string or an integer.

Parameters:

target - The target for the lookup

key - The key to use for the lookup

Returns:

A lookup expression

createContext

IEvaluationContext createContext(Object... params)

Create an evaluation context with one single variable

Parameters:

params - Indexed parameters to use in the expression

Returns:

the context

createContext

IEvaluationContext createContext(IExpression[] variables,
                                 Object... params)

Create an evaluation context with one single variable

Parameters:

params - Indexed parameters to use in the expression

variables - The variables that will be maintained by the context

Returns:

the context

constant

IExpression constant(Object value)

Creates an expression that evaluates to the constant value.

Parameters:

value - The constant

Returns:

A constant expression

contextExpression

<T> IContextExpression<T> contextExpression(IExpression expr,
                                            Object... parameters)

Creates a top level expression that represents a full query.

Parameters:

expr - The query

parameters - The parameters of the query

Returns:

A top level query expression

equals

IExpression equals(IExpression lhs,
                   IExpression rhs)

Create an expression that tests if lhs is equal to rhs.

Parameters:

lhs - The left hand side value.

rhs - The right hand side value.

Returns:

A boolean expression

exists

IExpression exists(IExpression collection,
                   IExpression lambda)

Create a collection filter that yields true if the lambda yields true for at least one of the elements of the collection

Parameters:

collection - The collection providing the elements to test

lambda - The lambda that performs the test

Returns:

A boolean expression

filterExpression

IFilterExpression filterExpression(IExpression expression)

Creates a top level expression suitable for predicate matching

Parameters:

expression - The boolean expression

Returns:

A top level predicate expression

greater

IExpression greater(IExpression lhs,
                    IExpression rhs)

Create an expression that tests if lhs is greater than rhs.

Parameters:

lhs - The left hand side value.

rhs - The right hand side value.

Returns:

A boolean expression

greaterEqual

IExpression greaterEqual(IExpression lhs,
                         IExpression rhs)

Create an expression that tests if lhs is greater than or equal to rhs.

Parameters:

lhs - The left hand side value.

rhs - The right hand side value.

Returns:

A boolean expression

indexedParameter

IExpression indexedParameter(int index)

Creates an indexed parameter expression

Parameters:

index - The index to use

Returns:

a parameter expression

intersect

IExpression intersect(IExpression c1,
                      IExpression c2)

Create an intersection of c1 and c2

Parameters:

c1 - first collection

c2 - second collection

Returns:

An intersect expression

lambda

IExpression lambda(IExpression variable,
                   IExpression body)

Creates a lambda expression that takes exactly one variable. Suitable for use in most collection expressions.

Parameters:

variable - The element variable that the lambda uses

body - The body of the lambda

Returns:

A lambda expression

latest

IExpression latest(IExpression collection)

Create an expression that yields a new collection consisting of the latest version of the elements of the collection. Each element in collection must implement the IVersionedId interface.

Parameters:

collection - The collection providing the versioned elements

Returns:

A collection expression

less

IExpression less(IExpression lhs,
                 IExpression rhs)

Create an expression that tests if lhs is less than rhs.

Parameters:

lhs - The left hand side value.

rhs - The right hand side value.

Returns:

A boolean expression

lessEqual

IExpression lessEqual(IExpression lhs,
                      IExpression rhs)

Create an expression that tests if lhs is less than or equal to rhs.

Parameters:

lhs - The left hand side value.

rhs - The right hand side value.

Returns:

A boolean expression

limit

IExpression limit(IExpression collection,
                  int count)

Create an expression that yields a new collection consisting of the count first elements of the source collection.

Parameters:

collection - The source collection

count - The element count limit

Returns:

A collection expression

limit

IExpression limit(IExpression collection,
                  IExpression limit)

Create an expression that yields a new collection consisting of the n first elements of the source collection where n is determined by limit.

Parameters:

collection - The source collection

limit - The expression that evaluates to the element count limit

Returns:

A collection expression

normalize

IExpression normalize(List<? extends IExpression> operands,
                      int expressionType)

Performs boolean normalization on the expression to create a canonical form.

Parameters:

operands - The operands to normalize

expressionType - The type (must be either IExpression.TYPE_AND or IExpression.TYPE_OR.

Returns:

The normalized expression

matches

IExpression matches(IExpression lhs,
                    IExpression rhs)

Create an expression that tests if lhs matches rhs.

Parameters:

lhs - The left hand side value.

rhs - The right hand side value.

Returns:

A boolean expression

matchExpression

<T> IMatchExpression<T> matchExpression(IExpression expression,
                                        Object... parameters)

Creates a parameterized top level expression suitable for predicate matching

Parameters:

expression - The boolean expression

parameters - The parameters to use in the call

Returns:

A top level predicate expression

member

IExpression member(IExpression target,
                   String name)

Creates a member accessor expression.

Parameters:

target - The target for the member access

name - The name of the member

Returns:

A member expression

not

IExpression not(IExpression operand)

Creates an expression that negates the result of evaluating its operand.

Parameters:

operand - The boolean expression to negate

Returns:

A boolean expression

or

IExpression or(IExpression... operands)

Create a logical or of its operands.

Parameters:

operands - The boolean operands

Returns:

A boolean expression

pipe

IExpression pipe(IExpression... expressions)

Create a pipe of expressions.

Parameters:

expressions - The expressions that make out the pipe

Returns:

A pipe expression

select

IExpression select(IExpression collection,
                   IExpression lambda)

Create an expression that yields a new collection consisting of all elements of the collection for which the lambda yields true.

Parameters:

collection - The collection providing the elements to test

lambda - The lambda that performs the test

Returns:

A collection expression

thisVariable

IExpression thisVariable()

Returns the variable that represents this in an expression

Returns:

The this variable.

toExpression

IExpression toExpression(IQuery<?> query)

Wrap an IQuery as an expression.

Parameters:

query -

Returns:

An expression that wraps the query

union

IExpression union(IExpression c1,
                  IExpression c2)

Create a union of c1 and c2

Parameters:

c1 - first collection

c2 - second collection

Returns:

A union expression

variable

IExpression variable(String name)

Creates an expression that represents a variable

Parameters:

name - The name of the variable

Returns:

A variable expression