ExpressionFactory

java.lang.Object
- org.eclipse.equinox.internal.p2.metadata.expression.ExpressionFactory

All Implemented Interfaces:: IExpressionConstants, IExpressionFactory

public class ExpressionFactory
extends java.lang.Object
implements IExpressionFactory, IExpressionConstants

Field Summary

Fields
Modifier and Type	Field and Description
`static Variable`	`EVERYTHING`
`protected static java.util.Map<java.lang.String,java.lang.reflect.Constructor<?>>`	`functionMap`
`static IExpressionFactory`	`INSTANCE`
`static Variable`	`THIS`

Fields inherited from interface org.eclipse.equinox.p2.metadata.expression.IExpressionFactory
FUNC_BOOLEAN, FUNC_CLASS, FUNC_FILTER, FUNC_RANGE, FUNC_VERSION, NO_ARGS

Fields inherited from interface org.eclipse.equinox.internal.p2.metadata.expression.IExpressionConstants
KEYWORD_ALL, KEYWORD_BOOLEAN, KEYWORD_CLASS, KEYWORD_COLLECT, KEYWORD_EXISTS, KEYWORD_FALSE, KEYWORD_FILTER, KEYWORD_FIRST, KEYWORD_FLATTEN, KEYWORD_INTERSECT, KEYWORD_IQUERY, KEYWORD_LATEST, KEYWORD_LIMIT, KEYWORD_LOCALIZED_KEYS, KEYWORD_LOCALIZED_MAP, KEYWORD_LOCALIZED_PROPERTY, KEYWORD_NULL, KEYWORD_RANGE, KEYWORD_SATISFIES_ALL, KEYWORD_SATISFIES_ANY, KEYWORD_SELECT, KEYWORD_SET, KEYWORD_TRAVERSE, KEYWORD_TRUE, KEYWORD_UNION, KEYWORD_UNIQUE, KEYWORD_VERSION, OPERATOR_AND, OPERATOR_ARRAY, OPERATOR_ASSIGN, OPERATOR_AT, OPERATOR_EACH, OPERATOR_ELSE, OPERATOR_EQUALS, OPERATOR_GT, OPERATOR_GT_EQUAL, OPERATOR_IF, OPERATOR_LT, OPERATOR_LT_EQUAL, OPERATOR_MATCHES, OPERATOR_MEMBER, OPERATOR_NOT, OPERATOR_NOT_EQUALS, OPERATOR_OR, OPERATOR_PARAMETER, PRIORITY_AND, PRIORITY_ASSIGNMENT, PRIORITY_BINARY, PRIORITY_COLLECTION, PRIORITY_COMMA, PRIORITY_CONDITION, PRIORITY_FUNCTION, PRIORITY_LAMBDA, PRIORITY_LITERAL, PRIORITY_MAX, PRIORITY_MEMBER, PRIORITY_NOT, PRIORITY_OR, PRIORITY_VARIABLE, VARIABLE_EVERYTHING, VARIABLE_THIS

Constructor Summary

Constructors
Constructor and Description

ExpressionFactory()

Constructors
Constructor and Description
`ExpressionFactory()`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`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... operands)` Create an array of elements.
`IExpression`	`assignment(IExpression variable, IExpression expression)` Creates an expression that represents a variable assignment
`IExpression`	`at(IExpression target, IExpression key)` Create an lookup of `key` in the `target`.
`IExpression`	`collect(IExpression collection, IExpression lambda)` Create an expression that collects the result of evaluating each element in a new collection.
`IExpression`	`condition(IExpression test, IExpression ifTrue, IExpression ifFalse)` Create an expression that first evaluates a `test` and then, depending on the outcome, evaluates either `ifTrue` or `ifFalse`.
`IExpression`	`constant(java.lang.Object value)` Creates an expression that evaluates to the constant `value`.
`<T> IContextExpression<T>`	`contextExpression(IExpression expression, java.lang.Object... parameters)` Creates a top level expression that represents a full query.
`protected static Expression[]`	`convertArray(IExpression[] operands)`
`IEvaluationContext`	`createContext(IExpression[] variables, java.lang.Object... parameters)` Create an evaluation context with one single variable
`IEvaluationContext`	`createContext(java.lang.Object... parameters)` 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`	`first(IExpression collection, IExpression lambda)` Create an expression that yields the first element of the `collection` for which the `lambda` yields `true`.
`IExpression`	`flatten(IExpression collection)` Intended to be applied on collections of collections.
`IExpression`	`function(java.lang.Object function, IExpression... args)` Given one of the values in the map returned by `IExpressionFactory.getFunctionMap()`, this method returns a function expression.
`java.util.Map<java.lang.String,? extends java.lang.Object>`	`getFunctionMap()` Returns a map of functions supported by this factory.
`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`	`lambda(IExpression variable, IExpression[] assignments, IExpression body)` Creates a lambda expression that takes more then one variable (currying).
`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, java.lang.Object... parameters)` Creates a parameterized top level expression suitable for predicate matching
`IExpression`	`member(IExpression target, java.lang.String name)` Creates a member accessor expression.
`IExpression`	`memberCall(IExpression target, java.lang.String name, IExpression... args)` Creates a member call expression.
`IExpression`	`normalize(java.util.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... operands)` 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`	`traverse(IExpression collection, IExpression lambda)` Recursively traverse and collect elements based on a condition A common scenario in p2 is that you want to start with a set of roots and then find all items that fulfill the root requirements.
`IExpression`	`union(IExpression c1, IExpression c2)` Create a union of `c1` and `c2`
`IExpression`	`unique(IExpression collection, IExpression cache)` Create an expression that yields a new collection where each element is unique.
`IExpression`	`variable(java.lang.String name)` Creates an expression that represents a variable

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - EVERYTHING
```
public static final Variable EVERYTHING
```
  - functionMap
```
protected static final java.util.Map<java.lang.String,java.lang.reflect.Constructor<?>> functionMap
```
  - INSTANCE
```
public static final IExpressionFactory INSTANCE
```
  - THIS
```
public static final Variable THIS
```
- Constructor Detail
  - ExpressionFactory
```
public ExpressionFactory()
```
- Method Detail
  - convertArray
```
protected static Expression[] convertArray(IExpression[] operands)
```
  - all
```
public IExpression all(IExpression collection,
                       IExpression lambda)
```
    Description copied from interface: IExpressionFactory
    
    Create a collection filter that yields true if the lambda yields true for all of the elements of the collection
    
    Specified by:
    
    all in interface IExpressionFactory
    
    Parameters:
    
    collection - The collection providing the elements to test
    
    lambda - The lambda that performs the test
    
    Returns:
    
    A boolean expression
  - and
```
public IExpression and(IExpression... operands)
```
    Description copied from interface: IExpressionFactory
    
    Create a logical and of its operands.
    
    Specified by:
    
    and in interface IExpressionFactory
    
    Parameters:
    
    operands - The boolean operands
    
    Returns:
    
    A boolean expression
  - array
```
public IExpression array(IExpression... operands)
```
    Description copied from interface: IExpressionFactory
    
    Create an array of elements.
    
    Specified by:
    
    array in interface IExpressionFactory
    
    Parameters:
    
    operands - The elements of the array
    
    Returns:
    
    An array expression
  - assignment
```
public IExpression assignment(IExpression variable,
                              IExpression expression)
```
    Description copied from interface: IExpressionFactory
    
    Creates an expression that represents a variable assignment
    
    Specified by:
    
    assignment in interface IExpressionFactory
    
    Parameters:
    
    variable - The variable
    
    expression - The expression that yields the value to assign to the variable
    
    Returns:
    
    An assignment expression
  - at
```
public IExpression at(IExpression target,
                      IExpression key)
```
    Description copied from interface: IExpressionFactory
    
    Create an lookup of key in the target. The key expression should evaluate to a string or an integer.
    
    Specified by:
    
    at in interface IExpressionFactory
    
    Parameters:
    
    target - The target for the lookup
    
    key - The key to use for the lookup
    
    Returns:
    
    A lookup expression
  - collect
```
public IExpression collect(IExpression collection,
                           IExpression lambda)
```
    Description copied from interface: IExpressionFactory
    
    Create an expression that collects the result of evaluating each element in a new collection.
    
    Specified by:
    
    collect in interface IExpressionFactory
    
    Parameters:
    
    collection - The collection providing the elements to evaluate
    
    lambda - The lambda that creates each new element
    
    Returns:
    
    A collection expression
  - condition
```
public IExpression condition(IExpression test,
                             IExpression ifTrue,
                             IExpression ifFalse)
```
    Description copied from interface: IExpressionFactory
    
    Create an expression that first evaluates a test and then, depending on the outcome, evaluates either ifTrue or ifFalse. The expression yields the result of the ifTrue or ifFalse evaluation.
    
    Specified by:
    
    condition in interface IExpressionFactory
    
    Parameters:
    
    test - The test
    
    ifTrue - The code to evaluate when the test evaluates to true
    
    ifFalse - The code to evaluate when the test evaluates to false
    
    Returns:
    
    The conditional expression
  - constant
```
public IExpression constant(java.lang.Object value)
```
    Description copied from interface: IExpressionFactory
    
    Creates an expression that evaluates to the constant value.
    
    Specified by:
    
    constant in interface IExpressionFactory
    
    Parameters:
    
    value - The constant
    
    Returns:
    
    A constant expression
  - contextExpression
```
public <T> IContextExpression<T> contextExpression(IExpression expression,
                                                   java.lang.Object... parameters)
```
    Description copied from interface: IExpressionFactory
    
    Creates a top level expression that represents a full query.
    
    Specified by:
    
    contextExpression in interface IExpressionFactory
    
    Parameters:
    
    expression - The query
    
    parameters - The parameters of the query
    
    Returns:
    
    A top level query expression
  - createContext
```
public IEvaluationContext createContext(IExpression[] variables,
                                        java.lang.Object... parameters)
```
    Description copied from interface: IExpressionFactory
    
    Create an evaluation context with one single variable
    
    Specified by:
    
    createContext in interface IExpressionFactory
    
    Parameters:
    
    variables - The variables that will be maintained by the context
    
    parameters - Indexed parameters to use in the expression
    
    Returns:
    
    the context
  - createContext
```
public IEvaluationContext createContext(java.lang.Object... parameters)
```
    Description copied from interface: IExpressionFactory
    
    Create an evaluation context with one single variable
    
    Specified by:
    
    createContext in interface IExpressionFactory
    
    Parameters:
    
    parameters - Indexed parameters to use in the expression
    
    Returns:
    
    the context
  - equals
```
public IExpression equals(IExpression lhs,
                          IExpression rhs)
```
    Description copied from interface: IExpressionFactory
    
    Create an expression that tests if lhs is equal to rhs.
    
    Specified by:
    
    equals in interface IExpressionFactory
    
    Parameters:
    
    lhs - The left hand side value.
    
    rhs - The right hand side value.
    
    Returns:
    
    A boolean expression
  - exists
```
public IExpression exists(IExpression collection,
                          IExpression lambda)
```
    Description copied from interface: IExpressionFactory
    
    Create a collection filter that yields true if the lambda yields true for at least one of the elements of the collection
    
    Specified by:
    
    exists in interface IExpressionFactory
    
    Parameters:
    
    collection - The collection providing the elements to test
    
    lambda - The lambda that performs the test
    
    Returns:
    
    A boolean expression
  - filterExpression
```
public IFilterExpression filterExpression(IExpression expression)
```
    Description copied from interface: IExpressionFactory
    
    Creates a top level expression suitable for predicate matching
    
    Specified by:
    
    filterExpression in interface IExpressionFactory
    
    Parameters:
    
    expression - The boolean expression
    
    Returns:
    
    A top level predicate expression
  - first
```
public IExpression first(IExpression collection,
                         IExpression lambda)
```
    Description copied from interface: IExpressionFactory
    
    Create an expression that yields the first element of the collection for which the lambda yields true.
    
    Specified by:
    
    first in interface IExpressionFactory
    
    Parameters:
    
    collection - The collection providing the elements to test
    
    lambda - The lambda that performs the test
    
    Returns:
    
    An element expression
  - flatten
```
public IExpression flatten(IExpression collection)
```
    Description copied from interface: IExpressionFactory
    
    Intended to be applied on collections of collections. Yields a single collection with all elements from the source collections, in the order they are evaluated.
    
    Specified by:
    
    flatten in interface IExpressionFactory
    
    Parameters:
    
    collection - The collection providing the collections that provides all elements
    
    Returns:
    
    A collection expression
  - function
```
public IExpression function(java.lang.Object function,
                            IExpression... args)
```
    Description copied from interface: IExpressionFactory
    
    Given one of the values in the map returned by IExpressionFactory.getFunctionMap(), this method returns a function expression.
    
    Specified by:
    
    function in interface IExpressionFactory
    
    Parameters:
    
    function - The value obtained from the map.
    
    args - The arguments to evaluate and pass when evaluating the function.
    
    Returns:
    
    A function expression
  - getFunctionMap
```
public java.util.Map<java.lang.String,? extends java.lang.Object> getFunctionMap()
```
    Description copied from interface: IExpressionFactory
    
    Returns a map of functions supported by this factory. The map is keyed by function names and the value is an object suitable to pass to the IExpressionFactory.function(Object, IExpression[]) method.
    
    Specified by:
    
    getFunctionMap in interface IExpressionFactory
    
    Returns:
    
    A key/function map.
  - greater
```
public IExpression greater(IExpression lhs,
                           IExpression rhs)
```
    Description copied from interface: IExpressionFactory
    
    Create an expression that tests if lhs is greater than rhs.
    
    Specified by:
    
    greater in interface IExpressionFactory
    
    Parameters:
    
    lhs - The left hand side value.
    
    rhs - The right hand side value.
    
    Returns:
    
    A boolean expression
  - greaterEqual
```
public IExpression greaterEqual(IExpression lhs,
                                IExpression rhs)
```
    Description copied from interface: IExpressionFactory
    
    Create an expression that tests if lhs is greater than or equal to rhs.
    
    Specified by:
    
    greaterEqual in interface IExpressionFactory
    
    Parameters:
    
    lhs - The left hand side value.
    
    rhs - The right hand side value.
    
    Returns:
    
    A boolean expression
  - indexedParameter
```
public IExpression indexedParameter(int index)
```
    Description copied from interface: IExpressionFactory
    
    Creates an indexed parameter expression
    
    Specified by:
    
    indexedParameter in interface IExpressionFactory
    
    Parameters:
    
    index - The index to use
    
    Returns:
    
    a parameter expression
  - intersect
```
public IExpression intersect(IExpression c1,
                             IExpression c2)
```
    Description copied from interface: IExpressionFactory
    
    Create an intersection of c1 and c2
    
    Specified by:
    
    intersect in interface IExpressionFactory
    
    Parameters:
    
    c1 - first collection
    
    c2 - second collection
    
    Returns:
    
    An intersect expression
  - lambda
```
public IExpression lambda(IExpression variable,
                          IExpression body)
```
    Description copied from interface: IExpressionFactory
    
    Creates a lambda expression that takes exactly one variable. Suitable for use in most collection expressions.
    
    Specified by:
    
    lambda in interface IExpressionFactory
    
    Parameters:
    
    variable - The element variable that the lambda uses
    
    body - The body of the lambda
    
    Returns:
    
    A lambda expression
  - lambda
```
public IExpression lambda(IExpression variable,
                          IExpression[] assignments,
                          IExpression body)
```
    Description copied from interface: IExpressionFactory
    
    Creates a lambda expression that takes more then one variable (currying). Suitable for use in most collection expressions.
    
    Specified by:
    
    lambda in interface IExpressionFactory
    
    Parameters:
    
    variable - The element variable that the lambda uses
    
    assignments - Assignments to evaluate once before calling the body for each element.
    
    body - The body of the lambda
    
    Returns:
    
    A lambda expression with currying
  - latest
```
public IExpression latest(IExpression collection)
```
    Description copied from interface: IExpressionFactory
    
    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.
    
    Specified by:
    
    latest in interface IExpressionFactory
    
    Parameters:
    
    collection - The collection providing the versioned elements
    
    Returns:
    
    A collection expression
  - less
```
public IExpression less(IExpression lhs,
                        IExpression rhs)
```
    Description copied from interface: IExpressionFactory
    
    Create an expression that tests if lhs is less than rhs.
    
    Specified by:
    
    less in interface IExpressionFactory
    
    Parameters:
    
    lhs - The left hand side value.
    
    rhs - The right hand side value.
    
    Returns:
    
    A boolean expression
  - lessEqual
```
public IExpression lessEqual(IExpression lhs,
                             IExpression rhs)
```
    Description copied from interface: IExpressionFactory
    
    Create an expression that tests if lhs is less than or equal to rhs.
    
    Specified by:
    
    lessEqual in interface IExpressionFactory
    
    Parameters:
    
    lhs - The left hand side value.
    
    rhs - The right hand side value.
    
    Returns:
    
    A boolean expression
  - limit
```
public IExpression limit(IExpression collection,
                         IExpression limit)
```
    Description copied from interface: IExpressionFactory
    
    Create an expression that yields a new collection consisting of the n first elements of the source collection where n is determined by limit.
    
    Specified by:
    
    limit in interface IExpressionFactory
    
    Parameters:
    
    collection - The source collection
    
    limit - The expression that evaluates to the element count limit
    
    Returns:
    
    A collection expression
  - limit
```
public IExpression limit(IExpression collection,
                         int count)
```
    Description copied from interface: IExpressionFactory
    
    Create an expression that yields a new collection consisting of the count first elements of the source collection.
    
    Specified by:
    
    limit in interface IExpressionFactory
    
    Parameters:
    
    collection - The source collection
    
    count - The element count limit
    
    Returns:
    
    A collection expression
  - matches
```
public IExpression matches(IExpression lhs,
                           IExpression rhs)
```
    Description copied from interface: IExpressionFactory
    
    Create an expression that tests if lhs matches rhs.
    
    Specified by:
    
    matches in interface IExpressionFactory
    
    Parameters:
    
    lhs - The left hand side value.
    
    rhs - The right hand side value.
    
    Returns:
    
    A boolean expression
  - matchExpression
```
public <T> IMatchExpression<T> matchExpression(IExpression expression,
                                               java.lang.Object... parameters)
```
    Description copied from interface: IExpressionFactory
    
    Creates a parameterized top level expression suitable for predicate matching
    
    Specified by:
    
    matchExpression in interface IExpressionFactory
    
    Parameters:
    
    expression - The boolean expression
    
    parameters - The parameters to use in the call
    
    Returns:
    
    A top level predicate expression
  - member
```
public IExpression member(IExpression target,
                          java.lang.String name)
```
    Description copied from interface: IExpressionFactory
    
    Creates a member accessor expression.
    
    Specified by:
    
    member in interface IExpressionFactory
    
    Parameters:
    
    target - The target for the member access
    
    name - The name of the member
    
    Returns:
    
    A member expression
  - memberCall
```
public IExpression memberCall(IExpression target,
                              java.lang.String name,
                              IExpression... args)
```
    Description copied from interface: IExpressionFactory
    
    Creates a member call expression.
    
    Specified by:
    
    memberCall in interface IExpressionFactory
    
    Parameters:
    
    target - The target for the member call
    
    name - The name of the member
    
    args - The arguments to use for the call
    
    Returns:
    
    A member expression
  - normalize
```
public IExpression normalize(java.util.List<? extends IExpression> operands,
                             int expressionType)
```
    Description copied from interface: IExpressionFactory
    
    Performs boolean normalization on the expression to create a canonical form.
    
    Specified by:
    
    normalize in interface IExpressionFactory
    
    Parameters:
    
    operands - The operands to normalize
    
    expressionType - The type (must be either IExpression.TYPE_AND or IExpression.TYPE_OR.
    
    Returns:
    
    The normalized expression
  - not
```
public IExpression not(IExpression operand)
```
    Description copied from interface: IExpressionFactory
    
    Creates an expression that negates the result of evaluating its operand.
    
    Specified by:
    
    not in interface IExpressionFactory
    
    Parameters:
    
    operand - The boolean expression to negate
    
    Returns:
    
    A boolean expression
  - or
```
public IExpression or(IExpression... operands)
```
    Description copied from interface: IExpressionFactory
    
    Create a logical or of its operands.
    
    Specified by:
    
    or in interface IExpressionFactory
    
    Parameters:
    
    operands - The boolean operands
    
    Returns:
    
    A boolean expression
  - pipe
```
public IExpression pipe(IExpression... operands)
```
    Description copied from interface: IExpressionFactory
    
    Create a pipe of expressions.
    
    Specified by:
    
    pipe in interface IExpressionFactory
    
    Parameters:
    
    operands - The expressions that make out the pipe
    
    Returns:
    
    A pipe expression
  - select
```
public IExpression select(IExpression collection,
                          IExpression lambda)
```
    Description copied from interface: IExpressionFactory
    
    Create an expression that yields a new collection consisting of all elements of the collection for which the lambda yields true.
    
    Specified by:
    
    select in interface IExpressionFactory
    
    Parameters:
    
    collection - The collection providing the elements to test
    
    lambda - The lambda that performs the test
    
    Returns:
    
    A collection expression
  - thisVariable
```
public IExpression thisVariable()
```
    Description copied from interface: IExpressionFactory
    
    Returns the variable that represents this in an expression
    Specified by: thisVariable in interface IExpressionFactory Returns: The this variable.
  toExpression public IExpression toExpression(IQuery<?> query) Description copied from interface: IExpressionFactory Wrap an IQuery as an expression. Specified by: toExpression in interface IExpressionFactory Returns: An expression that wraps the query traverse public IExpression traverse(IExpression collection, IExpression lambda) Description copied from interface: IExpressionFactory Recursively traverse and collect elements based on a condition A common scenario in p2 is that you want to start with a set of roots and then find all items that fulfill the root requirements. Those items in turn introduce new requirements so you want to find them too. The process continues until no more requirements can be satisfied. This type of query can be performed using the traverse function. The function will evaluate an expression, once for each element, collect elements for which the evaluation returned true, then then re-evaluate using the collected result as source of elements. No element is evaluated twice. This continues until no more elements are found. Specified by: traverse in interface IExpressionFactory Parameters: collection - The collection providing the elements to test lambda - The lambda that collects the children for the next iteration Returns: A collection expression union public IExpression union(IExpression c1, IExpression c2) Description copied from interface: IExpressionFactory Create a union of c1 and c2 Specified by: union in interface IExpressionFactory Parameters: c1 - first collection c2 - second collection Returns: A union expression unique public IExpression unique(IExpression collection, IExpression cache) Description copied from interface: IExpressionFactory Create an expression that yields a new collection where each element is unique. An optional cache can be provided if the uniqueness should span a larger scope then just the source collection. Specified by: unique in interface IExpressionFactory Parameters: collection - The source collection cache - Optional cache to use when uniqueness should span over several invocations Returns: A collection expression variable public IExpression variable(java.lang.String name) Description copied from interface: IExpressionFactory Creates an expression that represents a variable Specified by: variable in interface IExpressionFactory Parameters: name - The name of the variable Returns: A variable expression

Class ExpressionFactory

Field Summary

Fields inherited from interface org.eclipse.equinox.p2.metadata.expression.IExpressionFactory

Fields inherited from interface org.eclipse.equinox.internal.p2.metadata.expression.IExpressionConstants

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

EVERYTHING

functionMap

INSTANCE

THIS

Constructor Detail

ExpressionFactory

Method Detail

convertArray

all

and

array

assignment

at

collect

condition

constant

contextExpression

createContext

createContext

equals

exists

filterExpression

first

flatten

function

getFunctionMap

greater

greaterEqual

indexedParameter

intersect

lambda

lambda

latest

less

lessEqual

limit

limit

matches

matchExpression

member

memberCall

normalize

not

or

pipe

select

thisVariable

toExpression

traverse

union

unique

variable