Package de.xima.fc.workflow.parser.infix.bool

Class BooleanExpression

java.lang.Object

de.xima.fc.workflow.parser.infix.bool.BooleanExpression

public final class BooleanExpression
extends Object

Utility methods specific to infix expressions consisting of boolean constant, operators, and variables. See also InfixExpression. A boolean infix expression looks like this:

 (a or b) and c or true
 

The supported operators are defined by EBooleanOperator, the defined constants by EBooleanConstant.

Since:

7.0.0

Author:

XIMA MEDIA GmbH

Method Summary

Modifier and Type	Method	Description
static Boolean	eval(CharSequence expression, Function<String,Boolean> variableResolver, Locale locale)	Utility method that retrieves the parser, parses the infix expression, and evaluates it.
static Iterable<IConstant>	getConstants()
static IInfixExpressionHandler<de.xima.fc.workflow.parser.infix.bool.EBooleanConstant,de.xima.fc.workflow.parser.infix.bool.EBooleanOperator>	getHandler()
static Iterable<IOperator>	getOperators()
static IEvalContext<Boolean,de.xima.fc.workflow.parser.infix.bool.EBooleanConstant,de.xima.fc.workflow.parser.infix.bool.EBooleanOperator>	newEvalContext(Function<String,Boolean> variableResolver)	Creates a new context for evaluating boolean expressions.

Methods inherited from class java.lang.Object

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

Method Detail

eval

public static Boolean eval(CharSequence expression,
                           Function<String,Boolean> variableResolver,
                           Locale locale)
                    throws InfixExpressionException

Utility method that retrieves the parser, parses the infix expression, and evaluates it.

Parameters:

expression - Expression to parse.

variableResolver - Resolver that returns the value for a given variable name. May return null when no value is available -- this is treated as false. If you have a Map<String, Boolean>, you can just use a map::get method reference.

locale - Locale for localizing error messages.

Returns:

The result obtained by evaluating the expression with the given variable resolver.

Throws:

InfixExpressionException - When the expression could not be parsed or evaluated, such as when its syntax is wrong or the variable resolver threw an exception.

getHandler

public static IInfixExpressionHandler<de.xima.fc.workflow.parser.infix.bool.EBooleanConstant,de.xima.fc.workflow.parser.infix.bool.EBooleanOperator> getHandler()

Returns:

The immutable instance of the parser for boolean infix expressions.

newEvalContext

public static IEvalContext<Boolean,de.xima.fc.workflow.parser.infix.bool.EBooleanConstant,de.xima.fc.workflow.parser.infix.bool.EBooleanOperator> newEvalContext(Function<String,Boolean> variableResolver)

Creates a new context for evaluating boolean expressions.

Parameters:

variableResolver - Resolver that returns the value for a given variable name. May return null when no value is available -- this is treated as false.

Returns:

A new evaluation context with the given variable resolver.

getOperators

public static Iterable<IOperator> getOperators()

Returns:

A list of all operators supported by this type of expression.

getConstants

public static Iterable<IConstant> getConstants()

Returns:

A list of all constants supported by this type of expression.