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

Interface IInfixExpressionHandler<TConstant extends IConstant,TOperator extends IOperator>

Type Parameters:

TConstant - Type of the implementation for constant symbols.

TOperator - Type of the implementation for operator symbols.

public interface IInfixExpressionHandler<TConstant extends IConstant,TOperator extends IOperator>

Handler that can tokenize, parse, and evaluate character sequences representing infix expressions.

Since:

7.0.0

Author:

XIMA MEDIA GmbH

Method Summary

Modifier and Type	Method	Description
<TData> TData	evaluate(IEvalContext<TData,TConstant,TOperator> ctx, Iterable<IParsedElement<TConstant,TOperator>> rpn, Locale locale)	Evaluates the given reverse polish notation with the given context.
Iterable<IParsedElement<TConstant,TOperator>>	parse(Iterable<IToken<TConstant,TOperator>> tokens, Locale locale)	Takes a token stream and parses it into a valid reverse polish notation representation.
Iterable<IToken<TConstant,TOperator>>	tokenize(CharSequence expression, Locale locale)	Inspects the given expressions and extracts the semantic tokens it consists of.
IValidationResult	validate(CharSequence expression, IValidationOptions options)	Validates the given infix expression.

Method Detail

evaluate

<TData> TData evaluate(IEvalContext<TData,TConstant,TOperator> ctx,
                       Iterable<IParsedElement<TConstant,TOperator>> rpn,
                       Locale locale)
                throws InfixExpressionException

Evaluates the given reverse polish notation with the given context.

Type Parameters:

TData - Type of the data on which the context operates.

Parameters:

ctx - Context for performing the evaluation.

rpn - Reverse polish expression to evaluate.

locale - Locale used for localizing error messages.

Returns:

The result of the evaluation. null when the expression contains no items, or the evaluation context returned null.

Throws:

InfixExpressionException - When the expression could not be evaluated, such as when the context threw an exception.

parse

Iterable<IParsedElement<TConstant,TOperator>> parse(Iterable<IToken<TConstant,TOperator>> tokens,
                                                          Locale locale)
                                                   throws InfixExpressionException

Takes a token stream and parses it into a valid reverse polish notation representation.

Parameters:

tokens - Tokens of an infix expression, such as created by tokenize(CharSequence, Locale). null is treated as the empty string.

locale - Locale used for localizing error messages.

Returns:

The given infix expression in reverse polish notation.

Throws:

InfixExpressionException - W@Override hen the input is not well-formed, such as when it contains missing parenthesis.

tokenize

Iterable<IToken<TConstant,TOperator>> tokenize(CharSequence expression,
                                                     Locale locale)
                                              throws InfixExpressionException

Inspects the given expressions and extracts the semantic tokens it consists of.

Parameters:

expression - An infix expression to tokenize.

locale - Locale used for localizing error messages.

Returns:

The list of tokens making up the given expression.

Throws:

InfixExpressionException - When the input expression cannot be split into tokens, such as when it contains an invalid identifier.

validate

IValidationResult validate(CharSequence expression,
                           IValidationOptions options)

Validates the given infix expression. Checks whether it is well-formed, and that each variable name passes the given existence check.

Parameters:

expression - Infix expression to validate.

options - Options to configure what is to be validated.

Returns:

The result of the validation.