Expression (Atlas :: Expression 2.4.0-M.4 API)

All Known Subinterfaces:

BooleanExpression

All Known Implementing Classes:

ArithmeticExpression, BinaryExpression, ComparisonExpression, ConstantExpression, LogicExpression, UnaryExpression, VariableExpression
```
public interface Expression
```
Parses and evaluates a simple expression language. This was originally based on the selector expression language found in ActiveMQ. It was modified so that it's supports custom functions and it's comparison expressions were less SQL like, and more script like.

Field Summary

Fields
Modifier and Type Field Description

static LRUCache<String,Object> CACHE
cache.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`static void`	`clearCache()`	Clears the cache.
`io.atlasmap.v2.Field`	`evaluate(ExpressionContext expressionContext)`	Execute the expression against the given context.
`static Expression`	`parse(String expessionText, FunctionResolver functionResolver)`	Parses the expression text.

- Field Detail
  - CACHE
```
static final LRUCache<String,Object> CACHE
```
    cache.
- Method Detail
  - evaluate
```
io.atlasmap.v2.Field evaluate(ExpressionContext expressionContext)
                       throws ExpressionException
```
    Execute the expression against the given context.
    
    Parameters:
    
    expressionContext - ExpressionContext
    
    Returns:
    
    Field represents a result
    
    Throws:
    
    ExpressionException - If evaluation fails
  - parse
```
static Expression parse(String expessionText,
                        FunctionResolver functionResolver)
                 throws ExpressionException
```
    Parses the expression text.
    
    Parameters:
    
    expessionText - expression text
    
    functionResolver - function resolver
    
    Returns:
    
    result
    
    Throws:
    
    ExpressionException - unexpected error
  - clearCache
```
static void clearCache()
```
    Clears the cache.