Evaluator (EngineBlock)

Type Parameters:

T - The return type that is needed by the caller

All Known Implementing Classes:

NashornEvaluator
```
public interface Evaluator<T>
```
An evaluator is a scripting helper that knows what its return type will be at runtime. You can create an Evaluator from an environment and a desired return type, then reuse it. Primitive types that can be mapped from the script to the return type should, including
- Double -> Long
- Double -> Integer
- Double -> Float
- Long -> Integer
An evaluator is not threadsafe by default. If you need threadsafe evaluators with similar semantics, wrap it in a ThreadLocal.

Method Summary

Modifier and Type	Method	Description
`T`	`eval()`	Evaluate the provided script, returning the value that it yields
`NashornEvaluator<T>`	`put(java.lang.String varName, java.lang.Object var)`	Set the variable environment of the evaluator
`NashornEvaluator<T>`	`script(java.lang.String scriptText)`

- Method Detail
  - eval
```
T eval()
```
    Evaluate the provided script, returning the value that it yields
    
    Returns:
    
    An object of type T
  - script
```
NashornEvaluator<T> script(java.lang.String scriptText)
```
    Parameters:
    
    scriptText - Nashorn compatible script text
    
    Returns:
    
    this NahornEvaluator, for method chaining
  - put
```
NashornEvaluator<T> put(java.lang.String varName,
                        java.lang.Object var)
```
    Set the variable environment of the evaluator
    
    Parameters:
    
    varName - the variable name to add to the environment
    
    var - the object to bind to the varname
    
    Returns:
    
    this NashornEvaluator, for method chaining