DebugValue

java.lang.Object
- com.oracle.truffle.api.debug.DebugValue

```
public abstract class DebugValue
extends Object
```
Represents a value accessed using the debugger API. Please note that values can become invalid depending on the context in which they are used. For example stack values will only remain valid as long as the current stack element is active. Heap values on the other hand remain valid. If a value becomes invalid then setting or getting a value will throw an IllegalStateException . DebugValue instances neither support equality or preserve identity.
Clients may access the debug value only on the execution thread where the suspended event of the stack frame was created and notification received; access from other threads will throw IllegalStateException.

Since:

0.17

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`abstract <T> T`	`as(Class<T> clazz)` Converts the debug value into a Java type.
`List<DebugValue>`	`getArray()` Provides array elements when this value represents an array.
`DebugValue`	`getMetaObject()` Get a meta-object of this value, if any.
`abstract String`	`getName()` Returns the name of this value as it is referred to from its origin.
`Collection<DebugValue>`	`getProperties()` Provides properties representing an internal structure of this value.
`DebugScope`	`getScope()` Get the scope where this value is declared in.
`SourceSection`	`getSourceLocation()` Get a source location where this value is declared, if any.
`boolean`	`isArray()` Returns `true` if this value represents an array, `false` otherwise.
`abstract boolean`	`isInternal()` Returns `true` if this value represents an internal implementation detail, `false` otherwise.
`abstract boolean`	`isReadable()` Returns `true` if this value can be read else `false`.
`abstract boolean`	`isWritable()` Returns `true` if this value can be written to, else `false`.
`abstract void`	`set(DebugValue value)` Sets the value using another `DebugValue`.
`String`	`toString()` Returns a string representation of the debug value.

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

- Method Detail
  - set
```
public abstract void set(DebugValue value)
```
    Sets the value using another DebugValue. Throws an IllegalStateException if the value is not writable, the passed value is not readable, this value or the passed value is invalid, or the guest language of the values do not match. Use DebugStackFrame.eval(String) to evaluate values to be set.
    
    Parameters:
    
    value - the value to set
    
    Since:
    
    0.17
  - as
```
public abstract <T> T as(Class<T> clazz)
```
    Converts the debug value into a Java type. Class conversions which are always supported:
    - String.class converts the value to its language specific string representation.
    No optional conversions are currently available. If a conversion is not supported then an UnsupportedOperationException is thrown. If the value is not readable then an IllegalStateException is thrown.
    Parameters:
    
    clazz - the type to convert to
    
    Returns:
    
    the converted Java type
    
    Since:
    
    0.17
  - getName
```
public abstract String getName()
```
    Returns the name of this value as it is referred to from its origin. If this value is originated from the stack it returns the name of the local variable. If the value was returned from another objects then it returns the name of the property or field it is contained in. If no name is available null is returned.
    
    Since:
    
    0.17
  - isReadable
```
public abstract boolean isReadable()
```
    Returns true if this value can be read else false.
    
    Since:
    
    0.17
    
    See Also:
    
    DebugValue.as(Class)
  - isWritable
```
public abstract boolean isWritable()
```
    Returns true if this value can be written to, else false.
    
    Since:
    
    0.26
    
    See Also:
    
    DebugValue.as(Class)
  - isInternal
```
public abstract boolean isInternal()
```
    Returns true if this value represents an internal implementation detail, false otherwise. Internal values should be hidden during normal guest language debugging.
    Language implementations sometimes create internal helper variables that do not correspond to anything explicitly written by a programmer. Language implementors mark these variables as internal.
    
    Clients of the debugging API should assume that displaying internal values is unlikely to help programmers debug guest language programs and might possibly create confusion. However, clients may choose to display all values, for example in a special mode to support development of programming language implementations.
    
    Since:
    
    0.26
  - getScope
```
public DebugScope getScope()
```
    Get the scope where this value is declared in. It returns a non-null value for local variables declared on a stack. It's null for object properties and other heap values.
    Returns: the scope, or null when this value does not belong into any scope. Since: 0.26
  - getProperties public final Collection<DebugValue> getProperties() Provides properties representing an internal structure of this value. The returned collection is not thread-safe. If the value is not readable then an IllegalStateException is thrown.
    Returns:
    a collection of property values, or null when the value does not have any concept of properties.
    
    Since:
    
    0.19
  - isArray
```
public final boolean isArray()
```
    Returns true if this value represents an array, false otherwise.
    
    Since:
    
    0.19
  - getArray
```
public final List<DebugValue> getArray()
```
    Provides array elements when this value represents an array. To test if this value represents an array, check DebugValue.isArray().
    
    Returns:
    
    a list of array elements, or null when the value does not represent an array.
    
    Since:
    
    0.19
  - getMetaObject
```
public final DebugValue getMetaObject()
```
    Get a meta-object of this value, if any. The meta-object represents a description of the value, reveals it's kind and it's features.
    
    Returns:
    
    a value representing the meta-object, or null
    
    Since:
    
    0.22
  - getSourceLocation
```
public final SourceSection getSourceLocation()
```
    Get a source location where this value is declared, if any.
    
    Returns:
    
    a source location of the object, or null
    
    Since:
    
    0.22
  - toString
```
public String toString()
```
    Returns a string representation of the debug value.
    
    Overrides:
    
    toString in class Object
    
    Since:
    
    0.17

Class DebugValue

Method Summary

Methods inherited from class java.lang.Object

Method Detail

set

as

getName

isReadable

isWritable

isInternal

getScope

getProperties

isArray

getArray

getMetaObject

getSourceLocation

toString