Module jdk.jshell

Package jdk.jshell

Class SnippetEvent

java.lang.Object

jdk.jshell.SnippetEvent

public class SnippetEvent
extends Object

A description of a change to a Snippet. These are generated by direct changes to state with JShell.eval(String) or JShell.drop(PersistentSnippet), or indirectly by these same methods as dependencies change or Snippets are overwritten. For direct changes, the causeSnippet() is null.

SnippetEvent is immutable: an access to any of its methods will always return the same result. and thus is thread-safe.

Method Summary

Modifier and Type	Method and Description
Snippet	causeSnippet() Either the snippet whose change caused this update or null.
Exception	exception() An instance of UnresolvedReferenceException, if an unresolved reference was encountered, or an instance of EvalException if an exception was thrown during execution, otherwise null.
boolean	isSignatureChange() Has the signature changed? Coming in or out of definition (status.isDefined) is always a signature change.
Snippet.Status	previousStatus() The status before the transition.
Snippet	snippet() The Snippet which has changed
Snippet.Status	status() The after status.
String	toString() Return a string representation of the event
String	value() The result value of successful run.

Methods inherited from class java.lang.Object

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

Method Detail

snippet

public Snippet snippet()

The Snippet which has changed

Returns:

the return the Snippet whose Status has changed.

previousStatus

public Snippet.Status previousStatus()

The status before the transition. If this event describes a Snippet creation return NONEXISTENT.

Returns:

the previousStatus

status

public Snippet.Status status()

The after status. Note: this may be the same as the previous status (not all changes cause a Status change.

Returns:

the status

isSignatureChange

public boolean isSignatureChange()

Has the signature changed? Coming in or out of definition (status.isDefined) is always a signature change. An overwritten Snippet (status == OVERWRITTEN) is always false as responsibility for the definition has passed to the overwriting definition.

Returns:

true if the signature changed.

causeSnippet

public Snippet causeSnippet()

Either the snippet whose change caused this update or null. This returns null if this change is the creation of a new Snippet via eval or it is the explicit drop of a Snippet with drop.

Returns:

the Snippet which caused this change or null if directly caused by an API action.

exception

public Exception exception()

An instance of UnresolvedReferenceException, if an unresolved reference was encountered, or an instance of EvalException if an exception was thrown during execution, otherwise null.

Returns:

the exception or null.

value

public String value()

The result value of successful run. The value is null if not executed or an exception was thrown.

Returns:

the value or null.

toString

public String toString()

Return a string representation of the event

Overrides:

toString in class Object

Returns:

a descriptive representation of the SnippetEvent