Serializable
, Comparable<Snippet.Status>
, Constable
Snippet
public static enum Snippet.Status extends Enum<Snippet.Status>
JShell
. The Status
changes as the state changes. For example, creation of another snippet with eval
may resolve dependencies of this Snippet (or invalidate those dependencies), or overwrite this Snippet changing its Status
.
Important properties associated with Status
are: isDefined()
, if it is visible to other existing and new snippets; and isActive()
, if, as the JShell state changes, the snippet will update, possibly changing Status
. An executable Snippet can only be executed if it is in the VALID
Status
.
Enum.EnumDesc<E extends Enum<E>>
Enum Constant | Description |
---|---|
DROPPED |
The snippet is inactive because of an explicit call to the JShell.drop(Snippet) . |
NONEXISTENT |
The snippet is inactive because it does not yet exist. |
OVERWRITTEN |
The snippet is inactive because it has been replaced by a new snippet. |
RECOVERABLE_DEFINED |
The snippet is a declaration snippet with potentially recoverable unresolved references or other issues in its body (in the context of current JShell state). |
RECOVERABLE_NOT_DEFINED |
The snippet is a declaration snippet with potentially recoverable unresolved references or other issues (in the context of current JShell state). |
REJECTED |
The snippet is inactive because it failed compilation on initial evaluation and it is not capable of becoming valid with further changes to the JShell state. |
VALID |
The snippet is a valid snippet (in the context of current JShell state). |
Modifier and Type | Method | Description |
---|---|---|
boolean |
isActive() |
Indicates whether the Snippet is active, that is, will a persistent snippet be re-evaluated when a new JShell.eval(String) or JShell.drop(Snippet) that could change its status is invoked. |
boolean |
isDefined() |
Indicates whether the snippet is currently part of the defined state of the JShell. |
static Snippet.Status |
valueOf |
Returns the enum constant of this class with the specified name. |
static Snippet.Status[] |
values() |
Returns an array containing the constants of this enum class, in the order they are declared. |
public static final Snippet.Status VALID
JShell
state). Only snippets with VALID
Status
can be executed (though not all VALID
snippets have executable code). The snippet is defined (isDefined() == true
). If the snippet is a declaration or import (Snippet.Kind.isPersistent()
), it is visible to other snippets
The snippet will update as dependents change (isActive() == true
), its status could become RECOVERABLE_DEFINED
, RECOVERABLE_NOT_DEFINED
, DROPPED
, or OVERWRITTEN
.
public static final Snippet.Status RECOVERABLE_DEFINED
JShell
state). Only a DeclarationSnippet
can have this Status
. The snippet has a valid signature and it is visible to other snippets (isDefined() == true
) and thus can be referenced in existing or new snippets but the snippet cannot be executed. An UnresolvedReferenceException
will be thrown on an attempt to execute it.
The snippet will update as dependents change (isActive() == true
), its status could become VALID
, RECOVERABLE_NOT_DEFINED
, DROPPED
, or OVERWRITTEN
.
Note: both RECOVERABLE_DEFINED
and RECOVERABLE_NOT_DEFINED
indicate potentially recoverable errors, they differ in that, for RECOVERABLE_DEFINED
, the snippet is defined.
public static final Snippet.Status RECOVERABLE_NOT_DEFINED
JShell
state). Only a DeclarationSnippet
can have this Status
. The snippet has an invalid signature or the implementation is otherwise unable to define it. The snippet it is not visible to other snippets (isDefined() == false
) and thus cannot be referenced or executed.
The snippet will update as dependents change (isActive() == true
), its status could become VALID
, RECOVERABLE_DEFINED
, DROPPED
, or OVERWRITTEN
.
Note: both RECOVERABLE_DEFINED
and RECOVERABLE_NOT_DEFINED
indicate potentially recoverable errors, they differ in that, for RECOVERABLE_DEFINED
, the snippet is defined.
public static final Snippet.Status DROPPED
JShell.drop(Snippet)
. The snippet is not visible to other snippets (isDefined() == false
) and thus cannot be referenced or executed.
The snippet will not update as dependents change (isActive() == false
), its Status
will never change again.
public static final Snippet.Status OVERWRITTEN
eval
matches a previous snippet. A TypeDeclSnippet
will match another TypeDeclSnippet
if the names match. For example class X { }
will overwrite class X { int ii; }
or interface X { }
. A MethodSnippet
will match another MethodSnippet
if the names and parameter types match. For example void m(int a) { }
will overwrite int m(int a) { return a+a; }
. A VarSnippet
will match another VarSnippet
if the names match. For example double z;
will overwrite long z = 2L;
. Only a PersistentSnippet
can have this Status
. The snippet is not visible to other snippets (isDefined() == false
) and thus cannot be referenced or executed.
The snippet will not update as dependents change (isActive() == false
), its Status
will never change again.
public static final Snippet.Status REJECTED
The snippet is not visible to other snippets (isDefined() == false
) and thus cannot be referenced or executed.
The snippet will not update as dependents change (isActive() == false
), its Status
will never change again.
public static final Snippet.Status NONEXISTENT
SnippetEvent.previousStatus
for new snippets. JShell.status(Snippet)
will never return this Status
. Vacuously, isDefined()
and isActive()
are both defined false
.
public static Snippet.Status[] values()
public static Snippet.Status valueOf(String name)
name
- the name of the enum constant to be returned.IllegalArgumentException
- if this enum class has no constant with the specified nameNullPointerException
- if the argument is nullpublic boolean isActive()
JShell.eval(String)
or JShell.drop(Snippet)
that could change its status is invoked. This is more broad than isDefined()
since a Snippet which is RECOVERABLE_NOT_DEFINED
will be updated.true
if the Snippet is active; otherwise false
public boolean isDefined()
true
if the Snippet is defined; otherwise false
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/21/docs/api/jdk.jshell/jdk/jshell/Snippet.Status.html