Enum Snippet.Status
- java.lang.Object
-
- java.lang.Enum<Snippet.Status>
-
- jdk.jshell.Snippet.Status
- All Implemented Interfaces:
-
Serializable
,Comparable<Snippet.Status>
- Enclosing class:
- Snippet
public static enum Snippet.Status extends Enum<Snippet.Status>
Describes the current state of a Snippet. This is a dynamic property of a Snippet within the JShell state -- thus is retrieved with a query on {@code 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 the VALID
Status
.
- See Also:
JShell.status(jdk.jshell.Snippet)
Enum Constants
Enum Constant | Description |
---|---|
DROPPED | The snippet is inactive because of an explicit call to the |
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OVERWRITTEN | The snippet is inactive because it has been replaced by a new snippet.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 |
RECOVERABLE_NOT_DEFINED | The snippet is a declaration snippet with potentially recoverable unresolved references or other issues (in the context of current |
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 |
Methods
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 |
boolean | isDefined() | Indicates whether the snippet is currently part of the defined state of the JShell. |
static Snippet.Status | valueOf(String name) | Returns the enum constant of this type with the specified name. |
static Snippet.Status[] | values() | Returns an array containing the constants of this enum type, in the order they are declared. |
Methods declared in class java.lang.Enum
clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf
Methods declared in class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait
Enum Constants
VALID
public static final Snippet.Status VALID
The snippet is a valid snippet (in the context of current 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
.
RECOVERABLE_DEFINED
public static final Snippet.Status 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). 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.
RECOVERABLE_NOT_DEFINED
public static final Snippet.Status RECOVERABLE_NOT_DEFINED
The snippet is a declaration snippet with potentially recoverable unresolved references or other issues (in the context of current 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.
DROPPED
public static final Snippet.Status DROPPED
The snippet is inactive because of an explicit call to the 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.
OVERWRITTEN
public static final Snippet.Status OVERWRITTEN
The snippet is inactive because it has been replaced by a new snippet. This occurs when the new snippet added with 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.
REJECTED
public static final Snippet.Status 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.
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.
NONEXISTENT
public static final Snippet.Status NONEXISTENT
The snippet is inactive because it does not yet exist. Used only in SnippetEvent.previousStatus
for new snippets. JShell.status(Snippet)
will never return this Status
.
Vacuously, isDefined()
and isActive()
are both defined false
.
Methods
values
public static Snippet.Status[] values()
Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:
for (Snippet.Status c : Snippet.Status.values()) System.out.println(c);
- Returns:
- an array containing the constants of this enum type, in the order they are declared
valueOf
public static Snippet.Status valueOf(String name)
Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
- Parameters:
-
name
- the name of the enum constant to be returned. - Returns:
- the enum constant with the specified name
- Throws:
-
IllegalArgumentException
- if this enum type has no constant with the specified name -
NullPointerException
- if the argument is null
isActive
public 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. This is more broad than isDefined()
since a Snippet which is RECOVERABLE_NOT_DEFINED
will be updated.
- Returns:
-
true
if the Snippet is active; otherwisefalse
isDefined
public boolean isDefined()
Indicates whether the snippet is currently part of the defined state of the JShell. Is it visible to compilation of other snippets?
- Returns:
-
true
if the Snippet is defined; otherwisefalse
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https://docs.oracle.com/en/java/javase/11/docs/api/jdk.jshell/jdk/jshell/Snippet.Status.html