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* (a) the Software, and
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* is contributed by such licensors),
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package com.oracle.truffle.api.dsl;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import com.oracle.truffle.api.TruffleLanguage.LanguageReference;
import com.oracle.truffle.api.nodes.Node;
Allows to access the current language instance in specializations or exported messages. The parameter type must be the exact type of the language access or a LanguageReference
that provides it. The latter parameter allows to lookup the language lazily, e.g. in a conditional branch. Using this annotation always allows to generate uncached
versions of the node.
This annotation can be used in two different ways:
- Direct language access:
@GenerateUncached
abstract static class ExampleNode extends Node {
abstract Object execute(Object argument);
@Specialization
static int doInt(int value,
@CachedLanguage MyLanguage language) {
// use context
return value;
}
}
- Conditional language access:
@GenerateUncached
abstract class ExampleNode extends Node {
abstract Object execute(Object argument);
@Specialization
static int doInt(int value,
@CachedLanguage LanguageReference ref) {
if (value == 42) {
// use context conditionally
MyLanguage language = ref.get();
}
return value;
}
}
The generated code uses the Node.lookupLanguageReference(Class<TruffleLanguage>)
method to implement this feature. This method may also be used manually.
See Also: Since: 19.0
/**
* Allows to access the current language instance in specializations or exported messages. The
* parameter type must be the exact type of the language access or a {@link LanguageReference} that
* provides it. The latter parameter allows to lookup the language lazily, e.g. in a conditional
* branch. Using this annotation always allows to generate {@link GenerateUncached uncached}
* versions of the node.
* <p>
* This annotation can be used in two different ways:
* <ol>
* <li>Direct language access:</li>
*
* <pre>
* @GenerateUncached
* abstract static class ExampleNode extends Node {
*
* abstract Object execute(Object argument);
*
* @Specialization
* static int doInt(int value,
* @CachedLanguage MyLanguage language) {
* // use context
* return value;
* }
*
* }
* </pre>
*
* <li>Conditional language access:</li>
*
* <pre>
* @GenerateUncached
* abstract class ExampleNode extends Node {
*
* abstract Object execute(Object argument);
*
* @Specialization
* static int doInt(int value,
* @CachedLanguage LanguageReference<MyLanguage> ref) {
* if (value == 42) {
* // use context conditionally
* MyLanguage language = ref.get();
*
* }
* return value;
* }
* }
* </pre>
* </ol>
* <p>
* The generated code uses the {@link Node#lookupLanguageReference(Class)} method to implement this
* feature. This method may also be used manually.
*
* @see Cached @Cached for more information on using this annotation.
* @see CachedContext @CachedContext to access the language instance.
* @since 19.0
*/
@Retention(RetentionPolicy.CLASS)
@Target({ElementType.PARAMETER})
public @interface CachedLanguage {
}