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package jdk.jshell.spi;

import java.util.Collections;
import java.util.Map;

The provider used by JShell to generate the execution engine needed to
evaluate Snippets.  Alternate execution engines can be created by
implementing this interface, then configuring JShell with the provider or
the providers name and parameter specifier.
Author:
Robert Field
Since:
9/**
 * The provider used by JShell to generate the execution engine needed to
 * evaluate Snippets.  Alternate execution engines can be created by
 * implementing this interface, then configuring JShell with the provider or
 * the providers name and parameter specifier.
 *
 * @author Robert Field
 * @since 9
 */
public interface ExecutionControlProvider {

    
The unique name of this ExecutionControlProvider. The name must be a sequence of characters from the Basic Multilingual Plane which are Character.isJavaIdentifierPart(char). 
Returns:
the ExecutionControlProvider's name/**
     * The unique name of this {@code ExecutionControlProvider}.  The name must
     * be a sequence of characters from the Basic Multilingual Plane which are
     * {@link Character#isJavaIdentifierPart(char) }.
     *
     * @return the ExecutionControlProvider's name
     */
    String name();

    
Create and return the default parameter map for this ExecutionControlProvider. The map can optionally be modified; Modified or unmodified it can be passed to generate(ExecutionEnv, Map<String,String>). 
Returns:
the default parameter map/**
     * Create and return the default parameter map for this
     * {@code ExecutionControlProvider}. The map can optionally be modified;
     * Modified or unmodified it can be passed to
     * {@link #generate(jdk.jshell.spi.ExecutionEnv, java.util.Map) }.
     *
     * @return the default parameter map
     */
    default Map<String,String> defaultParameters() {
        return Collections.emptyMap();
    }

    
Create and return the ExecutionControl instance. 
Params:
env – the execution environment, provided by JShell
parameters – the default or modified parameter map.
Throws:
Throwable – an exception that occurred attempting to create the
execution engine.
Returns:
the execution engine/**
     * Create and return the {@code ExecutionControl} instance.
     *
     * @param env the execution environment, provided by JShell
     * @param parameters the {@linkplain #defaultParameters() default} or
     * modified parameter map.
     * @return the execution engine
     * @throws Throwable an exception that occurred attempting to create the
     * execution engine.
     */
    ExecutionControl generate(ExecutionEnv env, Map<String,String> parameters)
            throws Throwable;
}