org.fuwjin.chessur.Script Maven / Gradle / Ivy
package org.fuwjin.chessur;
import java.io.PrintStream;
import java.io.Writer;
import javax.script.ScriptException;
import org.fuwjin.grin.env.Trace;
/**
* The executable script interface. Script executions have four central pieces
* to their state: an input source, an output sink, an environment map, and a
* return value.
*
* The input source may be either an InputStream or a Reader. If the source is
* an InputStream, then it will read bytes from the input. If the source is a
* Reader, then Unicode code points will be read from the input.
*
* The output sink may be either a PrintStream or a Writer. If the sink is a
* PrintStream, then it will use the {@link PrintStream#print(Object)} method to
* append to the stream. If the sink is a Writer, then it will use
* {@link Writer#write(String)} to write objects which have been turned to
* strings through the {@link String#valueOf(Object)} method.
*
* The environment map provides the initial set of variable references to the
* script. Note that this environment map may not be altered by the script.
*
* The return value is the Java-realized object returned from the script, or
* null if there was no return statement in the script.
*/
public interface Script {
Object eval(Trace trace) throws ScriptException;
/**
* Returns a name for this script. Note that the same underlying script may
* have different names depending on how it was acquired.
* @return the name
*/
String name();
}