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src/jdk.scripting.nashorn.shell/share/classes/jdk/nashorn/tools/jjs/Main.java
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@@ -29,18 +29,36 @@
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
+import java.util.Iterator;
+import java.util.List;
import java.util.prefs.Preferences;
+import jdk.nashorn.api.tree.AssignmentTree;
+import jdk.nashorn.api.tree.BinaryTree;
+import jdk.nashorn.api.tree.CompilationUnitTree;
+import jdk.nashorn.api.tree.CompoundAssignmentTree;
+import jdk.nashorn.api.tree.ConditionalExpressionTree;
+import jdk.nashorn.api.tree.ExpressionTree;
+import jdk.nashorn.api.tree.ExpressionStatementTree;
+import jdk.nashorn.api.tree.InstanceOfTree;
+import jdk.nashorn.api.tree.MemberSelectTree;
+import jdk.nashorn.api.tree.SimpleTreeVisitorES5_1;
+import jdk.nashorn.api.tree.Tree;
+import jdk.nashorn.api.tree.UnaryTree;
+import jdk.nashorn.api.tree.Parser;
+import jdk.nashorn.api.scripting.NashornException;
import jdk.nashorn.internal.objects.Global;
import jdk.nashorn.internal.runtime.Context;
import jdk.nashorn.internal.runtime.ErrorManager;
import jdk.nashorn.internal.runtime.JSType;
import jdk.nashorn.internal.runtime.ScriptEnvironment;
+import jdk.nashorn.internal.runtime.ScriptObject;
import jdk.nashorn.internal.runtime.ScriptRuntime;
import jdk.nashorn.tools.Shell;
+import jdk.internal.jline.console.completer.Completer;
import jdk.internal.jline.console.UserInterruptException;
/**
* Interactive command line Shell for Nashorn.
*/
@@ -94,12 +112,76 @@
final ScriptEnvironment env = context.getEnv();
final String prompt = bundle.getString("shell.prompt");
final PrintWriter err = context.getErr();
final Global oldGlobal = Context.getGlobal();
final boolean globalChanged = (oldGlobal != global);
+ final Parser parser = Parser.create();
- try (final Console in = new Console(System.in, System.out, PREFS)) {
+ // simple source "tab completer" for nashorn
+ final Completer completer = new Completer() {
+ @Override
+ public int complete(String test, int cursor, List<CharSequence> result) {
+ // check that cursor is at the end of test string. Do not complete in the middle!
+ if (cursor != test.length()) {
+ return cursor;
+ }
+
+ // if it has a ".", then assume it is a member selection expression
+ final int idx = test.lastIndexOf('.');
+ if (idx == -1) {
+ return cursor;
+ }
+
+ // stuff before the last "."
+ final String exprBeforeDot = test.substring(0, idx);
+
+ // Make sure that completed code will have a member expression! Adding ".x" as a
+ // random property/field name selected to make it possible to be a proper member select
+ final ExpressionTree topExpr = getTopLevelExpression(parser, exprBeforeDot + ".x");
+ if (topExpr == null) {
+ // did not parse to be a top level expression, no suggestions!
+ return cursor;
+ }
+
+
+ // Find 'right most' member select expression's start position
+ final int startPosition = (int) getStartOfMemberSelect(topExpr);
+ if (startPosition == -1) {
+ // not a member expression that we can handle for completion
+ return cursor;
+ }
+
+ // The part of the right most member select expression before the "."
+ final String objExpr = test.substring(startPosition, idx);
+
+ // try to evaluate the object expression part as a script
+ Object obj = null;
+ try {
+ obj = context.eval(global, objExpr, global, "<suggestions>");
+ } catch (Exception ignored) {
+ // throw the exception - this is during tab-completion
+ }
+
+ if (obj != null && obj != ScriptRuntime.UNDEFINED) {
+ // where is the last dot? Is there a partial property name specified?
+ final String prefix = test.substring(idx + 1);
+ if (prefix.isEmpty()) {
+ // no user specified "prefix". List all properties of the object
+ result.addAll(PropertiesHelper.getProperties(obj));
+ return cursor;
+ } else {
+ // list of properties matching the user specified prefix
+ result.addAll(PropertiesHelper.getProperties(obj, prefix));
+ return idx + 1;
+ }
+ }
+
+ return cursor;
+ }
+ };
+
+ try (final Console in = new Console(System.in, System.out, PREFS, completer)) {
if (globalChanged) {
Context.setGlobal(global);
}
global.addShellBuiltins();
@@ -145,6 +227,68 @@
}
}
return SUCCESS;
}
+
+ // returns ExpressionTree if the given code parses to a top level expression.
+ // Or else returns null.
+ private ExpressionTree getTopLevelExpression(final Parser parser, final String code) {
+ try {
+ final CompilationUnitTree cut = parser.parse("<code>", code, null);
+ final List<? extends Tree> stats = cut.getSourceElements();
+ if (stats.size() == 1) {
+ final Tree stat = stats.get(0);
+ if (stat instanceof ExpressionStatementTree) {
+ return ((ExpressionStatementTree)stat).getExpression();
+ }
+ }
+ } catch (final NashornException ignored) {
+ // ignore any parser error. This is for completion anyway!
+ // And user will get that error later when the expression is evaluated.
+ }
+
+ return null;
+ }
+
+
+ private long getStartOfMemberSelect(final ExpressionTree expr) {
+ if (expr instanceof MemberSelectTree) {
+ return ((MemberSelectTree)expr).getStartPosition();
+ }
+
+ final Tree rightMostExpr = expr.accept(new SimpleTreeVisitorES5_1<Tree, Void>() {
+ @Override
+ public Tree visitAssignment(final AssignmentTree at, final Void v) {
+ return at.getExpression();
+ }
+
+ @Override
+ public Tree visitCompoundAssignment(final CompoundAssignmentTree cat, final Void v) {
+ return cat.getExpression();
+ }
+
+ @Override
+ public Tree visitConditionalExpression(final ConditionalExpressionTree cet, final Void v) {
+ return cet.getFalseExpression();
+ }
+
+ @Override
+ public Tree visitBinary(final BinaryTree bt, final Void v) {
+ return bt.getRightOperand();
+ }
+
+ @Override
+ public Tree visitInstanceOf(final InstanceOfTree it, final Void v) {
+ return it.getType();
+ }
+
+ @Override
+ public Tree visitUnary(final UnaryTree ut, final Void v) {
+ return ut.getExpression();
+ }
+ }, null);
+
+ return (rightMostExpr instanceof MemberSelectTree)?
+ rightMostExpr.getStartPosition() : -1L;
+ }
}
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