ScriptREPL: implement a local debug mode

Instead of asking the LogService for whether it is in debug mode,
let's just have our own debug flag, which can be toggled via the
REPL itself. This is more convenient for the REPL user.

Author: ctrueden

src/main/java/org/scijava/script/ScriptREPL.java

@@ -46,7 +46,6 @@
 
 import org.scijava.Context;
 import org.scijava.Gateway;
-import org.scijava.log.LogService;
 import org.scijava.plugin.Parameter;
 import org.scijava.plugin.PluginInfo;
 import org.scijava.plugin.PluginService;
@@ -70,9 +69,6 @@ public class ScriptREPL {
 	@Parameter(required = false)
 	private PluginService pluginService;
 
-	@Parameter(required = false)
-	private LogService log;
-
 	private final PrintStream out;
 
 	/** List of interpreter-friendly script languages. */
@@ -81,6 +77,9 @@ public class ScriptREPL {
 	/** The currently active interpreter. */
 	private ScriptInterpreter interpreter;
 
+	/** Flag for debug mode. */
+	private boolean debug;
+
 	public ScriptREPL(final Context context) {
 		this(context, System.out);
 	}
@@ -172,6 +171,7 @@ public boolean evaluate(final String line) {
 			if (tLine.equals(":help")) help();
 			else if (tLine.equals(":vars")) vars();
 			else if (tLine.equals(":langs")) langs();
+			else if (tLine.equals(":debug")) debug();
 			else if (tLine.startsWith(":lang ")) lang(line.substring(6).trim());
 			else if (tLine.equals(":quit")) return false;
 			else {
@@ -188,7 +188,7 @@ public boolean evaluate(final String line) {
 		catch (final ScriptException exc) {
 			// NB: Something went wrong interpreting the line of code.
 			// Let's just display the error message, unless we are in debug mode.
-			if (log.isDebug()) exc.printStackTrace(out);
+			if (debug) exc.printStackTrace(out);
 			else {
 				final String msg = exc.getMessage();
 				out.println(msg == null ? exc.getClass().getName() : msg);
@@ -211,6 +211,7 @@ public void help() {
 		out.println("  :vars           | dump a list of variables");
 		out.println("  :lang <name>    | switch the active language");
 		out.println("  :langs          | list available languages");
+		out.println("  :debug          | toggle full stack traces");
 		out.println("  :quit           | exit the REPL");
 		out.println();
 		out.println("Or type a statement to evaluate it with the active language.");
@@ -269,6 +270,11 @@ public void langs() {
 		printColumns(names, versions, aliases);
 	}
 
+	public void debug() {
+		debug = !debug;
+		out.println("debug mode -> " + debug);
+	}
+
 	// -- Main method --
 
 	public static void main(final String... args) throws Exception {