Add cell command to load a B machine from the notebook

src/main/java/de/prob2/jupyter/ProBKernel.java

@@ -10,6 +10,7 @@ import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import com.google.inject.Inject;
+import com.google.inject.Injector;
 
 import de.prob.animator.domainobjects.AbstractEvalResult;
 import de.prob.animator.domainobjects.FormulaExpand;
@@ -21,6 +22,7 @@ import de.prob2.jupyter.commands.CommandExecutionException;
 import de.prob2.jupyter.commands.EchoCellCommand;
 import de.prob2.jupyter.commands.HelpCommand;
 import de.prob2.jupyter.commands.LineCommand;
+import de.prob2.jupyter.commands.LoadCellCommand;
 import de.prob2.jupyter.commands.NoSuchCommandException;
 
 import io.github.spencerpark.jupyter.kernel.BaseKernel;
@@ -38,7 +40,7 @@ public final class ProBKernel extends BaseKernel {
 	private @NotNull Trace trace;
 	
 	@Inject
-	private ProBKernel(final @NotNull ClassicalBFactory classicalBFactory) {
+	private ProBKernel(final @NotNull Injector injector, final @NotNull ClassicalBFactory classicalBFactory) {
 		super();
 		
 		this.lineCommands = new HashMap<>();
@@ -48,6 +50,7 @@ public final class ProBKernel extends BaseKernel {
 		
 		this.cellCommands = new HashMap<>();
 		this.cellCommands.put("::echo", new EchoCellCommand());
+		this.cellCommands.put("::load", injector.getInstance(LoadCellCommand.class));
 		
 		this.trace = new Trace(classicalBFactory.create("MACHINE repl END").load());
 	}
@@ -60,6 +63,14 @@ public final class ProBKernel extends BaseKernel {
 		return Collections.unmodifiableMap(this.lineCommands);
 	}
 	
+	public @NotNull Trace getTrace() {
+		return this.trace;
+	}
+	
+	public void setTrace(final @NotNull Trace trace) {
+		this.trace = trace;
+	}
+	
 	@Override
 	public @NotNull String getBanner() {
 		return "ProB Interactive Expression and Predicate Evaluator (on Jupyter)\nType \":help\" for more information.";

src/main/java/de/prob2/jupyter/commands/LoadCellCommand.java

+package de.prob2.jupyter.commands;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import com.google.inject.Inject;
+
+import de.prob.scripting.ClassicalBFactory;
+import de.prob.statespace.Trace;
+
+import de.prob2.jupyter.ProBKernel;
+
+import io.github.spencerpark.jupyter.messages.DisplayData;
+
+import org.jetbrains.annotations.NotNull;
+
+public final class LoadCellCommand implements CellCommand {
+	private final @NotNull ClassicalBFactory classicalBFactory;
+	
+	@Inject
+	private LoadCellCommand(final @NotNull ClassicalBFactory classicalBFactory) {
+		super();
+		
+		this.classicalBFactory = classicalBFactory;
+	}
+	
+	@Override
+	public @NotNull String getSyntax() {
+		return "::load\nMACHINE\n...\nEND";
+	}
+	
+	@Override
+	public @NotNull String getShortHelp() {
+		return "Load the machine source code from the body.";
+	}
+	
+	@Override
+	public @NotNull DisplayData run(final @NotNull ProBKernel kernel, final @NotNull String name, final @NotNull List<@NotNull String> args, final @NotNull String body) {
+		final Map<String, String> preferences = new HashMap<>();
+		for (final String arg : args) {
+			final String[] split = arg.split("=", 2);
+			if (split.length == 1) {
+				throw new CommandExecutionException(name, "Missing value for preference " + split[0]);
+			}
+			preferences.put(split[0], split[1]);
+		}
+		
+		kernel.setTrace(new Trace(this.classicalBFactory.create(body).load(preferences)));
+		return new DisplayData("Loaded machine: " + kernel.getTrace().getModel());
+	}
+}