handled better errors and stack traces for more (all) cases

src/main/java/carpet/commands/ScriptCommand.java

@@ -276,16 +276,19 @@ public class ScriptCommand
     }
     private static CarpetScriptHost getHost(CommandContext<ServerCommandSource> context)
     {
+        CarpetScriptHost host;
         try
         {
             String name = StringArgumentType.getString(context, "app").toLowerCase(Locale.ROOT);
             CarpetScriptHost parentHost = CarpetServer.scriptServer.modules.getOrDefault(name, CarpetServer.scriptServer.globalHost);
-            return parentHost.retrieveForExecution(context.getSource());
+            host =  parentHost.retrieveForExecution(context.getSource());
         }
         catch (IllegalArgumentException ignored)
         {
-            return CarpetServer.scriptServer.globalHost;
+            host =  CarpetServer.scriptServer.globalHost;
         }
+        host.setChatErrorSnooper(context.getSource());
+        return host;
     }
     private static Collection<String> suggestFunctionCalls(CommandContext<ServerCommandSource> c)
     {
@@ -324,7 +327,6 @@ public class ScriptCommand
                 Messenger.m(source, "gi ----------------");
                 return;
             }
-            CarpetSettings.LOG.error("printing function "+fun.getPrettyString());
             Expression expr = fun.getExpression();
             Tokenizer.Token tok = fun.getToken();
             List<String> snippet = ExpressionInspector.Expression_getExpressionSnippet(tok, expr);
@@ -375,10 +377,9 @@ public class ScriptCommand
         }
         catch (CarpetExpressionException e)
         {
-            e.printStack(source);
-            Messenger.m(source, "r Exception while evaluating expression at "+new BlockPos(source.getPosition())+": "+e.getMessage());
+            host.handleErrorWithStack("Error while evaluating expression", e);
         }
-        host.resetErrorSnooper();
+        //host.resetErrorSnooper();  // lets say no need to reset the snooper in case something happens on the way
     }
 
     private static int invoke(CommandContext<ServerCommandSource> context, String call, BlockPos pos1, BlockPos pos2,  String args)
@@ -457,8 +458,7 @@ public class ScriptCommand
         }
         catch (CarpetExpressionException exc)
         {
-            exc.printStack(source);
-            Messenger.m(source, "r Error while processing command: "+exc);
+            host.handleErrorWithStack("Error while processing command", exc);
             return 0;
         }
         finally
@@ -505,8 +505,7 @@ public class ScriptCommand
                     }
                     catch (CarpetExpressionException e)
                     {
-                        e.printStack(source);
-                        Messenger.m(source, "r Exception while filling the area:\n","l "+e.getMessage());
+                        host.handleErrorWithStack("Exception while filling the area", e);
                         return 0;
                     }
                     catch (ArithmeticException e)

src/main/java/carpet/script/CarpetScriptHost.java

@@ -32,6 +32,7 @@ import static java.lang.Math.max;
 public class CarpetScriptHost extends ScriptHost
 {
     private final CarpetScriptServer scriptServer;
+    ServerCommandSource responsibleSource;
 
     private Tag globalState;
     private int saveTimeout;
@@ -66,8 +67,7 @@ public class CarpetScriptHost extends ScriptHost
             }
             catch (CarpetExpressionException e)
             {
-                e.printStack(source);
-                Messenger.m(source, "r Exception while evaluating expression at " + new BlockPos(source.getPosition()) + ": " + e.getMessage());
+                host.handleErrorWithStack("Error while evaluating expression", e);
                 host.resetErrorSnooper();
                 return null;
             }
@@ -129,16 +129,33 @@ public class CarpetScriptHost extends ScriptHost
 
     public CarpetScriptHost retrieveForExecution(ServerCommandSource source)
     {
-        if (!perUser)
-            return this;
+        CarpetScriptHost host = this;
+        if (perUser)
+        {
+            try
+            {
+                ServerPlayerEntity player = source.getPlayer();
+                host = (CarpetScriptHost) retrieveForExecution(player.getName().getString());
+            }
+            catch (CommandSyntaxException e)
+            {
+                host = (CarpetScriptHost)  retrieveForExecution((String) null);
+            }
+        }
+        if (host.errorSnooper == null) host.setChatErrorSnooper(source);
+        return host;
+    }
+
+    public String handleCommand(ServerCommandSource source, String call, List<Integer> coords, String arg)
+    {
         try
         {
-            ServerPlayerEntity player = source.getPlayer();
-            return (CarpetScriptHost) retrieveForExecution(player.getName().getString());
+            return call(source, call, coords, arg);
         }
-        catch (CommandSyntaxException e)
+        catch (CarpetExpressionException exc)
         {
-            return (CarpetScriptHost) retrieveForExecution((String)null);
+            handleErrorWithStack("Error while running custom command", exc);
+            return "";
         }
     }
 
@@ -236,7 +253,7 @@ public class CarpetScriptHost extends ScriptHost
         }
         catch (ExpressionException e)
         {
-            return e.getMessage();
+            throw new CarpetExpressionException(e.getMessage(), e.stack);
         }
     }
 
@@ -259,7 +276,7 @@ public class CarpetScriptHost extends ScriptHost
         }
         catch (ExpressionException e)
         {
-            CarpetSettings.LOG.error("Callback failed: "+e.getMessage());
+            handleExpressionException("Callback failed", e);
         }
         return Value.NULL;
     }
@@ -361,6 +378,7 @@ public class CarpetScriptHost extends ScriptHost
 
     public void setChatErrorSnooper(ServerCommandSource source)
     {
+        responsibleSource = source;
         errorSnooper = (expr, /*Nullable*/ token, message) ->
         {
             try
@@ -412,4 +430,31 @@ public class CarpetScriptHost extends ScriptHost
             return new ArrayList<>();
         };
     }
+
+    @Override
+    public void resetErrorSnooper()
+    {
+        responsibleSource = null;
+        super.resetErrorSnooper();
+    }
+
+    public void handleErrorWithStack(String intro, CarpetExpressionException exception)
+    {
+        if (responsibleSource != null)
+        {
+            exception.printStack(responsibleSource);
+            String message = exception.getMessage();
+            Messenger.m(responsibleSource, "r "+intro+(message.isEmpty()?"":": "+message));
+        }
+        else
+        {
+            CarpetSettings.LOG.error(intro+": "+exception.getMessage());
+        }
+    }
+
+    @Override
+    public void handleExpressionException(String message, ExpressionException exc)
+    {
+        handleErrorWithStack(message, new CarpetExpressionException(exc.getMessage(), exc.stack));
+    }
 }

src/main/java/carpet/script/CarpetScriptServer.java

@@ -220,7 +220,7 @@ public class CarpetScriptServer
                 executes( (c) ->
                 {
                     String response = modules.get(hostName).retrieveForExecution(c.getSource()).
-                            call(c.getSource(),"__command", null, "");
+                            handleCommand(c.getSource(),"__command", null, "");
                     if (!response.isEmpty()) Messenger.m(c.getSource(), "gi "+response);
                     return 1;
                 });
@@ -232,14 +232,14 @@ public class CarpetScriptServer
                             requires((player) -> modules.containsKey(hostName) && modules.get(hostName).getFunction(function) != null).
                             executes( (c) -> {
                                 String response = modules.get(hostName).retrieveForExecution(c.getSource()).
-                                        call(c.getSource(), function,null,"");
+                                        handleCommand(c.getSource(), function,null,"");
                                 if (!response.isEmpty()) Messenger.m(c.getSource(),"gi "+response);
                                 return 1;
                             }).
                             then(argument("args...", StringArgumentType.greedyString()).
                                     executes( (c) -> {
                                         String response = modules.get(hostName).retrieveForExecution(c.getSource()).
-                                                call(c.getSource(), function,null, StringArgumentType.getString(c, "args..."));
+                                                handleCommand(c.getSource(), function,null, StringArgumentType.getString(c, "args..."));
                                         if (!response.isEmpty()) Messenger.m(c.getSource(), "gi "+response);
                                         return 1;
                                     })));

src/main/java/carpet/script/ScriptHost.java

@@ -1,6 +1,7 @@
 package carpet.script;
 
 import carpet.script.bundled.Module;
+import carpet.script.exception.ExpressionException;
 import carpet.script.exception.InternalExpressionException;
 import carpet.script.value.FunctionValue;
 import carpet.script.value.Value;
@@ -313,6 +314,12 @@ public abstract class ScriptHost
         return userHost;
     }
 
+    public void handleExpressionException(String msg, ExpressionException exc)
+    {
+        System.out.println(msg+": "+exc);
+    }
+
+
     protected abstract ScriptHost duplicate();
 
     public void onClose() { }

src/main/java/carpet/script/value/FunctionValue.java

@@ -68,7 +68,7 @@ public class FunctionValue extends Value implements Fluff.ILazyFunction
         return (name.equals("_")?"<lambda>":name) +"("+String.join(", ",stringArgs)+")";
     }
 
-    public String fullName() {return expression.module == null?name:name+"["+expression.module.getName()+"]";}
+    public String fullName() {return (name.equals("_")?"<lambda>":name)+(expression.module == null?"":"["+expression.module.getName()+"]");}
 
     @Override
     public boolean getBoolean()

src/main/java/carpet/script/value/ThreadValue.java

@@ -4,6 +4,7 @@ import carpet.script.Context;
 import carpet.script.Expression;
 import carpet.script.LazyValue;
 import carpet.script.Tokenizer;
+import carpet.script.exception.ExpressionException;
 import carpet.script.exception.InternalExpressionException;
 
 import java.util.HashMap;
@@ -29,7 +30,18 @@ public class ThreadValue extends Value
     {
         id = sequence++;
         taskFuture = CompletableFuture.supplyAsync(
-            () -> function.lazyEval(ctx, Context.NONE, expr, token, args).evalValue(ctx),
+            () ->
+            {
+                try
+                {
+                    return function.lazyEval(ctx, Context.NONE, expr, token, args).evalValue(ctx);
+                }
+                catch (ExpressionException exc)
+                {
+                    ctx.host.handleExpressionException("Thread failed", exc);
+                    return Value.NULL;
+                }
+            },
             executorServices.computeIfAbsent(pool, (v) -> (ThreadPoolExecutor)Executors.newCachedThreadPool())
         );
         Thread.yield();