Improve cmd:arithmetica error messages.

CHANGELOG.md

@@ -1,3 +1,3 @@
 ### What's New:
 
-* Added `hasContext` function to expressions. Allows checking if loot context has the required parameter: `if(hasContext("tool"), "Hi", "Bye")`
+* Slightly improved error messages returned by `cmd:arithmetica`.

src/main/java/me/melontini/commander/impl/event/data/types/ExtractionTypes.java

@@ -6,16 +6,15 @@
 import me.melontini.dark_matter.api.data.codecs.ExtraCodecs;
 import net.minecraft.loot.context.LootContextParameter;
 import net.minecraft.util.Identifier;
-
-import java.util.Objects;
+import org.jetbrains.annotations.Nullable;
 
 public class ExtractionTypes {
 
     private static final BiMap<Identifier, LootContextParameter<?>> KNOWN_PARAMETERS = HashBiMap.create();
     public static final Codec<LootContextParameter<?>> CODEC = ExtraCodecs.mapLookup(Identifier.CODEC, KNOWN_PARAMETERS);
 
-    public static LootContextParameter<?> getParameter(Identifier identifier) {
-        return Objects.requireNonNull(KNOWN_PARAMETERS.get(identifier), () -> "No such loot context parameter %s!".formatted(identifier));
+    public static @Nullable LootContextParameter<?> getParameter(Identifier identifier) {
+        return KNOWN_PARAMETERS.get(identifier);
     }
 
     public static void register(LootContextParameter<?> parameter) {

src/main/java/me/melontini/commander/impl/expression/EvalUtils.java

@@ -157,11 +157,19 @@ public static class MapBasedDataAccessor implements DataAccessorIfc {
 
         @Override
         public @Nullable EvaluationValue getData(String variable) {
-            var id = new Identifier(variable.replace("__idcl__", ":"));
+            var r = Identifier.validate(variable.replace("__idcl__", ":"));
+            if (r.error().isPresent()) {
+                throw new CmdEvalException("%s - %s".formatted(variable.replace("__idcl__", ":"), r.error().orElseThrow().message()));
+            }
+
+            var id = r.result().orElseThrow();
             var func = overrides.get(id);
             if (func != null) return CONFIGURATION.getEvaluationValueConverter().convertObject(func.apply(LOCAL.get()), CONFIGURATION);
 
-            var object = LOCAL.get().get(ExtractionTypes.getParameter(id));
+            var param = ExtractionTypes.getParameter(id);
+            if (param == null) throw new CmdEvalException("%s is not a registered loot context parameter!".formatted(id));
+
+            var object = LOCAL.get().get(param);
             if (object == null) return null;
             return CONFIGURATION.getEvaluationValueConverter().convertObject(object, CONFIGURATION);
         }