refactored and reworked functions in scarpet

src/main/java/carpet/fakes/EntityInterface.java

@@ -2,7 +2,7 @@ package carpet.fakes;
 
 import carpet.script.CarpetContext;
 import carpet.script.CarpetEventServer;
-import carpet.script.ScriptHost;
+import carpet.script.value.FunctionValue;
 import carpet.script.value.Value;
 import net.minecraft.entity.damage.DamageSource;
 
@@ -13,10 +13,10 @@ public interface EntityInterface
     float getMainYaw(float partialTicks);
     //scarpet part
     void onDeathCallback(String reason);
-    void setDeathCallback(CarpetContext cc, String function, List<Value> extraArgs);
+    void setDeathCallback(CarpetContext cc, FunctionValue function, List<Value> extraArgs);
     void onDamageCallback(float amount, DamageSource source);
-    void setDamageCallback(CarpetContext cc, String function, List<Value> extraArgs);
+    void setDamageCallback(CarpetContext cc, FunctionValue function, List<Value> extraArgs);
-    void setRemovedCallback(CarpetContext cc, String function, List<Value> extraArgs);
+    void setRemovedCallback(CarpetContext cc, FunctionValue function, List<Value> extraArgs);
-    void setTickCallback(CarpetContext cc, String function, List<Value> extraArgs);
+    void setTickCallback(CarpetContext cc, FunctionValue function, List<Value> extraArgs);
     CarpetEventServer.ScheduledCall getTickCallback();
 }

src/main/java/carpet/mixins/Entity_scarpetEventsMixin.java

@@ -4,12 +4,10 @@ import carpet.CarpetServer;
 import carpet.fakes.EntityInterface;
 import carpet.script.CarpetContext;
 import carpet.script.CarpetEventServer;
-import carpet.script.ScriptHost;
+import carpet.script.value.FunctionValue;
 import carpet.script.value.Value;
-import carpet.settings.CarpetSettings;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.damage.DamageSource;
-import org.lwjgl.system.CallbackI;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
 import org.spongepowered.asm.mixin.injection.At;
@@ -27,23 +25,20 @@ public abstract class Entity_scarpetEventsMixin implements EntityInterface
     private CarpetEventServer.ScheduledCall tickCall;
     private CarpetEventServer.ScheduledCall damageCall;
 
-
-
-
     @Override
-    public void setDeathCallback(CarpetContext cc, String function, List<Value> extraArgs)
+    public void setDeathCallback(CarpetContext cc, FunctionValue function, List<Value> extraArgs)
     {
         deathCall = CarpetServer.scriptServer.events.makeDeathCall(cc, function, extraArgs);
     }
 
     @Override
-    public void setRemovedCallback(CarpetContext cc, String function, List<Value> extraArgs)
+    public void setRemovedCallback(CarpetContext cc, FunctionValue function, List<Value> extraArgs)
     {
         removeCall = CarpetServer.scriptServer.events.makeRemovedCall(cc, function, extraArgs);
     }
 
     @Override
-    public void setTickCallback(CarpetContext cc, String function, List<Value> extraArgs)
+    public void setTickCallback(CarpetContext cc, FunctionValue function, List<Value> extraArgs)
     {
         tickCall = CarpetServer.scriptServer.events.makeTickCall(cc, function, extraArgs);
     }
@@ -55,7 +50,7 @@ public abstract class Entity_scarpetEventsMixin implements EntityInterface
     }
 
     @Override
-    public void setDamageCallback(CarpetContext cc, String function, List<Value> extraArgs)
+    public void setDamageCallback(CarpetContext cc, FunctionValue function, List<Value> extraArgs)
     {
         damageCall = CarpetServer.scriptServer.events.makeDamageCall(cc, function, extraArgs);
     }

src/main/java/carpet/script/CarpetEventServer.java

@@ -3,6 +3,7 @@ package carpet.script;
 import carpet.CarpetServer;
 import carpet.script.value.BlockValue;
 import carpet.script.value.EntityValue;
+import carpet.script.value.FunctionValue;
 import carpet.script.value.ListValue;
 import carpet.script.value.NumericValue;
 import carpet.script.value.StringValue;
@@ -19,6 +20,7 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Direction;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.dimension.DimensionType;
+import org.apache.commons.lang3.tuple.Pair;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -39,9 +41,9 @@ public class CarpetEventServer
     public static class Callback
     {
         public String host;
-        public String udf;
+        public FunctionValue udf;
 
-        public Callback(String host, String udf)
+        public Callback(String host, FunctionValue udf)
         {
             this.host = host;
             this.udf = udf;
@@ -50,7 +52,7 @@ public class CarpetEventServer
         @Override
         public String toString()
         {
-            return udf+((host==null)?"":"(from "+host+")");
+            return udf.getString()+((host==null)?"":"(from "+host+")");
         }
     }
 
@@ -61,7 +63,7 @@ public class CarpetEventServer
         public BlockPos context_origin;
         public long dueTime;
 
-        public ScheduledCall(CarpetContext context, String udf, List<LazyValue> args, long dueTime)
+        public ScheduledCall(CarpetContext context, FunctionValue udf, List<LazyValue> args, long dueTime)
         {
             super(context.host.getName(), udf);
             this.args = args;
@@ -119,7 +121,7 @@ public class CarpetEventServer
                 // impossible call to add
                 return false;
             }
-            UserDefinedFunction udf = host.globalFunctions.get(funName);
+            FunctionValue udf = host.globalFunctions.get(funName);
             if (udf == null || udf.getArguments().size() != reqArgs)
             {
                 // call won't match arguments
@@ -127,13 +129,13 @@ public class CarpetEventServer
             }
             //all clear
             //remove duplicates
-            removeEventCall(hostName, funName);
+            removeEventCall(hostName, udf.getString());
-            callList.add(new Callback(hostName, funName));
+            callList.add(new Callback(hostName, udf));
             return true;
         }
-        public void removeEventCall(String hostName, String callName)
+        public void removeEventCall(String hostName, String funName)
         {
-            callList.removeIf((c)->  c.udf.equalsIgnoreCase(callName) && ( hostName == null || c.host.equalsIgnoreCase(hostName) ) );
+            callList.removeIf((c)->  c.udf.getString().equals(funName) && ( hostName == null || c.host.equalsIgnoreCase(hostName) ) );
         }
 
         public void removeAllCalls(String hostName)
@@ -445,7 +447,7 @@ public class CarpetEventServer
         }
 
     }
-    public void scheduleCall(CarpetContext context, String function, List<LazyValue> args, long due)
+    public void scheduleCall(CarpetContext context, FunctionValue function, List<LazyValue> args, long due)
     {
         scheduledCalls.add(new ScheduledCall(context, function, args, due));
     }
@@ -464,8 +466,8 @@ public class CarpetEventServer
 
         if (!Event.byName.containsKey(event))
             return false;
-        Callback callback= decodeCallback(funName);
+        Pair<String,String> call = decodeCallback(funName);
-        Event.byName.get(event).handler.removeEventCall(callback.host, callback.udf);
+        Event.byName.get(event).handler.removeEventCall(call.getLeft(), call.getRight());
         return true;
     }
 
@@ -474,21 +476,20 @@ public class CarpetEventServer
         Event.byName.values().forEach((e) -> e.handler.removeAllCalls(hostName));
     }
 
-    private Callback decodeCallback(String funName)
+    private Pair<String,String> decodeCallback(String funName)
     {
         Pattern find = Pattern.compile("(\\w+)\\(from (\\w+)\\)");
         Matcher matcher = find.matcher(funName);
         if(matcher.matches())
         {
-            return new Callback(matcher.group(2), matcher.group(1));
+            return Pair.of(matcher.group(2), matcher.group(1));
         }
-        return new Callback(null, funName);
+        return Pair.of(null, funName);
     }
 
-    private ScheduledCall makeEventCall(CarpetContext cc, String function, List<Value> extraArgs, int argCount)
+    private ScheduledCall makeEventCall(CarpetContext cc, FunctionValue function, List<Value> extraArgs, int argCount)
     {
-        UserDefinedFunction udf = cc.host.globalFunctions.get(function);
+        if (function == null || (function.getArguments().size()-(extraArgs == null ? 0 : extraArgs.size())) != argCount)
-        if (udf == null || (udf.getArguments().size()-(extraArgs == null ? 0 : extraArgs.size())) != argCount)
         {
             // call won't match arguments
             return null;
@@ -503,19 +504,19 @@ public class CarpetEventServer
         return new ScheduledCall(cc, function, lazyArgs, 0);
     }
 
-    public ScheduledCall makeDeathCall(CarpetContext cc, String function, List<Value> extraArgs)
+    public ScheduledCall makeDeathCall(CarpetContext cc, FunctionValue function, List<Value> extraArgs)
     {
         return makeEventCall(cc, function, extraArgs, 2);
     }
-    public ScheduledCall makeRemovedCall(CarpetContext cc, String function, List<Value> extraArgs)
+    public ScheduledCall makeRemovedCall(CarpetContext cc, FunctionValue function, List<Value> extraArgs)
     {
         return makeEventCall(cc, function, extraArgs, 1);
     }
-    public ScheduledCall makeTickCall(CarpetContext cc, String function, List<Value> extraArgs)
+    public ScheduledCall makeTickCall(CarpetContext cc, FunctionValue function, List<Value> extraArgs)
     {
         return makeEventCall(cc, function, extraArgs, 1);
     }
-    public ScheduledCall makeDamageCall(CarpetContext cc, String function, List<Value> extraArgs)
+    public ScheduledCall makeDamageCall(CarpetContext cc, FunctionValue function, List<Value> extraArgs)
     {
         return makeEventCall(cc, function, extraArgs, 4);
     }

src/main/java/carpet/script/CarpetExpression.java

@@ -5,10 +5,12 @@ import carpet.fakes.MinecraftServerInterface;
 import carpet.helpers.FeatureGenerator;
 import carpet.script.Fluff.TriFunction;
 import carpet.script.exception.CarpetExpressionException;
+import carpet.script.exception.ExitStatement;
 import carpet.script.exception.ExpressionException;
 import carpet.script.exception.InternalExpressionException;
 import carpet.script.value.BlockValue;
 import carpet.script.value.EntityValue;
+import carpet.script.value.FunctionValue;
 import carpet.script.value.LazyListValue;
 import carpet.script.value.ListValue;
 import carpet.script.value.NBTSerializableValue;
@@ -2012,9 +2014,16 @@ public class CarpetExpression
                 throw new InternalExpressionException("First argument to entity_event should be an entity");
             String what = lv.get(1).evalValue(c).getString();
             Value functionValue = lv.get(2).evalValue(c);
-            String function = null;
+            if (functionValue instanceof NullValue)
-            if (!(functionValue instanceof NullValue))
+                functionValue = null;
-                function = functionValue.getString();
+            else if (!(functionValue instanceof FunctionValue))
+            {
+                String name = functionValue.getString();
+                functionValue = c.host.globalFunctions.get(name);
+                if (functionValue == null)
+                    throw new InternalExpressionException("Function "+name+" is not defined yet");
+            }
+            FunctionValue function = (FunctionValue)functionValue;
             List<Value> args = null;
             if (lv.size()==4)
                 args = Collections.singletonList(lv.get(3).evalValue(c));
@@ -2928,7 +2937,7 @@ public class CarpetExpression
             CarpetServer.scriptServer.tickStart = System.nanoTime(); // for the next tick
             Thread.yield();
             if(CarpetServer.scriptServer.stopAll)
-                throw new Expression.ExitStatement(Value.NULL);
+                throw new ExitStatement(Value.NULL);
             return (cc, tt) -> Value.TRUE;
         });
 
@@ -3002,20 +3011,28 @@ public class CarpetExpression
             if (lv.size()<2)
                 throw new InternalExpressionException("'schedule' should have at least 2 arguments, delay and call name");
             Long delay = NumericValue.asNumber(lv.get(0).evalValue(c)).getLong();
-            String funname = lv.get(1).evalValue(c).getString();
+
+            Value functionValue = lv.get(1).evalValue(c);
+            if (!(functionValue instanceof FunctionValue))
+            {
+                String name = functionValue.getString();
+                functionValue = c.host.globalFunctions.get(name);
+                if (functionValue == null)
+                    throw new InternalExpressionException("Function "+name+" is not defined yet");
+            }
+            FunctionValue function = (FunctionValue)functionValue;
+
             CarpetContext cc = (CarpetContext)c;
-            if (!cc.host.globalFunctions.containsKey(funname))
-                throw new InternalExpressionException("Function "+funname+" is not defined");
             List<LazyValue> args = new ArrayList<>();
             for (int i=2; i < lv.size(); i++)
             {
                 Value arg = lv.get(i).evalValue(cc);
                 args.add( (_c, _t) -> arg);
             }
-            if (cc.host.globalFunctions.get(funname).getArguments().size() != args.size())
+            if (function.getArguments().size() != args.size())
-                throw new InternalExpressionException("Function "+funname+" takes "+
+                throw new InternalExpressionException("Function "+function.getString()+" takes "+
-                        cc.host.globalFunctions.get(funname).getArguments().size()+" arguments, "+args.size()+" provided.");
+                        function.getArguments().size()+" arguments, "+args.size()+" provided.");
-            CarpetServer.scriptServer.events.scheduleCall(cc, funname, args, delay);
+            CarpetServer.scriptServer.events.scheduleCall(cc, function, args, delay);
             return (c_, t_) -> Value.TRUE;
         });
 

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

@@ -1,6 +1,7 @@
 package carpet.script;
 
 import carpet.script.bundled.BundledModule;
+import carpet.script.value.FunctionValue;
 import carpet.script.value.MapValue;
 import carpet.script.value.StringValue;
 import carpet.settings.CarpetSettings;
@@ -365,19 +366,19 @@ public class CarpetScriptServer
         return true;
     }
 
-    public boolean runas(ServerCommandSource source, String hostname, String udf_name, List<LazyValue> argv)
+    public boolean runas(ServerCommandSource source, String hostname, FunctionValue udf, List<LazyValue> argv)
     {
-        return runas(BlockPos.ORIGIN, source, hostname, udf_name, argv);
+        return runas(BlockPos.ORIGIN, source, hostname, udf, argv);
     }
 
-    public boolean runas(BlockPos origin, ServerCommandSource source, String hostname, String udf_name, List<LazyValue> argv)
+    public boolean runas(BlockPos origin, ServerCommandSource source, String hostname, FunctionValue udf, List<LazyValue> argv)
     {
         ScriptHost host = globalHost;
         try
         {
             if (hostname != null)
                 host = modules.get(hostname).retrieveForExecution(source);
-            host.callUDF(origin, source, host.globalFunctions.get(udf_name), argv);
+            host.callUDF(origin, source, udf, argv);
         }
         catch (NullPointerException | InvalidCallbackException npe)
         {

src/main/java/carpet/script/Context.java

@@ -37,7 +37,7 @@ public class Context
         return host.globalVariables.get(name);
     }
 
-    void setVariable(String name, LazyValue lv)
+    public void setVariable(String name, LazyValue lv)
     {
         if (name.startsWith("global_"))
         {

src/main/java/carpet/script/Expression.java

@@ -11,11 +11,15 @@ import carpet.script.Fluff.QuadFunction;
 import carpet.script.Fluff.QuinnFunction;
 import carpet.script.Fluff.SexFunction;
 import carpet.script.Fluff.TriFunction;
+import carpet.script.exception.ExitStatement;
 import carpet.script.exception.ExpressionException;
 import carpet.script.exception.InternalExpressionException;
+import carpet.script.exception.ReturnStatement;
+import carpet.script.exception.ThrowStatement;
 import carpet.script.value.AbstractListValue;
 import carpet.script.value.ContainerValueInterface;
 import carpet.script.value.FunctionSignatureValue;
+import carpet.script.value.FunctionValue;
 import carpet.script.value.GlobalValue;
 import carpet.script.value.LContainerValue;
 import carpet.script.value.LazyListValue;
@@ -389,31 +393,6 @@ public class Expression implements Cloneable
         return copy;
     }
 
-    /* Exception thrown to terminate execution mid expression (aka return statement) */
-    static class ExitStatement extends RuntimeException
-    {
-        Value retval;
-        ExitStatement(Value value)
-        {
-            retval = value;
-        }
-    }
-    static class ReturnStatement extends ExitStatement
-    {
-
-        ReturnStatement(Value value)
-        {
-            super(value);
-        }
-    }
-    static class ThrowStatement extends ExitStatement
-    {
-        ThrowStatement(Value value)
-        {
-            super(value);
-        }
-    }
-
 
     static List<String> getExpressionSnippet(Tokenizer.Token token, Expression expr)
     {
@@ -679,22 +658,11 @@ public class Expression implements Cloneable
             }
         });
     }
-    private void addContextFunction(Context context, String name, Expression expr, Tokenizer.Token token, List<String> arguments, List<String> globals, LazyValue code)
+    private FunctionValue addContextFunction(Context context, String name, Expression expr, Tokenizer.Token token, List<String> arguments, List<String> globals, LazyValue code)
     {
         name = name.toLowerCase(Locale.ROOT);
         if (functions.containsKey(name))
             throw new ExpressionException(expr, token, "Function "+name+" would mask a built-in function");
-        Expression function_context;
-        try
-        {
-            function_context = expr.clone();
-            function_context.name = name;
-        }
-        catch (CloneNotSupportedException e)
-        {
-            throw new ExpressionException(expr, token, "Problems in allocating global function "+name);
-        }
-
         Map<String, LazyValue> contextValues = new HashMap<>();
         for (String global : globals)
         {
@@ -708,67 +676,12 @@ public class Expression implements Cloneable
                 contextValues.put(global, lv);
             }
         }
+        if (contextValues.isEmpty()) contextValues = null;
 
-        context.host.globalFunctions.put(name, new UserDefinedFunction(arguments, function_context, token)
+        FunctionValue result =  new FunctionValue(expr, token, name, code, arguments, contextValues);
-        {
+        // do not store lambda definitions
-            @Override
+        if (!name.equals("_")) context.host.globalFunctions.put(name, result);
-            public LazyValue lazyEval(Context c, Integer type, Expression e, Tokenizer.Token t, List<LazyValue> lazyParams)
+        return result;
-            {
-                if (arguments.size() != lazyParams.size()) // something that might be subject to change in the future
-                {
-                    throw new ExpressionException(e, t,
-                            "Incorrect number of arguments for function "+name+
-                            ". Should be "+arguments.size()+", not "+lazyParams.size()+" like "+arguments
-                    );
-                }
-                Context newFrame = c.recreate();
-
-                contextValues.forEach(newFrame::setVariable);
-                for (int i=0; i<arguments.size(); i++)
-                {
-                    String arg = arguments.get(i);
-                    Value val = lazyParams.get(i).evalValue(c).reboundedTo(arg);
-                    newFrame.setVariable(arg, (cc, tt) -> val);
-                }
-                Value retVal;
-                boolean rethrow = false;
-                try
-                {
-                    retVal = code.evalValue(newFrame, type); // todo not sure if we need to propagete type / consider boolean context in defined functions - answer seems ye
-                }
-                catch (ReturnStatement returnStatement)
-                {
-                    retVal = returnStatement.retval;
-                }
-                catch (ThrowStatement throwStatement) // might not be really necessary
-                {
-                    retVal = throwStatement.retval;
-                    rethrow = true;
-                }
-                catch (InternalExpressionException exc)
-                {
-                    throw new ExpressionException(function_context, t, exc.getMessage());
-                }
-                catch (ArithmeticException exc)
-                {
-                    throw new ExpressionException(function_context, t, "Your math is wrong, "+exc.getMessage());
-                }
-                catch (ExitStatement | ExpressionException exit)
-                {
-                    throw exit;
-                }
-                catch (Exception exc)
-                {
-                    throw new ExpressionException(e, t, "Error while evaluating expression: "+exc.getMessage());
-                }
-                if (rethrow)
-                {
-                    throw new ThrowStatement(retVal);
-                }
-                Value otherRetVal = retVal;
-                return (cc, tt) -> otherRetVal;
-            }
-        });
     }
 
     /**
@@ -944,12 +857,15 @@ public class Expression implements Cloneable
         addLazyFunctionWithDelegation("call",-1, (c, t, expr, tok, lv) -> { // adjust based on c
             if (lv.size() == 0)
                 throw new InternalExpressionException("'call' expects at least function name to call");
-            String name = lv.get(0).evalValue(c).getString();
             //lv.remove(lv.size()-1); // aint gonna cut it // maybe it will because of the eager eval changes
             if (t != Context.SIGNATURE) // just call the function
             {
-                if (!c.host.globalFunctions.containsKey(name))
+                Value functionValue = lv.get(0).evalValue(c);
+                if (!(functionValue instanceof FunctionValue))
                 {
+                    String name = functionValue.getString();
+                    functionValue = c.host.globalFunctions.get(name);
+                    if (functionValue == null)
                         throw new InternalExpressionException("Function "+name+" is not defined yet");
                 }
                 List<LazyValue> lvargs = new ArrayList<>(lv.size()-1);
@@ -957,12 +873,12 @@ public class Expression implements Cloneable
                 {
                     lvargs.add(lv.get(i));
                 }
-                UserDefinedFunction acf = c.host.globalFunctions.get(name);
+                FunctionValue fun = (FunctionValue)functionValue;
-                Value retval = acf.lazyEval(c, t, acf.expression, acf.token, lvargs).evalValue(c);
+                Value retval = fun.callInContext(expr, c, t, fun.getExpression(), fun.getToken(), lvargs).evalValue(c);
                 return (cc, tt) -> retval; ///!!!! dono might need to store expr and token in statics? (e? t?)
             }
-
             // gimme signature
+            String name = lv.get(0).evalValue(c).getString();
             List<String> args = new ArrayList<>();
             List<String> globals = new ArrayList<>();
             for (int i = 1; i < lv.size(); i++)
@@ -981,8 +897,6 @@ public class Expression implements Cloneable
                     args.add(v.boundVariable);
                 }
             }
-            if (name.equals("_"))
-                name = "__lambda_"+tok.lineno+"_"+tok.linepos;
             Value retval = new FunctionSignatureValue(name, args, globals);
             return (cc, tt) -> retval;
         });
@@ -1003,20 +917,11 @@ public class Expression implements Cloneable
         addLazyBinaryOperatorWithDelegation("->", precedence.get("def->"), false, (c, type, e, t, lv1, lv2) ->
         {
             Value v1 = lv1.evalValue(c, Context.SIGNATURE);
-            String result;
+            if (!(v1 instanceof FunctionSignatureValue))
-            if (v1 instanceof FunctionSignatureValue)
+                throw new InternalExpressionException("'->' operator requires a function signature on the LHS");
-            {
             FunctionSignatureValue sign = (FunctionSignatureValue) v1;
-                addContextFunction(c, sign.getName(), e, t, sign.getArgs(), sign.getGlobals(), lv2);
+            Value result = addContextFunction(c, sign.getName(), e, t, sign.getArgs(), sign.getGlobals(), lv2);
-                result = sign.getName();
+            return (cc, tt) -> result;
-            }
-            else
-            {
-                v1.assertAssignable();
-                c.setVariable(v1.getVariable(), lv2);
-                result = v1.getVariable();
-            }
-            return (cc, tt) -> new StringValue(result);
         });
 
         addFunction("exit", (lv) -> { throw new ExitStatement(lv.size()==0?Value.NULL:lv.get(0)); });

src/main/java/carpet/script/ExpressionInspector.java

@@ -1,6 +1,6 @@
 package carpet.script;
 
-import carpet.CarpetServer;
+import carpet.script.exception.ExpressionException;
 import org.apache.commons.lang3.StringUtils;
 
 import java.util.Collections;
@@ -26,6 +26,20 @@ public class ExpressionInspector
         return e.getName();
     }
 
+    public static Expression Expression_cloneWithName(Expression e, String name, Tokenizer.Token token)
+    {
+        Expression copy = null;
+        try
+        {
+            copy = e.clone();
+        }
+        catch (CloneNotSupportedException ex)
+        {
+            throw new ExpressionException(e, token, "Problems in allocating global function "+name);
+        }
+        return copy.withName(name);
+    }
+
     private static TreeSet<String> scarpetFunctions;
     private static TreeSet<String> APIFunctions;
     static

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

@@ -2,6 +2,7 @@ package carpet.script;
 
 import carpet.CarpetServer;
 import carpet.script.bundled.ModuleInterface;
+import carpet.script.value.FunctionValue;
 import carpet.settings.CarpetSettings;
 import carpet.script.exception.ExpressionException;
 import carpet.script.exception.InvalidCallbackException;
@@ -20,7 +21,6 @@ import net.minecraft.util.math.BlockPos;
 
 import java.math.BigInteger;
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -31,7 +31,7 @@ import static java.lang.Math.max;
 public class ScriptHost
 {
     private final Map<String, ScriptHost> userHosts = new Object2ObjectOpenHashMap<>();
-    public Map<String, UserDefinedFunction> globalFunctions = new Object2ObjectOpenHashMap<>();
+    public Map<String, FunctionValue> globalFunctions = new Object2ObjectOpenHashMap<>();
     public Map<String, LazyValue> globalVariables = new Object2ObjectOpenHashMap<>();
 
     private Tag globalState;
@@ -118,8 +118,8 @@ public class ScriptHost
     {
         if (CarpetServer.scriptServer.stopAll)
             return "SCARPET PAUSED";
-        UserDefinedFunction acf = globalFunctions.get(call);
+        FunctionValue function = globalFunctions.get(call);
-        if (acf == null)
+        if (function == null)
             return "UNDEFINED";
         List<LazyValue> argv = new ArrayList<>();
         if (coords != null)
@@ -185,7 +185,7 @@ public class ScriptHost
                     return "Fail: "+tok.surface+" is not allowed in invoke";
             }
         }
-        List<String> args = acf.getArguments();
+        List<String> args = function.getArguments();
         if (argv.size() != args.size())
         {
             String error = "Fail: stored function "+call+" takes "+args.size()+" arguments, not "+argv.size()+ ":\n";
@@ -200,7 +200,7 @@ public class ScriptHost
             // TODO: this is just for now - invoke would be able to invoke other hosts scripts
             Context context = new CarpetContext(this, source, BlockPos.ORIGIN);
             return Expression.evalValue(
-                    () -> acf.lazyEval(context, Context.VOID, acf.expression, acf.token, argv),
+                    () -> function.lazyEval(context, Context.VOID, function.getExpression(), function.getToken(), argv),
                     context,
                     Context.VOID
             ).getString();
@@ -211,13 +211,11 @@ public class ScriptHost
         }
     }
 
-    public Value callUDF(BlockPos pos, ServerCommandSource source, UserDefinedFunction acf, List<LazyValue> argv) throws InvalidCallbackException
+    public Value callUDF(BlockPos pos, ServerCommandSource source, FunctionValue fun, List<LazyValue> argv) throws InvalidCallbackException
     {
         if (CarpetServer.scriptServer.stopAll)
             return Value.NULL;
-
+        if (argv.size() != fun.getArguments().size())
-        List<String> args = acf.getArguments();
-        if (argv.size() != args.size())
         {
             throw new InvalidCallbackException();
         }
@@ -226,7 +224,7 @@ public class ScriptHost
             // TODO: this is just for now - invoke would be able to invoke other hosts scripts
             Context context = new CarpetContext(this, source, pos);
             return Expression.evalValue(
-                    () -> acf.lazyEval(context, Context.VOID, acf.expression, acf.token, argv),
+                    () -> fun.lazyEval(context, Context.VOID, fun.getExpression(), fun.getToken(), argv),
                     context,
                     Context.VOID);
         }

src/main/java/carpet/script/UserDefinedFunction.java

@@ -1,29 +0,0 @@
-package carpet.script;
-
-import java.util.List;
-
-public abstract class UserDefinedFunction extends Fluff.AbstractLazyFunction implements Fluff.ILazyFunction
-{
-    protected List<String> arguments;
-    protected Expression expression;
-    protected Tokenizer.Token token;
-    UserDefinedFunction(List<String> args, Expression expr, Tokenizer.Token t)
-    {
-        super(args.size());
-        arguments = args;
-        expression = expr;
-        token = t;
-    }
-    public List<String> getArguments()
-    {
-        return arguments;
-    }
-    public Expression getExpression()
-    {
-        return expression;
-    }
-    public Tokenizer.Token getToken()
-    {
-        return token;
-    }
-}

src/main/java/carpet/script/exception/ExitStatement.java

@@ -0,0 +1,13 @@
+package carpet.script.exception;
+
+import carpet.script.value.Value;
+
+/* Exception thrown to terminate execution mid expression (aka return statement) */
+public class ExitStatement extends RuntimeException
+{
+    public Value retval;
+    public ExitStatement(Value value)
+    {
+        retval = value;
+    }
+}

src/main/java/carpet/script/exception/ReturnStatement.java

@@ -0,0 +1,12 @@
+package carpet.script.exception;
+
+import carpet.script.value.Value;
+
+public class ReturnStatement extends ExitStatement
+{
+
+    public ReturnStatement(Value value)
+    {
+        super(value);
+    }
+}

src/main/java/carpet/script/exception/ThrowStatement.java

@@ -0,0 +1,11 @@
+package carpet.script.exception;
+
+import carpet.script.value.Value;
+
+public class ThrowStatement extends ExitStatement
+{
+    public ThrowStatement(Value value)
+    {
+        super(value);
+    }
+}

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

@@ -775,14 +775,14 @@ public class EntityValue extends Value
         // "nbt" <-big one, for now use run('data merge entity ...
     }};
 
-    public void setEvent(CarpetContext cc, String event, String fun, List<Value> args)
+    public void setEvent(CarpetContext cc, String event, FunctionValue fun, List<Value> args)
     {
         if (!(events.containsKey(event)))
             throw new InternalExpressionException("Unknown entity event: " + event);
         events.get(event).accept(cc, entity, fun, args);
     }
 
-    private static Map<String, Fluff.QuadConsumer<CarpetContext, Entity, String, List<Value>>> events = new HashMap<String, Fluff.QuadConsumer<CarpetContext, Entity, String, List<Value>>>() {{
+    private static Map<String, Fluff.QuadConsumer<CarpetContext, Entity, FunctionValue, List<Value>>> events = new HashMap<String, Fluff.QuadConsumer<CarpetContext, Entity, FunctionValue, List<Value>>>() {{
         put("on_death", (c, e, f, l) -> ((EntityInterface)e).setDeathCallback(c, f, l));
         put("on_removed", (c, e, f, l) -> ((EntityInterface)e).setRemovedCallback(c, f, l));
         put("on_tick", (c, e, f, l) -> ((EntityInterface)e).setTickCallback(c, f, l));

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

@@ -1,7 +1,5 @@
 package carpet.script.value;
 
-import carpet.script.exception.ExpressionException;
-
 import java.util.List;
 
 public class FunctionSignatureValue extends FrameworkValue
@@ -10,7 +8,6 @@ public class FunctionSignatureValue extends FrameworkValue
     private List<String> arguments;
     private List<String> globals;
 
-
     public FunctionSignatureValue(String name, List<String> args, List<String> globals)
     {
         this.identifier = name;

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

@@ -0,0 +1,204 @@
+package carpet.script.value;
+
+import carpet.script.Context;
+import carpet.script.Expression;
+import carpet.script.ExpressionInspector;
+import carpet.script.Fluff;
+import carpet.script.LazyValue;
+import carpet.script.Tokenizer;
+import carpet.script.exception.ExitStatement;
+import carpet.script.exception.ExpressionException;
+import carpet.script.exception.InternalExpressionException;
+import carpet.script.exception.ReturnStatement;
+import carpet.script.exception.ThrowStatement;
+
+import java.util.List;
+import java.util.Map;
+
+public class FunctionValue extends Value implements Fluff.ILazyFunction
+{
+    private Expression expression;
+    private Tokenizer.Token token;
+    private String name;
+    private LazyValue body;
+    private Map<String, LazyValue> outerState;
+    private List<String> args;
+    private static long variantCounter = 1;
+    private long variant;
+
+    public FunctionValue(Expression expression, Tokenizer.Token token, String name, LazyValue body, List<String> args)
+    {
+        this.expression = expression;
+        this.token = token;
+        this.name = name;
+        this.body = body;
+        this.args = args;
+        this.outerState = null;
+        variant = 0L;
+    }
+
+    public FunctionValue(Expression expression, Tokenizer.Token token, String name, LazyValue body, List<String> args, Map<String, LazyValue> outerState)
+    {
+        this.expression = expression;
+        this.token = token;
+        this.name = name;
+        this.body = body;
+        this.args = args;
+        this.outerState = outerState;
+        variant = variantCounter++;
+    }
+
+    @Override
+    public String getString()
+    {
+        return name;
+    }
+
+    @Override
+    public boolean getBoolean()
+    {
+        return true;
+    }
+
+    @Override
+    protected Value clone()
+    {
+        FunctionValue ret = new FunctionValue(expression, token, name, body, args);
+        ret.outerState = this.outerState;
+        ret.variant = this.variant;
+        return ret;
+    }
+
+    @Override
+    public int hashCode()
+    {
+        return name.hashCode()+(int)variant;
+    }
+
+    @Override
+    public boolean equals(Object o)
+    {
+        if (o instanceof FunctionValue)
+            return name.equals(((FunctionValue) o).name) && variant == ((FunctionValue) o).variant;
+        return false;
+    }
+
+    @Override
+    public int compareTo(final Value o)
+    {
+        if (o instanceof FunctionValue)
+        {
+            int nameSame = this.name.compareTo(((FunctionValue) o).name);
+            if (nameSame != 0)
+                return nameSame;
+            return (int) (variant-((FunctionValue) o).variant);
+        }
+        return getString().compareTo(o.getString());
+    }
+
+    @Override
+    public double readNumber()
+    {
+        throw new InternalExpressionException("Function value has no numeric value");
+    }
+
+    @Override
+    public Value slice(long from, long to)
+    {
+        throw new InternalExpressionException("Cannot slice a function");
+    }
+
+    @Override
+    public int getNumParams()
+    {
+        return args.size();
+    }
+
+    @Override
+    public boolean numParamsVaries()
+    {
+        return false;
+    }
+
+    public LazyValue callInContext(Expression callingExpression, Context c, Integer type, Expression e, Tokenizer.Token t, List<LazyValue> lazyParams)
+    {
+        // this hole thing might not be really needed
+        Expression callContext = ExpressionInspector.Expression_cloneWithName(callingExpression, name, t);
+        try
+        {
+            return lazyEval(c, type, e, t, lazyParams);
+        }
+        catch (InternalExpressionException exc)
+        {
+            throw new ExpressionException(callContext, t, exc.getMessage());
+        }
+        catch (ArithmeticException exc)
+        {
+            throw new ExpressionException(callContext, t, "Your math is wrong, "+exc.getMessage());
+        }
+    }
+
+    @Override
+    public LazyValue lazyEval(Context c, Integer type, Expression e, Tokenizer.Token t, List<LazyValue> lazyParams)
+    {
+        if (args.size() != lazyParams.size()) // something that might be subject to change in the future
+                                              // in case we add variable arguments
+        {
+            throw new ExpressionException(e, t,
+                    "Incorrect number of arguments for function "+name+
+                            ". Should be "+args.size()+", not "+lazyParams.size()+" like "+args
+            );
+        }
+        Context newFrame = c.recreate();
+
+        if (outerState != null) outerState.forEach(newFrame::setVariable);
+        for (int i=0; i<args.size(); i++)
+        {
+            String arg = args.get(i);
+            Value val = lazyParams.get(i).evalValue(c).reboundedTo(arg);
+            newFrame.setVariable(arg, (cc, tt) -> val);
+        }
+        Value retVal;
+        boolean rethrow = false;
+        try
+        {
+            retVal = body.evalValue(newFrame, type); // todo not sure if we need to propagete type / consider boolean context in defined functions - answer seems ye
+        }
+        catch (ReturnStatement returnStatement)
+        {
+            retVal = returnStatement.retval;
+        }
+        catch (ThrowStatement throwStatement) // might not be really necessary
+        {
+            retVal = throwStatement.retval;
+            rethrow = true;
+        }
+        catch (ArithmeticException | ExitStatement | ExpressionException exc)
+        {
+            throw exc; // rethrow so could be contextualized if needed
+        }
+        catch (Exception exc)
+        {
+            throw new ExpressionException(e, t, "Error while evaluating expression: "+exc.getMessage());
+        }
+        if (rethrow)
+        {
+            throw new ThrowStatement(retVal);
+        }
+        Value otherRetVal = retVal;
+        return (cc, tt) -> otherRetVal;
+    }
+
+    public Expression getExpression()
+    {
+        return expression;
+    }
+    public Tokenizer.Token getToken()
+    {
+        return token;
+    }
+    public List<String> getArguments()
+    {
+        return args;
+    }
+}

src/main/java/carpet/settings/SettingsManager.java

@@ -3,6 +3,7 @@ package carpet.settings;
 import carpet.CarpetServer;
 import carpet.utils.Messenger;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Sets;
 import com.mojang.brigadier.CommandDispatcher;
 import com.mojang.brigadier.arguments.StringArgumentType;
 import com.mojang.brigadier.builder.LiteralArgumentBuilder;
@@ -264,8 +265,10 @@ public class SettingsManager
         String lcSearch = search.toLowerCase(Locale.ROOT);
         return rules.values().stream().filter(rule ->
         {
-            if (rule.name.toLowerCase(Locale.ROOT).contains(lcSearch)) return true;
+            if (rule.name.toLowerCase(Locale.ROOT).contains(lcSearch)) return true; // substring match, case insensitive
-            for (String c : rule.categories) if (c.toLowerCase(Locale.ROOT).equals(search)) return true;
+            for (String c : rule.categories) if (c.equals(search)) return true; // category exactly, case sensitive
+            if (Sets.newHashSet(rule.description.toLowerCase(Locale.ROOT).split("\\W+")).contains(lcSearch))
+                return true; // contains full term in description, but case insensitive
             return false;
         }).collect(ImmutableList.toImmutableList());
     }