added reset_seed

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

@@ -313,6 +313,11 @@ public class Expression
         addUnaryFunction(name, (v) -> new NumericValue(fun.apply(NumericValue.asNumber(v).getDouble())));
     }
 
+    public void addMathematicalUnaryIntFunction(String name, Function<Double, Long> fun)
+    {
+        addUnaryFunction(name, (v) -> new NumericValue(fun.apply(NumericValue.asNumber(v).getDouble())));
+    }
+
     public void addMathematicalBinaryFunction(String name, BiFunction<Double, Double, Double> fun)
     {
         addBinaryFunction(name, (w, v) ->

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

@@ -42,6 +42,10 @@ public abstract class ScriptHost
         return randomizers.computeIfAbsent(aLong, Random::new);
     }
 
+    public boolean resetRandom(long aLong) {
+        return randomizers.remove(aLong) != null;
+    }
+
     public static class ModuleData
     {
         Module parent;

src/main/java/carpet/script/language/Sys.java

@@ -210,6 +210,10 @@ public class Sys {
             Value retval = new NumericValue(NumericValue.asNumber(argument).getDouble()*randomizer.nextDouble());
             return (cc, tt) -> retval;
         });
+        expression.addLazyFunction("reset_seed", 1, (c, t, lv) -> {
+            boolean gotIt = c.host.resetRandom(NumericValue.asNumber(lv.get(0).evalValue(c)).getLong());
+            return gotIt?LazyValue.TRUE:LazyValue.FALSE;
+        });
 
         expression.addLazyFunction("perlin", -1, (c, t, lv) ->
         {