list tweaks

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

@@ -1977,9 +1977,7 @@ public class CarpetExpression
                 int y;
                 int z;
                 {
-                    x = minx;
-                    y = miny;
-                    z = minz;
+                    reset();
                 }
                 @Override
                 public boolean hasNext()
@@ -2012,6 +2010,15 @@ public class CarpetExpression
                 public void fatality()
                 {
                     // possibly return original x, y, z
+                    super.fatality();
+                }
+
+                @Override
+                public void reset()
+                {
+                    x = minx;
+                    y = miny;
+                    z = minz;
                 }
             };
         });
@@ -2066,10 +2073,10 @@ public class CarpetExpression
             {
                 return (c_, t_) -> new LazyListValue()
                 {
-                    int curradius = 0;
-                    int curpos = 0;
+                    int curradius;
+                    int curpos;
                     {
-
+                        reset();
                     }
                     @Override
                     public boolean hasNext()
@@ -2097,15 +2104,25 @@ public class CarpetExpression
                         return block;
 
                     }
+
+                    @Override
+                    public void reset()
+                    {
+                        curradius = 0;
+                        curpos = 0;
+                    }
                 };
             }
             else
             {
                 return (c_, t_) -> new LazyListValue()
                 {
-                    int curradius = 0;
-                    int curpos = 0;
-                    int curheight = -height;
+                    int curradius;
+                    int curpos;
+                    int curheight;
+                    {
+                        reset();
+                    }
                     @Override
                     public boolean hasNext()
                     {
@@ -2142,6 +2159,14 @@ public class CarpetExpression
                         }
                         return block;
                     }
+
+                    @Override
+                    public void reset()
+                    {
+                        curradius = 0;
+                        curpos = 0;
+                        curheight = -height;
+                    }
                 };
             }
         });

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

@@ -12,6 +12,7 @@ import carpet.script.Fluff.SexFunction;
 import carpet.script.Fluff.TriFunction;
 import carpet.script.exception.ExpressionException;
 import carpet.script.exception.InternalExpressionException;
+import carpet.script.value.AbstractListValue;
 import carpet.script.value.FunctionSignatureValue;
 import carpet.script.value.GlobalValue;
 import carpet.script.value.LazyListValue;
@@ -1857,12 +1858,12 @@ public class Expression implements Cloneable
             return LazyListValue.range(from, to, step);
         });
 
-        addBinaryFunction("get", (v1, v2) -> v1.getElementAt(v2));
+        addBinaryFunction("get", Value::getElementAt);
 
         //Deprecated, use "get" instead
         addBinaryFunction("element", (v1, v2) ->
         {
-            if (v1 instanceof LazyListValue || !(v1 instanceof ListValue))
+            if (!(v1 instanceof ListValue))
                 throw new InternalExpressionException("First argument of get should be a list");
             List<Value> items = ((ListValue)v1).getItems();
             long index = NumericValue.asNumber(v2).getLong();
@@ -1880,7 +1881,7 @@ public class Expression implements Cloneable
                 throw new InternalExpressionException("put takes at least three arguments, a list, index, and values to insert at that index");
             }
             Value list = lv.get(0);
-            if (list instanceof LazyListValue || !(list instanceof ListValue))
+            if (!(list instanceof ListValue))
             {
                 throw new InternalExpressionException("First argument of element should be a list");
             }
@@ -1965,9 +1966,9 @@ public class Expression implements Cloneable
 
             Value rval= lv.get(0).evalValue(c);
 
-            if (!(rval instanceof ListValue))
+            if (!(rval instanceof AbstractListValue))
                 throw new InternalExpressionException("First argument of map function should be a list or iterator");
-            Iterator<Value> iterator = ((ListValue) rval).iterator();
+            Iterator<Value> iterator = ((AbstractListValue) rval).iterator();
             LazyValue expr = lv.get(1);
             LazyValue cond = null;
             if(lv.size() > 2) cond = lv.get(2);
@@ -1991,12 +1992,12 @@ public class Expression implements Cloneable
                 }
                 next.boundVariable = var;
             }
-            ((ListValue) rval).fatality();
-            LazyValue ret = (cc, tt) -> ListValue.wrap(result);
+            ((AbstractListValue) rval).fatality();
+            Value ret = ListValue.wrap(result);
             //revering scope
             c.setVariable("_", _val);
             c.setVariable("_i", _iter);
-            return ret;
+            return (cc, tt) ->  ret;
         });
 
         // grep(list or num, expr, exit_expr) => list
@@ -2010,9 +2011,9 @@ public class Expression implements Cloneable
             }
 
             Value rval= lv.get(0).evalValue(c);
-            if (!(rval instanceof ListValue))
+            if (!(rval instanceof AbstractListValue))
                 throw new InternalExpressionException("First argument of filter function should be a list or iterator");
-            Iterator<Value> iterator = ((ListValue) rval).iterator();
+            Iterator<Value> iterator = ((AbstractListValue) rval).iterator();
             LazyValue expr = lv.get(1);
             LazyValue cond = null;
             if(lv.size() > 2) cond = lv.get(2);
@@ -2037,12 +2038,12 @@ public class Expression implements Cloneable
                 }
                 next.boundVariable = var;
             }
-            ((ListValue) rval).fatality();
-            LazyValue ret = (cc, tt) -> ListValue.wrap(result); // might be a trap - lazy evaluation
+            ((AbstractListValue) rval).fatality();
+            Value ret = ListValue.wrap(result);
             //revering scope
             c.setVariable("_", _val);
             c.setVariable("_i", _iter);
-            return ret;
+            return (cc, tt) -> ret;
         });
 
         // first(list, expr) => elem or null
@@ -2052,9 +2053,9 @@ public class Expression implements Cloneable
         {
 
             Value rval= lv.get(0).evalValue(c);
-            if (!(rval instanceof ListValue))
+            if (!(rval instanceof AbstractListValue))
                 throw new InternalExpressionException("First argument of 'first' function should be a list or iterator");
-            Iterator<Value> iterator = ((ListValue) rval).iterator();
+            Iterator<Value> iterator = ((AbstractListValue) rval).iterator();
             LazyValue expr = lv.get(1);
             //scoping
             LazyValue _val = c.getVariable("_");
@@ -2077,7 +2078,7 @@ public class Expression implements Cloneable
                 next.boundVariable = var;
             }
             //revering scope
-            ((ListValue) rval).fatality();
+            ((AbstractListValue) rval).fatality();
             Value whyWontYouTrustMeJava = result;
             c.setVariable("_", _val);
             c.setVariable("_i", _iter);
@@ -2090,9 +2091,9 @@ public class Expression implements Cloneable
         addLazyFunction("all", 2, (c, t, lv) ->
         {
             Value rval= lv.get(0).evalValue(c);
-            if (!(rval instanceof ListValue))
+            if (!(rval instanceof AbstractListValue))
                 throw new InternalExpressionException("First argument of 'all' function should be a list or iterator");
-            Iterator<Value> iterator = ((ListValue) rval).iterator();
+            Iterator<Value> iterator = ((AbstractListValue) rval).iterator();
             LazyValue expr = lv.get(1);
             //scoping
             LazyValue _val = c.getVariable("_");
@@ -2115,7 +2116,7 @@ public class Expression implements Cloneable
                 next.boundVariable = var;
             }
             //revering scope
-            ((ListValue) rval).fatality();
+            ((AbstractListValue) rval).fatality();
             c.setVariable("_", _val);
             c.setVariable("_i", _iter);
             return result;
@@ -2131,9 +2132,9 @@ public class Expression implements Cloneable
                 throw new InternalExpressionException("Incorrect number of attributes for 'for', should be 2 or 3, not "+lv.size());
             }
             Value rval= lv.get(0).evalValue(c);
-            if (!(rval instanceof ListValue))
+            if (!(rval instanceof AbstractListValue))
                 throw new InternalExpressionException("Second argument of 'for' function should be a list or iterator");
-            Iterator<Value> iterator = ((ListValue) rval).iterator();
+            Iterator<Value> iterator = ((AbstractListValue) rval).iterator();
             LazyValue expr = lv.get(1);
             LazyValue cond = null;
             if(lv.size() > 2) cond = lv.get(2);
@@ -2160,7 +2161,7 @@ public class Expression implements Cloneable
                 next.boundVariable = var;
             }
             //revering scope
-            ((ListValue) rval).fatality();
+            ((AbstractListValue) rval).fatality();
             c.setVariable("_", _val);
             c.setVariable("_i", _iter);
             long promiseWontChange = successCount;
@@ -2178,9 +2179,9 @@ public class Expression implements Cloneable
 
             Value acc = lv.get(2).evalValue(c);
             Value rval= lv.get(0).evalValue(c);
-            if (!(rval instanceof ListValue))
+            if (!(rval instanceof AbstractListValue))
                 throw new InternalExpressionException("First argument of 'reduce' should be a list or iterator");
-            Iterator<Value> iterator = ((ListValue) rval).iterator();
+            Iterator<Value> iterator = ((AbstractListValue) rval).iterator();
 
             if (!iterator.hasNext())
             {
@@ -2204,7 +2205,7 @@ public class Expression implements Cloneable
                 next.boundVariable = var;
             }
             //reverting scope
-            ((ListValue) rval).fatality();
+            ((AbstractListValue) rval).fatality();
             c.setVariable("_a", _acc);
             c.setVariable("_", _val);
 

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

@@ -0,0 +1,21 @@
+package carpet.script.value;
+
+import carpet.script.exception.InternalExpressionException;
+import net.minecraft.item.ItemStack;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.util.registry.Registry;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static java.lang.Math.abs;
+
+public abstract class AbstractListValue extends Value
+{
+    public abstract Iterator<Value> iterator();
+    public void fatality() { }
+}

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

@@ -1,7 +1,6 @@
 package carpet.script.value;
 
 import carpet.script.exception.ExpressionException;
-import carpet.script.exception.InternalExpressionException;
 
 import java.util.List;
 
@@ -23,12 +22,6 @@ public class FunctionSignatureValue extends Value
         throw new ExpressionException("Function "+identifier+" is not defined yet");
     }
 
-    @Override
-    public String getTypeString()
-    {
-        throw new InternalExpressionException("How did you get here? Cannot get type of an internal struct.");
-    }
-
     @Override
     public Value clone()
     {

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

@@ -1,7 +1,5 @@
 package carpet.script.value;
 
-import carpet.script.exception.InternalExpressionException;
-
 public class GlobalValue extends Value
 {
     public GlobalValue(Value variable)
@@ -21,10 +19,4 @@ public class GlobalValue extends Value
     {
         return false;
     }
-
-    @Override
-    public String getTypeString()
-    {
-        throw new InternalExpressionException("How did you get here? Cannot get type of an internal struct.");
-    }
 }

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

@@ -7,7 +7,7 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 
-public abstract class LazyListValue extends ListValue implements Iterator<Value>
+public abstract class LazyListValue extends AbstractListValue implements Iterator<Value>
 {
     public static LazyListValue range(long from, long to, long step)
     {
@@ -16,10 +16,12 @@ public abstract class LazyListValue extends ListValue implements Iterator<Value>
             {
                 if (step == 0)
                     throw new InternalExpressionException("range will never end with zero step");
-                this.current = from;
+                this.start = from;
+                this.current = this.start;
                 this.limit = to;
                 this.stepp = step;
             }
+            private long start;
             private long current;
             private long limit;
             private long stepp;
@@ -31,6 +33,12 @@ public abstract class LazyListValue extends ListValue implements Iterator<Value>
                 return val;
             }
 
+            @Override
+            public void reset()
+            {
+                current = start;
+            }
+
             @Override
             public boolean hasNext()
             {
@@ -39,11 +47,6 @@ public abstract class LazyListValue extends ListValue implements Iterator<Value>
         };
     }
 
-    public LazyListValue()
-    {
-        super(Collections.emptyList());
-    }
-
     @Override
     public String getString()
     {
@@ -59,6 +62,10 @@ public abstract class LazyListValue extends ListValue implements Iterator<Value>
 
     public abstract Value next();
 
+    @Override
+    public void fatality() {reset();}
+    public abstract void reset();
+
     @Override
     public Iterator<Value> iterator() {return this;}
 
@@ -66,6 +73,7 @@ public abstract class LazyListValue extends ListValue implements Iterator<Value>
     {
         List<Value> result = new ArrayList<>();
         this.forEachRemaining(result::add);
+        fatality();
         return result;
     }
 
@@ -83,14 +91,20 @@ public abstract class LazyListValue extends ListValue implements Iterator<Value>
             if (hasNext())
                 next();
             else
+            {
+                fatality();
                 return ListValue.wrap(result);
+            }
         }
         for (i = (int)from; i < to; i++)
         {
             if (hasNext())
                 result.add(next());
             else
+            {
+                fatality();
                 return ListValue.wrap(result);
+            }
         }
         return ListValue.wrap(result);
     }
@@ -116,5 +130,19 @@ public abstract class LazyListValue extends ListValue implements Iterator<Value>
     {
         return "iterator";
     }
-
+    @Override
+    public Object clone()
+    {
+        Object copy;
+        try
+        {
+            copy = super.clone();
+        }
+        catch (CloneNotSupportedException e)
+        {
+            throw new InternalExpressionException("cannot copy iterator");
+        }
+        ((LazyListValue)copy).reset();
+        return copy;
+    }
 }

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

@@ -2,7 +2,6 @@ package carpet.script.value;
 
 import carpet.script.exception.InternalExpressionException;
 import net.minecraft.item.ItemStack;
-import net.minecraft.nbt.CompoundTag;
 import net.minecraft.util.registry.Registry;
 
 import java.util.ArrayList;
@@ -14,7 +13,7 @@ import java.util.stream.Collectors;
 
 import static java.lang.Math.abs;
 
-public class ListValue extends Value
+public class ListValue extends AbstractListValue
 {
     protected List<Value> items;
     @Override
@@ -241,9 +240,6 @@ public class ListValue extends Value
     {
         return items.iterator();
     }
-    public void fatality()
-    {
-    }
 
     public void extend(List<Value> subList)
     {
@@ -331,7 +327,4 @@ public class ListValue extends Value
     {
         return "list";
     }
-
-
-
 }

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

@@ -178,5 +178,8 @@ public abstract class Value implements Comparable<Value>, Cloneable
         throw new InternalExpressionException("get element can only be obtained for lists and nbt values");
     }
 
-    public abstract String getTypeString();
+    public String getTypeString()
+    {
+        throw new InternalExpressionException("How did you get here? Cannot get type of an intenal type.");
+    }
 }