Добавлена функция functional::dropwhile

Author: aNNiMON

src/main/java/com/annimon/ownlang/lib/modules/functional.java

@@ -25,6 +25,7 @@ public void init() {
         Functions.set("filter", new functional_filter(false));
         Functions.set("sortby", new functional_sortby());
         Functions.set("takewhile", new functional_filter(true));
+        Functions.set("dropwhile", new functional_dropwhile());
 
         Functions.set("chain", new functional_chain());
         Functions.set("combine", new functional_combine());

src/main/java/com/annimon/ownlang/lib/modules/functions/functional_dropwhile.java

@@ -2,52 +2,35 @@
 
 import com.annimon.ownlang.exceptions.TypeException;
 import com.annimon.ownlang.lib.*;
-import java.util.ArrayList;
-import java.util.List;
 
-import java.util.Map;
-
-public final class functional_filter implements Function {
+public final class functional_dropwhile implements Function {
 
     @Override
     public Value execute(Value... args) {
         Arguments.check(2, args.length);
+        if (args[0].type() != Types.ARRAY) {
+            throw new TypeException("Array expected in first argument");
+        }
         if (args[1].type() != Types.FUNCTION) {
             throw new TypeException("Function expected in second argument");
         }
 
         final Value container = args[0];
-        final Function consumer = ((FunctionValue) args[1]).getValue();
-        if (container.type() == Types.ARRAY) {
-            return filterArray((ArrayValue) container, consumer);
-        }
-        
-        if (container.type() == Types.MAP) {
-            return filterMap((MapValue) container, consumer);
-        }
-
-        throw new TypeException("Invalid first argument. Array or map expected");
+        final Function predicate = ((FunctionValue) args[1]).getValue();
+        return dropWhileArray((ArrayValue) container, predicate);
     }
 
-    private Value filterArray(ArrayValue array, Function predicate) {
-        final int size = array.size();
-        final List<Value> values = new ArrayList<Value>(size);
+    private Value dropWhileArray(ArrayValue array, Function predicate) {
+        int skipCount = 0;
         for (Value value : array) {
-            if (predicate.execute(value) != NumberValue.ZERO) {
-                values.add(value);
-            }
+            if (predicate.execute(value) != NumberValue.ZERO)
+                skipCount++;
+            else break;
         }
-        final int newSize = values.size();
-        return new ArrayValue(values.toArray(new Value[newSize]));
-    }
-    
-    private Value filterMap(MapValue map, Function predicate) {
-        final MapValue result = new MapValue(map.size());
-        for (Map.Entry<Value, Value> element : map) {
-            if (predicate.execute(element.getKey(), element.getValue()) != NumberValue.ZERO) {
-                result.set(element.getKey(), element.getValue());
-            }
-        }
-        return result;
+
+        final int size = array.size();
+        final Value[] result = new Value[size - skipCount];
+        System.arraycopy(array.getCopyElements(), skipCount, result, 0, result.length);
+        return new ArrayValue(result);
     }
 }