negative steps supported

stdlib/src/jet/ByteRange.java

@@ -37,6 +37,9 @@ public final class ByteRange implements Range<Byte>, ByteIterable, JetObject {
     }
 
     public ByteIterator step(int step) {
+        if(step < 0)
+            return new MyIterator(getEnd(), -count, -step);
+        else
             return new MyIterator(start, count, step);
     }
 

stdlib/src/jet/CharRange.java

@@ -41,6 +41,9 @@ public final class CharRange implements Range<Character>, CharIterable, JetObjec
     }
 
     public CharIterator step(int step) {
+        if(step < 0)
+            return new MyIterator(getEnd(), -count, -step);
+        else
             return new MyIterator(start, count, step);
     }
 

stdlib/src/jet/IntRange.java

@@ -21,6 +21,9 @@ public final class IntRange implements Range<Integer>, IntIterable, JetObject {
     }
 
     public IntIterator step(int step) {
+        if(step < 0)
+            return new MyIterator(getEnd(), -count, -step);
+        else
             return new MyIterator(start, count, step);
     }
 

stdlib/src/jet/LongRange.java

@@ -12,6 +12,9 @@ public final class LongRange implements Range<Long>, LongIterable, JetObject {
     }
 
     public LongIterator step(long step) {
+        if(step < 0)
+            return new MyIterator(getEnd(), -count, -step);
+        else
             return new MyIterator(start, count, step);
     }
 

stdlib/src/jet/ShortRange.java

@@ -12,6 +12,9 @@ public final class ShortRange implements Range<Short>, ShortIterable, JetObject
     }
 
     public ShortIterator step(int step) {
+        if(step < 0)
+            return new MyIterator(getEnd(), -count, -step);
+        else
             return new MyIterator(start, count, step);
     }