add Column#forRanges

common/api/src/main/java/com/dfsek/terra/api/util/Column.java

@@ -1,5 +1,6 @@
 package com.dfsek.terra.api.util;
 
+import com.dfsek.terra.api.util.function.IntIntObjConsumer;
 import com.dfsek.terra.api.util.function.IntObjConsumer;
 
 import com.google.common.collect.ImmutableList;
@@ -28,6 +29,22 @@ public interface Column<T> {
         }
     }
     
+    default void forRanges(IntIntObjConsumer<T> consumer) {
+        int y = getMinY();
+        int runningMin = y;
+        T runningObj = get(runningMin);
+        do {
+            y++;
+            T current = get(y);
+            
+            if(!current.equals(runningObj)) {
+                consumer.accept(runningMin, y, runningObj);
+                runningMin = y;
+                runningObj = current;
+            }
+        } while(y < getMaxY());
+    }
+    
     default List<? extends T> asList() {
         List<T> list = new ArrayList<>();
         forEach((Consumer<T>) list::add);

common/api/src/main/java/com/dfsek/terra/api/util/function/IntIntObjConsumer.java

@@ -0,0 +1,6 @@
+package com.dfsek.terra.api.util.function;
+
+@FunctionalInterface
+public interface IntIntObjConsumer<T> {
+    void accept(int i, int j, T obj);
+}