Add alloc command

rforth.py

@@ -1,7 +1,7 @@
 #!/usr/bin/python3
 import argparse
 stack = []
-heap = [0] * 10
+heap = [0] * 20
 next_heap = 0
 compiling = False
 words = {}
@@ -64,6 +64,8 @@ def parse_input(input_string, say_ok=True):
                 fetch()
             elif string == "heap":
                 dump_heap()
+            elif string == "alloc":
+                alloc()
         else:
             if string == ";":
                 stop_compiling()
@@ -76,6 +78,12 @@ def parse_input(input_string, say_ok=True):
 def dump_heap():
     print(heap)
 
+def alloc():
+    global next_heap
+    heap[next_heap] = 0
+    stack.insert(0, next_heap)
+    next_heap += 1
+
 def store():
     k = stack.pop(0)
     v = stack.pop(0)