Initial data commit

Task/Stack/BBC-BASIC/stack.basic

@@ -0,0 +1,31 @@
+      STACKSIZE = 1000
+
+      FOR n = 3 TO 5
+        PRINT "Push ";n : PROCpush(n)
+      NEXT
+      PRINT "Pop " ; FNpop
+      PRINT "Push 6" : PROCpush(6)
+      REPEAT
+        PRINT "Pop " ; FNpop
+      UNTIL FNisempty
+      PRINT "Pop " ; FNpop
+      END
+
+      DEF PROCpush(n) : LOCAL f%
+      DEF FNpop : LOCAL f% : f% = 1
+      DEF FNisempty : LOCAL f% : f% = 2
+      PRIVATE stack(), sptr%
+      DIM stack(STACKSIZE-1)
+      CASE f% OF
+        WHEN 0:
+          IF sptr% = DIM(stack(),1) ERROR 100, "Error: stack overflowed"
+          stack(sptr%) = n
+          sptr% += 1
+        WHEN 1:
+          IF sptr% = 0 ERROR 101, "Error: stack empty"
+          sptr% -= 1
+          = stack(sptr%)
+        WHEN 2:
+          = (sptr% = 0)
+      ENDCASE
+      ENDPROC