Author: jquelin
Date: Fri Jan 9 01:06:36 2009
New Revision: 35249
Modified:
trunk/languages/befunge/stack.pir
Log:
new sub stack__pop()
Modified: trunk/languages/befunge/stack.pir
==============================================================================
--- trunk/languages/befunge/stack.pir (original)
+++ trunk/languages/befunge/stack.pir Fri Jan 9 01:06:36 2009
@@ -1,25 +1,53 @@
# $Id$
-=pod
-
-# Duplicate.
-# Befunge stack:
+#
+# stack_duplicate()
+#
+# duplicate element at top of stck
+# befunge stack:
# before: ... v
-# after: ... v
-STACK_DUP:
- set I10, P2
- unless I10, STACK_DUP_POP_1
- pop I10, P2
-STACK_DUP_POP_1:
- push P2, I10
- push P2, I10
- branch MOVE_PC
-
-# Pop.
-# Befunge stack:
+# after: ... v v
+# no return value
+#
+.sub "stack__duplicate"
+ $P0 = get_global "stack"
+
+ $I0 = $P0
+ if $I0 == 0 goto STACK__DUPLICATE_END
+
+ $I1 = pop $P0
+ push $P0, $I1
+ push $P0, $I1
+ set_global "stack", $P0
+
+ STACK__DUPLICATE_END:
+ .return()
+.end
+
+
+#
+# val = stack__pop()
+#
+# pop and return a value from the stack, or 0 if stack is empty.
+# befunge stack:
# before: ... v
# after: ...
-# Element is just discarded.
+#
+.sub "stack__pop"
+ $P0 = get_global "stack"
+
+ $I0 = $P0
+ if $I0 > 0 goto STACK__POP__POP
+ .return(0)
+
+ STACK__POP__POP:
+ $I1 = pop $P0
+ set_global "stack", $P0
+ .return($I1)
+.end
+
+=pod
+
STACK_POP:
set I10, P2
unless I10, STACK_POP_POP_1
