C C C I P O P C C POP AN ITEM OFF OF THE STACK C C THIS FUNCTION POPS AN ITEM OFF OF THE STACK.IF THERE ARE NO ITEMS C ON THE STACK AN ERROR FLAG IS RETURNED. THE CALLING SEQUENCE IS: C C IFLAG = IPOP ( ITEM ) C C WHERE C IFLAG- INTEGER VARIABLE USED AS A FLAG.IFLAG WILL BE 0 IF AN C ITEM WAS POPED OFF THE STACK.IF THE STACK WAS INITIALLY C EMPTY IFLAG WILL BE SET TO -1 . C ITEM- INTEGER VARIABLE WHICH WILL CONTAIN THE POPED ITEM IF C THE STACK IS NOT EMPTY.IF THE STACK WAS INITIALLY EMPTY C ITEM IS NOT CHANGED. C FUNCTION IPOP ( ITEM ) INCLUDE 'PSHPOP.CMN' IF ( STKIDX .LE. 0 ) GO TO 10 ITEM= PSTACK(STKIDX) STKIDX = STKIDX - 1 IPOP = 0 GO TO 20 10 CONTINUE IPOP = -1 20 CONTINUE D WRITE (4,1) ITEM D 1 FORMAT (' IPOP POPPED ',I6) RETURN END