MI gurus, It finally dawned on me tonight that a short MI program may easily circumvent a restriction I have in dealing with V3R2 clients, namely the lack of pointer arithmetic. Up to know I've been using the RPG array technique, but it is limited to 32K chunks. I'm using more User Spaces now, and wanted a cleaner way to handle pointers without regard to size constraints. Enter MI. Here is my very first MI program, so be gentle with your critique, but I am asking for constructive criticism. Here is the source to what I named PTRMATH: DCL SPCPTR .PTR PARM; DCL SPCPTR PTR BAS(.PTR); DCL SPCPTR .INCR PARM; DCL DD INCR BIN(4) BAS(.INCR); DCL SPCPTR .OPCODE PARM; DCL DD OPCODE CHAR(3) BAS(.OPCODE); DCL OL *ENTRY(.PTR, .INCR, .OPCODE) PARM EXT MIN(2); DCL DD NUM_PARM BIN(4); /****************************************************************/ ENTRY * (*ENTRY) EXT; STPLLEN NUM_PARM; /* How many parms? */ CMPNV(B) NUM_PARM,2/EQ(ADD); /* Assume ADD opcode */ CMPBLA(B) OPCODE,"SUB"/EQ(SUB); /* Do SUB if parm 3 is */ CMPBLA(B) OPCODE,"- "/EQ(SUB); /* either SUB or - */ ADD: ADDSPP PTR, PTR, INCR; /* Increase pointer */ RTX *; SUB: SUBSPP PTR, PTR, INCR; /* Decrease pointer */ RTX *; PEND; Then, to use it from RPG, I set up these two prototypes: D AddToPtr PR ExtPgm( 'PTRMATH' ) D BasePtr * D Increment 10I 0 Const D PtrMath PR ExtPgm( 'PTRMATH' ) D BasePtr * D Increment 10I 0 Const D OpCode 3 Const Options( *NoPass ) This lets me perform simple pointer arithmetic, to wit: C Callp AddToPtr( ptrLstEnt: ListLen ) C Callp PtrMath( ptrData: 1: 'SUB' ) Since pointer addition is much more frequent than subtraction (in my coding anyway), I thought a simple two parm prototype would be the most readable. I could have made two distinct programs, one for add and one for subtract, but wanted to see if I could do it with just one external program. The hardest part was figuring out how to handle a variable number of entry parms -- all of the samples posted to this list so far used a fixed number AFAIK. The program appears to work correctly in my testing thus far, but I have not benchmarked it yet to see how much overhead is added by the dynamic call. Question: Is using RTX * similar to exiting with LR on or off? Does it even matter when the code has no initialization routines or files to open? Signed, A MI-wannabe +--- | This is the MI Programmers Mailing List! | To submit a new message, send your mail to MI400@midrange.com. | To subscribe to this list send email to MI400-SUB@midrange.com. | To unsubscribe from this list send email to MI400-UNSUB@midrange.com. | Questions should be directed to the list owner/operator: firstname.lastname@example.org +---
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