Add 1 to A to get B, your code

Last week I discussed how I had created a program to maximize the number of values I could have in a 3 character field. I did this using the values 000 – ZZZ. As we all know it is not possible in RPG to just to add 1 to A to get B. I gave the program of how I did it here, and I asked if anyone had another way to do it so send it me.

Several people did, and I am grateful to them for their submissions. If you would like to send one please sent it via the Contact form as the formatting in the comments section will do strange things to it.

• Howard Chen
• Rich Diedrich
• Jon Paris
• Henrik Rutzou

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Howard Chen

Use base 10 to base 36 conversion:

d b36char s 36 INZ('0123456789ABCDEFGHIJKLMN- d OPQSTUVUWXYZ') d i s 10i 0 inz d p s 10i 0 inz d b36n s 10i 0 inz d b36a s 3 inz('0ZZ') /free // convert base 36 number to base 10 for i = 1 to %size(b36a); b36n = b36n * 36 + %scan(%subst(b36a:i:1):b36char)-1; endfor; b36n += 1; // convert base 10 to base 36 for i = %size(b36a) downto 1; p = %rem(b36n:36) + 1; %subst(b36a:i:1) = %subst(b36char:p:1); b36n = %div(b36n:36); endfor; *inlr = *on; return; /end-free

In the example Add 1 to '0ZZ' = '100'

Sorry, I am not totally freed yet.

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Rich Diedrich

I would just create the base 36 conversion routines, that way we can perform whatever calculations we want:

ctl-opt dftactgrp(*no); dcl-c CLIST '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'; dcl-c XLIST X'000102030405060708090A0B0C0D0E0F1011- 12131415161718191A1B1C1D1E1F20212223'; // Main line dcl-s cfield char(3); cfield = '01Z'; cfield = itob36(b36toi(cfield) + 1:%size(cfield)); dsply cfield; return; // Convert a base 36 value to an integer // The C strtoul() function could be used instead of this // The maximum base 36 length of uns(10) is 7 dcl-proc b36toi; dcl-pi *n uns(10); b36val varchar(7) value options(*trim); end-pi; // Access each translated character as a 1 byte integer dcl-ds bval qualified; nval uns(3) dim(7); end-ds; dcl-s i int(10); dcl-s rval uns(10) inz(0); bval = %xlate(CLIST:XLIST:b36val); for i = 1 to %len(b36val); rval = rval * 36 + bval.nval(i); // Base 36 conversion endfor; return rval; end-proc; // Convert an integer to a base 36 value // The result will be trimmed if the length isn't specified dcl-proc itob36; dcl-pi *n varchar(7); ival uns(10) value; length int(10) value options(*nopass); end-pi; dcl-ds bval qualified; nval uns(3) dim(7); end-ds; dcl-s i int(10); dcl-s rval char(7); bval = *allx'00'; i = %size(bval); dow ival <> 0; bval.nval(i) = %rem(ival:36); ival = %div(ival:36); i -= 1; enddo; rval = %xlate(XLIST:CLIST:bval); if %parms > 1; return %subst(rval:8 - length:length); else; return %triml(%subst(rval:1:6):'0') + %subst(rval:7:1); endif; end-proc;

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Jon Paris

I missed the "right" way to do this with my first attempt but ...

I kept thinking this had to be simpler - and indeed it can be. This version just keeps the sequence number as a binary value allowing simple math to be used for incrementing - it then uses a very simple routine to convert to the character "number". This approach will (I think) easily allow for an 8 character "number" if needed with minimal or no code change.

A reverse routine (char "number" to integer) would be equally simple.

Here's the code:

dcl-s charNumber char(3); dcl-s realNumber uns(10) Inz; dcl-s x uns(5); for x = 1 to 2000; realNumber += 1; charNumber = NumberAsChar(realNumber); if %Rem( x: 360 ) = 0; dsply ('At ' + %char(x) + ' number is "' + charNumber + '"'); EndIf; EndFor; *InLR = *On; dcl-proc NumberAsChar; dcl-pi NumberAsChar char(8); inputNumber like(realNumber) Value; end-pi; dcl-s i uns(3); dcl-s work uns(20); dcl-s charWork varchar(8) inz; dcl-ds chars; *n char(36) Inz('0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'); character char(1) pos(1) dim(46); end-ds; Dou inputNumber = 0; work = %Rem(inputNumber: 36); inputNumber /= 36; charWork += character( work + 1 ); EndDo; Return charWork; // All done end-proc;

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Henrik Rutzou

Here is a complete program (actually party written by Hans Boldt)

ltoa terminates with X'00' so if it has to go into a 3 char field any value lower than 3 char will have the terminater in it.

Further more the field base36 must be blanked before ltoa is run.

To solve the problem and in the same time make characters uppercase (strtol is not case sensitive) I suggest this code:

h dftactgrp(*no) actgrp(*new) bnddir('QC2LE') d strtol pr 10i 0 extproc('strtol') d nptr * value options(*string) d endptr * value d base 10i 0 value d ltoa PR * ExtProc('__ltoa') d nuInt 10I 0 Value d szRtnBuffer * Value d nRadix 10I 0 Value d number s 10i 0 d base36 s 32a d i s 10i 0 /free // sets a in base36 number = 10; base36 = *blanks; ltoa(number:%addr(base36):36); for i = 1 to %len(%trim(base36)); %subst(base36:i:1) = %bitor(%subst(base36:i:1):X'40'); endfor ; // converts a to 10, add 1 and reconvert to b in base36 number = strtol(%trim(base36):*null:36); number +=1; base36 = *blanks; ltoa(number:%addr(base36):36); for i = 1 to %len(%trim(base36)); %subst(base36:i:1) = %bitor(%subst(base36:i:1):X'40'); endfor; *inlr = *on; /end-free