Re: MOVEA -> EVAL

Barbara,

At 6/5/01 12:14 PM -0400, you wrote:
>Formerly, MOVEA was the only way to do string processing in RPG, and now
>I think it's often used out of habit where newer string builtin functions
>can handle the same task without bothering with arrays at all.
>
>Anyway, to handle the function of MOVEA using EVAL:
>
>C        MOVEA      arr1(n)     arr2(m)
>C        MOVEA(P)   arr1(n)     arr2(m)
>
>becomes
>
>D src       s         65535a   based(pSrc)
>D tgt       s         65535a   based(pTgt)
>D srcLen    s            10i 0
>D tgtLen    s            10i 0
>  /free
>         pSrc = %addr(arr1) + %size(arr1) * (n - 1)
>         pTgt = %addr(arr2) + %size(arr2) * (m - 1)
>         srcLen = %size(arr1) * (%elem(arr1) - n + 1)
>         %subst(tgt : 1 : srcLen) = %subst(src : 1 : srcLen) // no padding
>
>         tgtLen = %size(arr1) * (%elem(arr1) - n + 1)
>         %subst(tgt : 1 : tgtLen) = %subst(tgt : 1 : srcLen) // padding


  I think that you can admit that, despite the "coolness" of using pointers 
and the new freeform calcs, a one line MOVEA is a lot more elegant and 
easier to understand at a glance.

  Also note that MOVEA can move a variable to an array and vice versa.  All 
this functionality in one easy to read opcode!  How many will take the 
above code (or a variation) and make a subprocedure out of it, essentially 
duplicating what is already in the language??

  I was under the impression that the table was supposed to be a one for 
one replacement and that I missed something.  I would actually like to see 
this opcode "ported" to freeform.

  Thanks.

  -mark

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