String-Handling Simplified with Variable-Length Fields

The RPG Style Guide at http://www.as400network.com/article.cfm?ID=2461


recommends using built-in functions instead of arrays to handle strings. The varying-length character type (available in V4R2 and 
above) can also simplify string-handling code as well as make it more efficient. I recommend using varying-length fields as CONST or VALUE 
parameters to every string-handling subprocedure as well as for string temporaries. (I recently worked with an RPG programmer, and we reduced 
the number of lines in a subprocedure from about 10 icky lines to two simple and straightforward lines, mostly through the use of varying- 
length parameters.) Here's a little example; not only does it look better, but it's also faster (no %TRIMs). Instead of:

C          EVAL   Name = %TRIMR(Lib) + '/' +
C                        %TRIMR(File) + '(' +
C                        %TRIMR(Mbr) + ')'

with variable-length fields, you can use:

C          EVAL   Name = Lib + '/' +
C                        File + '(' +
C                        Mbr + ')'

I thought I should check my claim that this approach is faster, and it turns out it's more than twice as fast to produce "Lib/File(Mbr)", 
where all variables (except "Name") are 10 characters long.

Adapted from a forum message by IBM Toronto's Barbara Morris

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