RE: HereDoc

["Morgan, Paul" <Paul.Morgan@xxxxxxxxxxx>]

Mark,

Have you considered a compile time array or INZ on a variable to get around coding the SQL statement directly in the calculations?  You'd have different syntax because of the different position of the text in the program.

Paul

Principal Programmer Analyst
IT Supply Chain/Replenishment


-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Mark Murphy/STAR BASE Consulting Inc.
Sent: Thursday, January 20, 2011 9:46 AM
To: RPG programming on the IBM i/System i
Subject: HereDoc

Some time ago I learned PHP, and was introduced to a concept called 
HereDoc.  Essentially a way to insert a string inline.  Didn't really see 
the use of it, and never really thought about it much until now.  I have a 
piece of code where it would be highly useful for improving the 
readability of my program.  Unfortunately  The use is in an RPG program, 
and the feature does not exist there.

Anyway here is what I was thinking.  I am using dynamic SQL in a 
particular program (so that I can use set schema to direct unqualified 
references to the environment of my choice).  Some of the SQL commands are 
quite complex, and I have to double quotes in my string literals.  the 
whole thing degenerates into a bunch of extra quotes and continuation 
marks that would not be necessary with a HereDoc.

Consider the following (very simple, but serves to make the point):

       updateStmt =
         'Update MCPSRV Set SESCLS=''O'',                        ' +
         '  semdat = Date_As_Cymd(Current_Date),                 ' +
         '  semtim = time_As_Hms(Current_Time), seuser = user,   ' +
         '  sempgm = ''SQL''                                     ' +
         'Where SEICD9=''V2020Z'''; 

With a HereDoc I could write something like:

       updateStmt = <<<DOC
         Update MCPSRV Set SESCLS='O', 
           semdat = Date_As_Cymd(Current_Date), 
           semtim = time_As_Hms(Current_Time), seuser = user, 
           sempgm = 'SQL' 
         Where SEICD9='V2020Z' 
      <<<DOC

Even with a simple example the lack of superfluous quotes and continuation 
marks makes the second far more readable than the first.

Any thoughts?

Mark Murphy
STAR BASE Consulting, Inc.
mmurphy@xxxxxxxxxxxxxxx