The SELECT
statement should be used only to clearly define some new branches in the control flow. As soon as a WHEN
clause contains too many statements this highly decreases the readability of the overall control flow statement. In such case, the content of
WHEN
clause should be extracted in a dedicated subroutine.
Noncompliant code example
With the default threshold of 5:
C SELECT
C WHEN X=1
C MOVE A B
C MOVE C D
C MOVE E F
C MOVE J K
C MOVE L M
C WHEN X=2
C ....
C ENDSL
/free
select;
when X=1;
B = A;
D = C;
F = E;
K = J;
M = L;
when X=2;
...
endsl;
/end-free
Compliant solution
C SELECT
C WHEN X=1
C EXSR SR011
C WHEN X=2
C ....
C ENDSL
C ...
C SR011 BEGSR
C MOVE A B
C MOVE C D
C MOVE E F
C MOVE J K
C MOVE L M
C ENDSR
/free
select;
when X=1;
exsr SR011;
when X=2;
...
endsl;
/end-free