On 18 Jun 2013 11:24, Marco Facchinetti wrote:
Just curious why an item defined with the TEMPLATE keyword is valid
as %SIZE's argument but not for %LEN.
I have no access to the text of that message RNF0655. What was the
context of the failed reference; i.e. what was the line of code... as a
declarative or a run-time statement?
http://pic.dhe.ibm.com/infocenter/iseries/v7r1m0/topic/rzasd/sc092508560.htm#wq806
_i TEMPLATE i_
"The TEMPLATE keyword indicates that the definition is to be used only
for further LIKE or LIKEDS definitions. The TEMPLATE keyword is valid
for Data Structure definitions and Standalone field definitions."
Thus if %LEN(template_var) was referenced in a run-time expression [a
statement vs a declare], then I would expect that utilization would
fail, per the aforementioned restriction; i.e. the /template/ exists
only for the LIKExx. If the %LEN() is really preferred over %SIZE(),
then just reference what was defined /like/ that template, instead of
naming the TEMPLATE declarative.
For a declarative however, I would expect the same capability as with
a BASED storage declaration. Thus if the based declarative can be
specified for %LEN(), I would expect the TEMPLATE declarative could as
well. And while a based declarative could be utilized at run-time after
the basing pointer was set, the TEMPLATE would have no similar ability
to be referenced in run-time because there is no capability for the
effect [template-only] declarative to be addressed.
http://pic.dhe.ibm.com/infocenter/iseries/v7r1m0/topic/rzasd/sc092508852.htm#lnright
_i %LEN Used for its Value
"... the number of digits or characters of the variable expression.
...
For character, graphic, or UCS-2 expressions the value returned is the
number of characters in the value of the expression. For variable-length
values, such as the value returned from a built-in function or a
variable-length field, the value returned by %LEN is the current length
of the character, graphic, or UCS-2 value.
Note that if the parameter is a built-in function or expression that has
a value computable at compile-time, the length returned is the actual
number of digits of the constant value rather than the maximum possible
value that could be returned by the expression.
..."
An argument that the %LEN() is available only for run-time overlooks
that a constant can be assigned. Thus the capability could conceivably
exist for the use of %LEN() on a declaration for any declarative that is
either a scalar or a DS with a fixed "size" known at compile-time [just
as stated in the above doc snippet]. Arguably, %SIZE() can be used
instead to get bytes, and then multiply according to data type; e.g.
multiply by .5 for a graphic scalar to get the character count. But
that subtle difference between what %LEN() and %SIZE() provide, alludes
to the possible value for the capability that a %LEN(template_var) might
provide vs what %SIZE(template_var) provides.
http://pic.dhe.ibm.com/infocenter/iseries/v7r1m0/topic/rzasd/sc092508749.htm#bifsint
"Built-in functions ... [w]hen used with definition specification
keywords, the value of the built-in function must be known at compile
time and the argument cannot be an expression."
http://pic.dhe.ibm.com/infocenter/iseries/v7r1m0/topic/rzasd/sc092508874.htm#bbsize
"%SIZE may be specified anywhere that a numeric constant is allowed on
the definition specification and in an expression in the extended factor
2 field of the calculation specification."
midrange.com
