| William M. Klein 2007-08-28, 9:55 pm |
| Karl and Roger,
OK - I see your problem. There is the IMPLICATION that literals in the "text
manipulation stage" may not be constants, but it certainly isn't explict. (I am
more than happy to do a "defect report" on this - if neither of you do.)
The IMPLICATION is on page 31 where it is describing "text words" (what the text
manipulation stage deals with) where it says,
"2) an alphanumeric, boolean, or national literal including the opening and
closing delimiters that bound the literal;"
Therefore, (unlike numeric literals) I would INFER that something without
literal delimiters is NOT a "valid" literal in the text manipulation stage.
I believe that rule 10 on page 40 should be "expanded" to exclude
constant-names - and the same restriction should be applied to COPY and REPLACE
statements.
--
Bill Klein
wmklein <at> ix.netcom.com
"Karl Kiesel" <Karl.Kiesel@fujitsu-siemens.com> wrote in message
news:fb115t$6kc$1@nntp.fujitsu-siemens.com...
> "William M. Klein" <wmklein@nospam.netcom.com> schrieb im Newsbeitrag
> news:e4EAi.169153$Bo7.88986@fe07.news.easynews.com...
> Bill,
> that is just the problem I see here! The STD2002 defines a sequence of
> separate stages of compilation (see chapter 7) but the earlier stage (text
> manipulation) may need information that can only be obtained from the later
> stage (compilation): expressions within >>IF and >>EVALUATE directives may be
> formed using literals (for example see STD2002 7.2.7.1 syntax rule 1) and i
> did not find any rule, that forbids using a constant in place of a literal in
> these expressions. Therefore, to complete the text manipulation stage, a
> compiler must be able to evaluate constant conditional expressions in
> directives, but this is impossible, if a constant is involved, beause
> processing (ie recognition and especially determining the value) of such a
> constant entry is definitely part of the later stage - but this stage can not
> be entered unless the previous stage has been completed! In this sense, using
> constants within directives is a form of 'forward reference'; If the concept
> of stages within the STD2002 is to be kept - and I would not like to give it
> up! - constant entries are a problem that make implementaion rather hard, if
> not impossible.
>
> Karl Kiesel
> Fujitsu Siemens Computers
>
>
>
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