Karl Czajkowski wrote:
On Mar 08, Andreas Savva loaded a tape reading:
Karl, Michel
Karl Czajkowski wrote:
On Mar 07, Michel Drescher loaded a tape reading:
1) Argument list handling in jsdl:Application Basically, the modeling of command line arguments in a whole string is ... cumbersome? I know, it works, but it looks ugly.
Michel, I think the word you were looking for was 'simple.' ;-)
It is "simple" right up until you need to pass through strings that have your separator whitespace, or quote marks, or what have you embedded in one program argument! I think it is much simpler to maintain structured data than it is to try to embed funny serializations of structured data into the JSDL info set model. This is particularly so when a consumer of this document needs to translate the structure into some arbitrarily different structure or serialized syntax to safely pass it through local implementation layers.
It's 'simple' and covers many cases but complicated cases make it very complex. :-) Your description of the problems is good and I like having the extra structure. I know argument parsing is a black art. I think our assumption might have been that the contents would go through as-is, unseen and untouched and not our problem. (We did actually allow more than one argument in the distant past.) Andreas
That was certainly our experience in trying to make GRAM RSL sane... I often regretted the fact that we didn't use as much explicit parenthetic grouping for arguments as we did for environment variables, because users often made bad assumptions about where the argument strings were separated versus treated as one string that needed to be "reparsed". Our (pre-WS) RSL parser explicitly represented a sequence of strings in the right-hand side of the "arguments" clause parse, and we had a somewhat standard whitespace, quoting, and quote-escape mechanism to allow people to express any possible argument list.
For example:
(arguments= foo bar baz )
was a shorthand for:
(arguments="foo" "bar" "baz")
and you could get whitespace or a stray quote in with:
(arguments="foo bar" "baz""spliced")
which would render as this in the current proposal:
<arguments> <argument>foo bar</argument> <argument>baz"spliced</argument> </arguments>
which I certainly think is more obvious than the RSL way. :-)
I suppose the only tricky one now would be getting angle brackets in there:
<argument><not a tag></argument>
karl
-- Andreas Savva Fujitsu Laboratories Ltd