[lilycore-dev] Re: SLCP variable vs non-variable length string (PR#479)

[Christian R. <lil...@ce...>]

Allen,

  This has been fixed with the following language:

One cornerstone of SLCP is the variable length string. The format
is '<kbd>ATTRIBUTE=n=STRING</kbd>', where <kbd>n</kbd> indicates
the length of such a string. Though the attribute names are usually
described in uppercase, they can appear in the protocol in any case.
The rules for when a string is to be length prefixed are as follows:
<ul>
<li>If the string is directly user controlled, then it <b>MUST</b>
    be prefixed.
<li>If the string is from a set which the server administrator can
    control, then it <b>MUST</b> be prefixed.
<li>If the string is designed for direct display to the user, then
    it <b>MUST</b> be prefixed.
<li>If the string serializes a list of arbitrary length, regardless
    of whether the delimiter is know, then it <b>MUST</b> be prefixed.
<br>
<li>If the value is an integer, float, or object number, then it
    should not be prefixed.
<li>If the value is a string specified by the protocol itself, then
    it should not be prefixed (i.e. EVENT=eventname).
</ul>
If you should ever notice an attribute which fails to conform to
these rules, please report it as an URGENT bug immediately. It
is most certainly a mistake.<p>

christian

> User: [#121] prisoner
> MOO: 1.8.1+g1+s
> Core: lily running rev 2.6.2
> Server Time: Sun Aug 11 10:14:03 2002 EDT
> ---%report%----
> The documentation for SLCP at
>   http://lilycore.sourceforge.net/Simple%20lily%20Client%20Protocol.html
> documents that strings with a length attribute are good, and documents
> their precise use.  In command documentation, however, it illustrates
> strings without a length attribute (for example, the %USER STATE 
> attribute).
> Please clarify the documentation about the following:
> - When can/will/may/must length-free variables be used?
> - What flexability do parsers have in interpreting fields?  Should/must
>   they allow length-free attributes when the spec has illustrated it
>   with a length and vice-versa?
> - What flexability do generators have in creating fields?  Must they
>   use the exact format given, can they be flexible in using "best
>   judgement" for when to use length and when not, or should they always
>   use length for non-numeric data?
> 
> ---%report%----
> 
>