Arrow updates

[Brian Rice]

I'm sorry I wasn't available the last few days to handle your 
replies. However, I did have time to work on the code, and found a 
few features I forgot to include or complete, so here are some 
snippets that will round out the 0.1 release. Of the 6, only 3, 4, 
and 5 actually affect the semantics of the existing code. The rest 
simply improve the code as a document. All are available at the usual 
place: http://tunes.org/~water/arrow. In particular, a new changeset 
has been released with these added in, called Arrow-current.cs. I may 
change it to be ArrowsV0.1.1.cs, assuming we don't commit to a 
particular versioning scheme that is too different from this. 
Incidentally, I should mention that the .st format (pure sources) 
will not correctly install the Arrows package due to some 
cross-package dependencies. If I manage to work around this, I will 
restrict the use of ChangeSets to updates, and use .st for release 
snapshots.

I'll get to responding to the e-mails in a bit. I'm still unwinding 
from returning from my trip.

Thanks,
~

-------------------------------------------

Change Set:		1IdentityGraph-btr
Date:			18 June 2001
Author:			Brian T. Rice

Adds the Identity operation representative to Arrow-Relational Ops.

Change Set:		2MiscCommentFixes-btr
Date:			18 June 2001
Author:			Brian T. Rice

Adjusted comments to be more clear and up to date.

Change Set:		3FilterFixes-btr
Date:			18 June 2001
Author:			Brian T. Rice

Added #operand to publically access the direct argument to a given 
filter. Fixes a bug when using filters over FilteredObjectGraphs. 
Modified the code to work with the right abstraction. Also added #>> 
support to all ArrowGraphs, which changes were lost in putting 
together v0.1 Arrow.

Change Set:		4SmalltalkMOP-btr
Date:			18 June 2001
Author:			Brian T. Rice

Miscellaneous fixes and small enhancements to the SmalltalkMOP and its usage.

Change Set:		5ArrowPlusFix-btr
Date:			18 June 2001
Author:			Brian T. Rice

Turns + among arrows and graphs into a commutative operator. 
Previously, arrow>>+ was not delegating to ArrowGraph>>addImmutable:.

Change Set:		6CodeCleanups-btr
Date:			21 June 2001
Author:			Brian T. Rice

These changes don't affect semantics, but make the code more readible 
and make use of higher-level library protocols.