[eclipse-dev] variables, expressions and other small things...

[Jeff McAffer <Jeff_McAffer@xxxxxxxxxx>]

Some time ago I took the responsibility
for reviewing where generally useful but small bit of function like variables,
expressions etc should live in Eclipse.  Unless there is a strong
argument to the contrary, these will be packaged as plugins in their own
right.  This has a number of benefits (+) and a few drawbacks (-).

+ classes are shared => objects can
be shared
+ uses the Eclipse component mechanism
(dependencies, packaging, ...) 
+ allows for independent evolution/updating/use
+ scalable solution

- classloader overhead per plugin
- more plugins

The main alternatives considered were

1) growing a "utilities" plugin:
 This is appealing in its simplicity but has issues in factoring (I
only want some of the utils...), maintenance (who owns/tests/maintains
it), scale (after a year or two the utils bucket gets big)

2) copy the code: typically the utils
code is small so hey, why not just copy it when you need it?  Individually
small but if everyone needs it... (just say "StringMatcher" or
"Assert"), saves on classloaders but increases potential for
ClassCastExceptions, update/maintenance (how do you patch or even find
all N copies).

The proposed approach still allows someone
to copy the code if they want to maintain it and are concerned about classloader
space and it in general avoids the downsides of the other approaches.

Jeff