Andreas,
Your 'self answers' all look good.
| spec
| package:'Foo' with:[spec requires: 'Bar'];
| package:'Foo' with:[spec requires: 'Baz'];
|
| and
| spec
| package: 'Foo' with:[spec requires: #('Bar' 'Baz')].
are indeed equivalent. So the difference pieces of the spec can be included in
different #for:do: blocks based on the platform.
To take you a little bit into the internals...You will notice that all
packages/projects/groups are named, so for each spec of a given name an ordered
list of modifications are recorded while resolving the spec on a given platform.
1. all #version: pragmas (no import and therefore self-contained) are
processed
first
2. #version:import: pragmas are processed next (using the imported version as
a
starting point).
3. within a #version: or #version:import: method, the specs are processed in
project attribute order (i.e., for Squeak -> #common, #squeakCommon,
#squeak).
4. the individual statements in the #for:do: for a given attribute are
processed
in order.
5. there are 4 unique operations supported:
- add
- copy
- merge
- remove
Once the initial processing is complete, the operations are collapsed to form
the final named spec. The named specs are collected into the version ....
The #add operation is used by the constructors with 'overrides' in their name.
The #add operation replaces the named spec.
The #copy operation is used the by the #project:copyFrom:with: constructor.
Note that #copy requires that an #add/#merge operation proceeds it in it's list.
The #merge operation merges it's items into the previous version of the named
spec. Not that #merge is equivalent to #add if the name spec doesn't exist yet.
Most of the constructors use the #merge operation.
The #remove operation is used by the constructors with 'remove' in their name.
The #remove operation removes it's from the previous version of the named spec.
So you can imagine that as you traverse through an attribute list for a
particular project, that each of the individual constructor statements for a
named spec are processed in a very specific order with each of the #add, #copy,
#merge, and #remove operations applied in order...
Hope this helps,
Dale
----- "Andreas Raab" <[email protected]> wrote:
| On 5/6/2010 5:26 PM, Dale Henrichs wrote:
| > I don't think I've completely answered your questions so we might
| want to continue the dialog on this question....
|
| We're getting close :-) Let me take my own questions and answer them
| in
| my own words to see if I understand the issues correctly:
|
| Q1: #includes: vs. #requires:
|
| If I understand correctly what you're saying then, in heavily
| simplified
| form, I'd say they're both dependencies, except that #requires: is
| loaded before the package it relates to and #includes: afterwords.
| Thus:
|
| spec package: 'B' with:[
| spec requires: 'A'.
| spec includes: 'C'.
| ].
|
| will load A, B, and C in that order. One thing one can do with this is
|
| to have mutually dependent packages, for example if package Foo and
| Bar
| always must be loaded together (Foo before Bar) one would specify:
|
| spec package: 'Foo' with:[spec includes: 'Bar'].
| spec package: 'Bar' with:[spec requires: 'Foo'].
|
| There is now no way by which Foo or Bar could be loaded without its
| companion. Correct?
|
| Q2: Why is HelpSystem not loaded?
|
| A: That's a bug which I can work around by specifying either #version:
|
| or #versionString:.
|
| Q3: When exactly is HelpSystem loaded?
| A: In the context of my configuration HelpSystem is loaded for two
| reasons: a) because it's a dependency for WebClient-Help and b)
| because
| no 'default' group has been specified it would be loaded implicitly.
|
| Q4: How does one define dependencies that differ based on platform?
| A: I'm not really sure about this. My understanding is that I could
| use
| #includes: to model the dependency in the "for: #pharo" branch, but
| one
| question that is still open is whether the following two expressions
| are
| equivalent:
|
| spec
| package:'Foo' with:[spec requires: 'Bar'];
| package:'Foo' with:[spec requires: 'Baz'];
|
| and
| spec
| package: 'Foo' with:[spec requires: #('Bar' 'Baz')].
|
| Are these equivalent?
|
| Cheers,
| - Andreas
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