Rake 0.7.0 Released


#1

= Rake 0.7.0 Released

These changes for Rake have been brewing for a long time. Here they
are, I hope you enjoy them.

== Change Summary

=== New Features

  • Name space support for task names (see below).

  • Prerequisites can be executed in parallel (see below).

  • Added safe_ln support for openAFS (via Ludvig Omholt).

  • RDoc defaults to internal (in-process) invocation. The old behavior
    is still available by setting the +external+ flag to true.

  • Rakefiles are now loaded with the expanded path to prevent
    accidental polution from the Ruby load path.

  • Task objects my now be used in prerequisite lists directly.

  • Task objects (in addition to task names) may now be included in the
    prerequisite list of a task.

  • Internals cleanup and refactoring.

=== Bug Fixes

  • Compatibility fixes for Ruby 1.8.4 FileUtils changes.

== What is Rake

Rake is a build tool similar to the make program in many ways. But
instead of cryptic make recipes, Rake uses standard Ruby code to
declare tasks and dependencies. You have the full power of a modern
scripting language built right into your build tool.

== New Feature Details

=== Namespaces

Tasks can now be nested inside their own namespaces. Tasks within one
namespace will not accidently interfer with tasks named in a different
namespace.

For example:

namespace “main” do
task :build do
# Build the main program
end
end

namespace “samples” do
task :build do
# Build the sample programs
end
end

task :build_all => [“main:build”, “samples:build”]

Even though both tasks are named :build, they are separate tasks in
their own namespaces. The :build_all task (defined in the toplevel
namespace) references both build tasks in its prerequisites.

You may invoke each of the individual build tasks with the following
commands:

rake main:build
rake samples:build

Or invoke both via the :build_all command:

rake build_all

Namespaces may be nested arbitrarily. Since the name of file tasks
correspond to the name of a file in the external file system,
FileTasks are not affected by the namespaces.

See the Rakefile format documentation (in the Rake API documents) for
more information.

=== Parallel Tasks

Sometimes you have several tasks that can be executed in parallel. By
specifying these tasks as prerequisites to a +multitask+ task.

In the following example the tasks copy_src, copy_doc and copy_bin
will all execute in parallel in their own thread.

multitask :copy_files => [:copy_src, :copy_doc, :copy_bin] do
puts “All Copies Complete”
end

== Availability

The easiest way to get and install rake is via RubyGems …

gem install rake (you may need root/admin privileges)

Otherwise, you can get it from the more traditional places:

Home Page:: http://rake.rubyforge.org/
Download:: http://rubyforge.org/project/showfiles.php?group_id=50

== Thanks

As usual, it was input from users that drove a alot of these changes.
The following people either contributed patches, made suggestions or
made otherwise helpful comments. Thanks to …

  • Doug Young (inspriation for the parallel task)

  • David Heinemeier H. (for --trace message enhancement and for
    pushing for namespace support).

  • Ludvig Omholt (for the openAFS fix)

– Jim W.


#2

Jim W. wrote:

  • Name space support for task names (see below).

rake main:build
rake samples:build

Namespaces may be nested arbitrarily. Since the name of file tasks
correspond to the name of a file in the external file system,
FileTasks are not affected by the namespaces.

This looks very interesting, but I don’t understand why you went with a
single colon instead of the most common double colon.


import import
import name
import signature
reimport import
import python

– /me


#3

why_ wrote:

This looks very interesting, but I don’t understand why you went with a
single colon instead of the most common double colon.

Good question!

There were a number of different delimiter characters I considered. The
“/” was a possibility but I felt there would be too much confusion with
file pathnames. I looked at ways of overloading an operator on symbols
so that I could say things like

task :main.build

(notice the task name is not quoted). But in the end felt that the
single colon worked fine without introducing too many ambiguities.

Would a double colon have worked? I’m sure it would. And the implied
relationship to Ruby Modules/Class name scoping might have been an
advantage. But then, it might have been a disadvantage as well, for
Rake namespaces are not the same thing as Ruby Modules. It was a toss
up and the single colon won in my mind.

– Jim W.