On Friday, 16 February 2018 at 18:16:12 UTC, H. S. Teoh wrote:
On Mon, Feb 12, 2018 at 10:35:06AM +0000, Russel Winder via
Digitalmars-d wrote:
In all the discussion of Dub to date, it hasn't been pointed
out that JVM building merged dependency management and build a
long time ago. Historically:
Make → Ant → Maven → Gradle
and Gradle can handle C++ as well as JVM language builds.
So the integration of package management and build as seen in
Go, Cargo, and Dub is not a group of outliers. Could it be
then that it is the right thing to do. After all package
management is a dependency management activity and build is a
dependency management activity, so why separate them, just
have a single ADG to describe the whole thing.
I have no problem with using a single ADG/DAG to describe the
whole thing. However, a naïve implementation of this raises a
few issues:
If a dependent node requires network access, it forces network
access every time the DAG is updated. This is slow, and also
unreliable: the shape of the DAG could, in theory, change
arbitrarily at any time outside the control of the user.
Oh, come on. Immutable artifacts make this matter trivial - the
first step is resolution, where you figure out what things you
already have by looking at metadata only, followed by download
the world (or part you do not have). Since specific versions
never change, nothing to worry about. Java folks had this for
ages with Maven and its ilk.
Some targets like deploy may indeed not have a cheap “check if
its done” step. They may not realy need one. (though rsync does
wonders at minimizing the work)
Also most if not all build systems will inevitably integrate all
of the below in some way:
- compiler (internal as library or external as a build server)
- source code dependency resolution
- package dependency resolution
- package download or build
- execution of arbitrary tasks in form of plugins or external
tools
Me personally in love with plugins and general purpose language
available to define tasks. Scala’s SBT may have many faults but
plugins and extensibility make it awesome.
