Only run [Transformer.isPrimary] once for each asset/transformer pair.

BUG=16442
R=rnystrom@google.com

Review URL: https://codereview.chromium.org//224933002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@34857 260f80e4-7a28-3924-810f-c04153c831b5
5 files changed
tree: 75e19ef8742dc45386283231f16f8576eb85f7df
  1. examples/
  2. lib/
  3. test/
  4. CHANGELOG.md
  5. LICENSE
  6. pubspec.yaml
  7. README.md
README.md

Barback is an asset build system. It is the library underlying pub's asset transformers in pub build and pub serve.

Given a set of input files and a set of transformations (think compilers, preprocessors and the like), it will automatically apply the appropriate transforms and generate output files. When inputs are modified, it automatically runs the transforms that are affected.

To learn more, see here.