Bazaar Search Language brain dump

[Ian Clatworthy]

Jono,

Thinking about our discussion yesterday, I think we could do
something pretty simple yet powerful. I'll write it up as a spec soon.
Here's a brief summary though ...

1. log supports -s as a list option. Each value is a condition.
   (In the future, missing ought to support -s as well.)

2. Conditions are or-ed together by default. The --match-all-searches
   flag makes them and-ed together instead.

3. The syntax of a condition is ...

    attribute operator value

4. Supported attributes should include message, committer, authors
   and nick to begin with.

5. Supported operators are =, contains, in, !=, !contains, !in:

   * '=' is an exact string match
   * 'contains' is a substring match
   * 'in' looks up patterns (see bzr help patterns) in a file
   * ! negates the above.

6. Values are strings. Like revisionspecs and several other places in
   bzr, we support value schemes:

   * me: maps to the currently configured username
   * env:xx maps to the environment variable xx (in a cross-platform way)
   * value:xx maps to xx, allowing escaping of strings that look like a scheme.

Implementation wise, we need a search parser that converts strings
into a useful class, including the and vs or thing. We then extend
the current log filter to match a Revision against that object instead
of just always matching a plain string against the commit message.

Anyhow, something to critique/hack together on the flight to next
week's sprint. :-)

Ian C.