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55bf7de97c
Run the following command over the source: perl -pi.bak -e 's/(20[01][0-9])-2016/$1-2017/g' `git ls-files` (Thanks Rich for the perl snippet, as used in past years.)
67 lines
2.8 KiB
OCaml
67 lines
2.8 KiB
OCaml
(* virt-builder
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* Copyright (C) 2012-2017 Red Hat Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*)
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(** The Planner can plan how to reach a goal by carrying out a series
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of operations. You tag the input state and the output state, and
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give it a list of permitted transitions, and it will return a
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multi-step plan (list of transitions) from the input state to the
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output state.
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For an explanation of the Planner, see:
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http://rwmj.wordpress.com/2013/12/14/writing-a-planner-to-solve-a-tricky-programming-optimization-problem/
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Tags are described as OCaml association lists. See the OCaml
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{!List} module.
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Transitions are defined by a function (that the caller supplies)
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which returns the possible transitions for a given set of tags,
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and for each possible transition, the weight (higher number =
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higher cost), and the tag state after that transition.
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The returned plan is a list of transitions.
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The implementation is a simple breadth-first search of the tree of
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states (each edge in the tree is a transition). It doesn't work
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very hard to optimize the weights, so the returned plan is
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possible, but might not be optimal. *)
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type ('name, 'value) tag = 'name * 'value
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type ('name, 'value) tags = ('name, 'value) tag list
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(** An assoc-list of tags. *)
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type ('name, 'value, 'task) plan =
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(('name, 'value) tags * 'task * ('name, 'value) tags) list
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type ('name, 'value, 'task) transitions_function =
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('name, 'value) tags -> ('task * int * ('name, 'value) tags) list
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val plan : ?max_depth:int -> ('name, 'value, 'task) transitions_function -> ('name, 'value) tags -> ('name, 'value) tags * ('name, 'value) tags -> ('name, 'value, 'task) plan
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(** Make a plan.
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[plan transitions itags (goal_must, goal_must_not)] works out a
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plan, which is a list of tasks that have to be carried out in
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order to go from the input tags to the goal. The goal is passed
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in as a pair of lists: tags that MUST appear and tags that MUST
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NOT appear.
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The returned value is a {!plan}.
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Raises [Failure "plan"] if no plan was found within [max_depth]
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transitions. *)
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