Module: Laborantin::DependencySolver

Included in:
Commands::Analyze, Commands::Run
Defined in:
lib/laborantin/core/dependency_solver.rb

Overview

Poor man’s dependency greedy and recursive algorithm raises an error after two consecutive calls with the same previoulsy_wrong dependencies list we rely on the implementer to not create dependency loops. The whole dependency design is extremely wasteful, but it works.

Instance Method Summary collapse

Instance Method Details

#resolve_dependencies(obj, previously_wrong = []) ⇒ Object 



8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
 
# File 'lib/laborantin/core/dependency_solver.rb', line 8

def resolve_dependencies(obj, previously_wrong=[])
  valid, wrong = obj.class.dependencies.partition do |dep|
    dep.valid?(obj)
  end

  if wrong.empty?
    puts "all dependencies met"
  else
    puts "unmet dependencies: #{wrong.map(&:name).join(' ')}"
    if previously_wrong == wrong
      raise RuntimeError, "already tried resolving these dependencies"
    else
      wrong.each do |dep|
        # Since iterating changes the status of the dependency, we may want to re-test if a dep is valid or not.
        # the assumption is that resolving a dep costs more than testing if it's valid or not
        dep.verifications.each{|v| v.resolve!(obj)} unless dep.valid?(obj) 
      end
      resolve_dependencies(obj, wrong)
    end
  end
end