Module: Trailblazer::Activity::DSL::Linear::Sequence::Compiler

Defined in:
lib/trailblazer/activity/dsl/linear/sequence/compiler.rb

Overview

Compile a Schema by computing implementations and intermediate from a Trailblazer::Activity::DSL::Linear::Sequence.

Class Method Summary collapse

Class Method Details

.call(sequence, find_stops: method(:find_termini), find_start: method(:find_start_task_id)) ⇒ Object 



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# File 'lib/trailblazer/activity/dsl/linear/sequence/compiler.rb', line 23

def call(sequence, find_stops: method(:find_termini), find_start: method(:find_start_task_id))
  _implementations, intermediate_wiring =
    sequence.inject([[], []]) do |(implementations, intermediates), seq_row|
      _magnetic_to, task, connections, data = seq_row
      id = data[:id]

      # execute all {Search}s for one sequence row.
      connections = find_connections(seq_row, connections, sequence)

      # FIXME: {:extensions} should be initialized
      implementations += [[id, Schema::Implementation::Task(task, connections.collect { |output, _| output }, data[:extensions] || [])]]

      intermediates += [
        [
          Schema::Intermediate::TaskRef(id, data),
          # Compute outputs.
          connections.collect { |output, target_id| Schema::Intermediate::Out(output.semantic, target_id) }
        ]
      ]

      [implementations, intermediates]
    end

  start_task_id         = find_start.(intermediate_wiring)
  terminus_to_semantic  = find_stops.(intermediate_wiring)

  intermediate   = Schema::Intermediate.new(intermediate_wiring.to_h, terminus_to_semantic, start_task_id)
  implementation = _implementations.to_h

  Schema::Intermediate::Compiler.(intermediate, implementation) # implemented in the generic {trailblazer-activity} gem.
end

.find_connections(seq_row, searches, sequence) ⇒ Object

Execute all search strategies for a row, retrieve outputs and their respective target IDs.



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# File 'lib/trailblazer/activity/dsl/linear/sequence/compiler.rb', line 59

def find_connections(seq_row, searches, sequence)
  searches.collect do |search|
    output, target_seq_row = search.(sequence, seq_row) # invoke the node's "connection search" strategy.

    target_seq_row = sequence[-1] if target_seq_row.nil? # connect to an End if target unknown. # DISCUSS: make this configurable, maybe?

    [
      output,
      target_seq_row.id
    ]
  end
end

.find_start_task_id(intermediate_wiring) ⇒ Object

The first task in the wiring is the default start task.



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# File 'lib/trailblazer/activity/dsl/linear/sequence/compiler.rb', line 19

def find_start_task_id(intermediate_wiring) # FIXME: shouldn't we use sequence here? and Row#id?
  intermediate_wiring.first.first.id
end

.find_termini(intermediate_wiring) ⇒ Object

Default strategy to find out what’s a stop event is to inspect the TaskRef’s :stop_event.



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# File 'lib/trailblazer/activity/dsl/linear/sequence/compiler.rb', line 11

def find_termini(intermediate_wiring)
  intermediate_wiring
    .find_all { |task_ref, _| task_ref.data[:stop_event] }
    .collect  { |task_ref, _| [task_ref.id, task_ref.data.fetch(:semantic)] }
    .to_h
end