Class: Roby::EventConstraints::Explanation

Inherits:
Object
  • Object
show all
Defined in:
lib/roby/event_constraints.rb

Overview

An explanation for a given predicate value. predicate is the predicate, elements the explanations for predicate having reached the value.

elements is an array of Event and EventGenerator instances.

If an Event is stored there, the explanation is that this event has been emitted.

If an EventGenerator is stored there, the reason depends on value. If value is nil (static), the reason is that the generator is unreachable. If value is false (not emitted), it is that the generator did not emit.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(value, predicate, elements) ⇒ Explanation

Returns a new instance of Explanation.



308
309
310
311
312
 
# File 'lib/roby/event_constraints.rb', line 308

def initialize(value, predicate, elements)
    @value = value
    @predicate = predicate
    @elements = elements
end

Instance Attribute Details

#elements ⇒ Object (readonly)

The elements of explanation



302
303
304
 
# File 'lib/roby/event_constraints.rb', line 302

def elements
  @elements
end

#predicate ⇒ Object (readonly)

The predicate that we are providing an explanation for



300
301
302
 
# File 'lib/roby/event_constraints.rb', line 300

def predicate
  @predicate
end

#value ⇒ Object

Representation of what is being explained. It is true if it is explaining why a predicate is true, false if it is explaining why it is false and nil for static.



298
299
300
 
# File 'lib/roby/event_constraints.rb', line 298

def value
  @value
end

Instance Method Details

#pretty_print(pp, context_task: nil) ⇒ Object 



331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
 
# File 'lib/roby/event_constraints.rb', line 331

def pretty_print(pp, context_task: nil)
    if value == false
        predicate.pretty_print(pp)
        pp.text " is false"
    elsif value == true
        predicate.pretty_print(pp)
        pp.text " is true"
    elsif value.nil?
        pp.text "the value of "
        predicate.pretty_print(pp)
        pp.text " will not change anymore"
    end

    pp.nest(2) do
        elements.each do |explanation|
            pp.breakable
            case explanation
            when Event
                pp.text "the following event has been emitted:"
            when EventGenerator
                if value.nil?
                    pp.text "the following event is unreachable:"
                elsif value == true
                    pp.text "the following event is reachable, "\
                            "but has not been emitted:"
                else
                    pp.text "the following event has been emitted:"
                end
            end

            pp.breakable
            explanation.pretty_print(
                pp, context_task: context_task
            )
            case explanation
            when Event
                sources = explanation.all_sources
                unless sources.empty?
                    pp.breakable
                    pp.breakable
                    pp.text "The emission was caused by the following events"
                    sources.each do |ev|
                        pp.breakable
                        pp.text "< "
                        ev.pretty_print(
                            pp,
                            context: false, context_task: context_task
                        )
                    end
                end

            when EventGenerator
                if value.nil? && explanation.unreachability_reason
                    pp.breakable
                    pp.breakable
                    pp.text "The unreachability was caused by"
                    pp.nest(2) do
                        pp.breakable
                        explanation.unreachability_reason.pretty_print(pp)
                    end
                end
            else
                explanation.pretty_print(pp)
            end
        end
    end
end

#report_exceptions_on(e) ⇒ Object 



314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
 
# File 'lib/roby/event_constraints.rb', line 314

def report_exceptions_on(e)
    elements.each do |el|
        case el
        when Explanation
            el.report_exceptions_on(e)
        when Exception
            e.report_exceptions_from(el)
        when Event
            el.all_sources.each do |ev|
                e.report_exceptions_from(ev)
            end
        when EventGenerator
            e.report_exceptions_from(el.unreachability_reason) if value.nil?
        end
    end
end

#simple? ⇒ Boolean

Returns:

  • (Boolean) 


304
305
306
 
# File 'lib/roby/event_constraints.rb', line 304

def simple?
    elements.size == 1 && !elements.first.kind_of?(Explanation)
end