Class: Ibex::LALR::IELRPartition

Inherits:
Object
  • Object
show all
Defined in:
lib/ibex/lalr/ielr_partition.rb

Overview

Deterministically merges compatible canonical LR(1) states and splits partitions until their outgoing transitions are congruent.

Constant Summary collapse

AUGMENTED_PRODUCTION =

@rbs! type contribution_action = [:shift] | [:reduce, Integer] | [:accept]

-1 #: Integer

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(grammar, states, transitions, profile: false) ⇒ IELRPartition

Returns a new instance of IELRPartition.



27
28
29
30
31
32
33
34
35
 
# File 'lib/ibex/lalr/ielr_partition.rb', line 27

def initialize(grammar, states, transitions, profile: false)
  @grammar = grammar
  @states = states
  @transitions = transitions
  @contributions = Array.new(states.length) { |state_id| action_contributions(state_id) }
  @initial_partition_count = nil
  @final_partition_count = nil
  @profile = profile
end

Instance Attribute Details

#final_partition_count ⇒ Object (readonly)

: Integer?



24
25
26
 
# File 'lib/ibex/lalr/ielr_partition.rb', line 24

def final_partition_count
  @final_partition_count
end

#initial_partition_count ⇒ Object (readonly) 



23
24
25
 
# File 'lib/ibex/lalr/ielr_partition.rb', line 23

def initial_partition_count
  @initial_partition_count
end

Instance Method Details

#build ⇒ Object 



38
39
40
41
42
43
44
45
46
47
48
49
50
51
 
# File 'lib/ibex/lalr/ielr_partition.rb', line 38

def build
  partitions = initial_partitions
  @initial_partition_count = partitions.length if @profile
  partitions = refine_transitions(partitions)
  @final_partition_count = partitions.length if @profile
  indexes = partition_indexes(partitions)
  items = partitions.map { |members| merge_items(members) }
  transitions = partitions.map do |members|
    @transitions.fetch(members.first).to_h do |symbol_id, target|
      [symbol_id, indexes.fetch(target)]
    end
  end
  [items, transitions]
end