Class: Ibex::Runtime::CST::TokenMemo

Inherits:
Object
  • Object
show all
Defined in:
lib/ibex/runtime/cst/incremental/token_memo.rb

Overview

Session-local token metadata used to validate lexical resynchronization.

Constant Summary collapse

ENTRY_BYTES =

: Integer

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Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(tokens:, offsets:, states:) ⇒ TokenMemo

Returns a new instance of TokenMemo.

Raises:

  • (ArgumentError) 


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# File 'lib/ibex/runtime/cst/incremental/token_memo.rb', line 16

def initialize(tokens:, offsets:, states:)
  unless tokens.length == offsets.length && offsets.length == states.length
    raise ArgumentError, "token memo arrays must have equal lengths"
  end

  ordered = (0...[offsets.length - 1, 0].max).all? do |index|
    offsets.fetch(index) <= offsets.fetch(index + 1)
  end
  raise ArgumentError, "token memo offsets must be ordered" unless ordered

  @tokens = tokens.dup.freeze
  @offsets = offsets.dup.freeze
  @states = states.dup.freeze
  freeze
end

Instance Attribute Details

#offsets ⇒ Object (readonly)

: Array



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# File 'lib/ibex/runtime/cst/incremental/token_memo.rb', line 12

def offsets
  @offsets
end

#states ⇒ Object (readonly)

: Array



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# File 'lib/ibex/runtime/cst/incremental/token_memo.rb', line 13

def states
  @states
end

#tokens ⇒ Object (readonly)

: Array



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# File 'lib/ibex/runtime/cst/incremental/token_memo.rb', line 11

def tokens
  @tokens
end

Class Method Details

.from_root(root, states: []) ⇒ Object 



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# File 'lib/ibex/runtime/cst/incremental/token_memo.rb', line 33

def self.from_root(root, states: [])
  tokens = root.tokens.map(&:green)
  offsets = [] #: Array[Integer]
  offset = 0
  tokens.each do |token|
    offsets << offset
    offset += token.full_width
  end
  actual_states = Array.new(tokens.length) { |index| states.fetch(index, :INITIAL) }
  new(tokens: tokens, offsets: offsets, states: actual_states)
end

Instance Method Details

#damage_index(edits) ⇒ Object

The first token whose owned full span contains or follows an edit.



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# File 'lib/ibex/runtime/cst/incremental/token_memo.rb', line 47

def damage_index(edits)
  normalized = TextEdit.normalize(edits)
  edit = normalized.first
  return unless edit

  point = edit.start
  @tokens.each_index do |index|
    start = @offsets.fetch(index)
    finish = start + @tokens.fetch(index).full_width
    return index if point < finish || (start == point && finish == point)
  end
  @tokens.empty? ? nil : @tokens.length - 1
end

#estimated_bytes ⇒ Object 



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# File 'lib/ibex/runtime/cst/incremental/token_memo.rb', line 62

def estimated_bytes = @tokens.length * ENTRY_BYTES