Class: GhostWheel::Expression

Inherits:
Object
  • Object
show all
Defined in:
lib/ghost_wheel/expression.rb,
lib/ghost_wheel/expression/rule.rb,
lib/ghost_wheel/expression/empty.rb,
lib/ghost_wheel/expression/query.rb,
lib/ghost_wheel/expression/literal.rb,
lib/ghost_wheel/expression/optional.rb,
lib/ghost_wheel/expression/sequence.rb,
lib/ghost_wheel/expression/transform.rb,
lib/ghost_wheel/expression/look_ahead.rb,
lib/ghost_wheel/expression/repetition.rb,
lib/ghost_wheel/expression/alternation.rb,
lib/ghost_wheel/expression/end_of_file.rb

Defined Under Namespace

Classes: Alternation, Empty, EndOfFile, Literal, LookAhead, Optional, Query, Repetition, Rule, Sequence, Transform

Instance Method Summary collapse

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/ghost_wheel/expression.rb', line 18

def ==(other)
  self.class == other.class
end

#parse(scanner, cache = Hash.new) ⇒ Object 



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# File 'lib/ghost_wheel/expression.rb', line 5

def parse(scanner, cache = Hash.new)
  cache_key = "#{object_id}:#{scanner.pos}"
  cache_hit = cache[cache_key]
  if cache_hit.nil?
    result           = uncached_parse(scanner, cache)
    cache[cache_key] = [result, scanner.pos]
    result
  else
    scanner.pos = cache_hit.last
    cache_hit.first
  end
end