Class: PatternMatch::Pattern

Inherits:
Object
  • Object
show all
Includes:
Backtrackable
Defined in:
lib/pattern-match/core.rb,
lib/pattern-match/experimental.rb

Direct Known Subclasses

PatternElement, PatternQuantifier

Defined Under Namespace

Modules: Backtrackable

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Backtrackable

#choice_points

Constructor Details

#initialize(*subpatterns) ⇒ Pattern

Returns a new instance of Pattern.



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# File 'lib/pattern-match/core.rb', line 24

def initialize(*subpatterns)
  @parent = nil
  @next = nil
  @prev = nil
  @subpatterns = subpatterns.map {|i| i.kind_of?(Pattern) ? i : PatternValue.new(i) }
  set_subpatterns_relation
end

Instance Attribute Details

#next ⇒ Object

Returns the value of attribute next.



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# File 'lib/pattern-match/core.rb', line 19

def next
  @next
end

#parent ⇒ Object

Returns the value of attribute parent.



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# File 'lib/pattern-match/core.rb', line 19

def parent
  @parent
end

#prev ⇒ Object

Returns the value of attribute prev.



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# File 'lib/pattern-match/core.rb', line 19

def prev
  @prev
end

Instance Method Details

#!@ ⇒ Object 



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# File 'lib/pattern-match/core.rb', line 52

def !@
  PatternNot.new(self)
end

#&(pattern) ⇒ Object 



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# File 'lib/pattern-match/core.rb', line 44

def &(pattern)
  PatternAnd.new(self, pattern)
end

#ancestors ⇒ Object 



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# File 'lib/pattern-match/core.rb', line 36

def ancestors
  root? ? [self] : parent.ancestors.unshift(self)
end

#append(pattern) ⇒ Object 



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# File 'lib/pattern-match/core.rb', line 102

def append(pattern)
  if @next
    @next.append(pattern)
  else
    if subpatterns.empty?
      if root?
        new_root = PatternAnd.new(self)
        self.parent = new_root
      end
      pattern.parent = @parent
      @next = pattern
    else
      subpatterns[-1].append(pattern)
    end
  end
end

#directly_quantified? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pattern-match/core.rb', line 68

def directly_quantified?
  @next and @next.quantifier?
end

#inspect ⇒ Object 



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# File 'lib/pattern-match/core.rb', line 119

def inspect
  "#<#{self.class.name}: subpatterns=#{subpatterns.inspect}>"
end

#match(vals) ⇒ Object 



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# File 'lib/pattern-match/core.rb', line 84

def match(vals)
  if directly_quantified?
    q = @next
    repeating_match(vals, q.greedy?) do |vs, rest|
      if vs.length < q.min_k
        next false
      end
      vs.all? {|v| yield(v) } and q.match(rest)
    end
  else
    if vals.empty?
      return false
    end
    val, *rest = vals
    yield(val) and (@next ? @next.match(rest) : rest.empty?)
  end
end

#quantified? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pattern-match/core.rb', line 64

def quantified?
   directly_quantified? or (root? ? false : @parent.quantified?)
end

#quantifier? ⇒ Boolean

Returns:

  • (Boolean)

Raises:

  • (NotImplementedError) 


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# File 'lib/pattern-match/core.rb', line 60

def quantifier?
  raise NotImplementedError
end

#quasibinding ⇒ Object 



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# File 'lib/pattern-match/core.rb', line 40

def quasibinding
  vars.each_with_object({}) {|v, h| h[v.name] = v.val }
end

#root ⇒ Object 



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# File 'lib/pattern-match/core.rb', line 72

def root
  root? ? self : @parent.root
end

#root? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pattern-match/core.rb', line 76

def root?
  @parent == nil
end

#to_a ⇒ Object 



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# File 'lib/pattern-match/core.rb', line 56

def to_a
  [self, PatternQuantifier.new(0, true)]
end

#validate ⇒ Object 



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# File 'lib/pattern-match/core.rb', line 80

def validate
  subpatterns.each(&:validate)
end

#vars ⇒ Object 



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# File 'lib/pattern-match/core.rb', line 32

def vars
  subpatterns.flat_map(&:vars)
end

#|(pattern) ⇒ Object 



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# File 'lib/pattern-match/core.rb', line 48

def |(pattern)
  PatternOr.new(self, pattern)
end