Class: Rutile::NFA

Inherits:
Object
  • Object
show all
Defined in:
lib/rutile/nfa.rb

Defined Under Namespace

Classes: Node

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(str = [], opp = false, value = :transition_state, dummy: false) ⇒ NFA

Returns a new instance of NFA.



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# File 'lib/rutile/nfa.rb', line 69

def initialize(str = [], opp = false, value = :transition_state, dummy: false)
    if !(dummy)
        @nodes = Array.new(2) {|x| Node.new x }
        @start = @nodes.first.pos
        @end = @nodes.last.pos
    
        val = opp ? :not : @end
    
        if opp
            @nodes[@start].set_not [@end]
        end
        
        str.each do |char|
            if char == :dot
                throw Exception.new ("can't be not AND dot.") if val == :not
                @nodes[@start].set_not([val])
                @nodes[@start].empty("\n")
            else
                @nodes[@start].add(char, val)
            end
        end
    end
    
    @new_stack = []
    @old_stack = []
end

Instance Attribute Details

#end ⇒ Object

Returns the value of attribute end.



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# File 'lib/rutile/nfa.rb', line 67

def end
  @end
end

#new_stack ⇒ Object

Returns the value of attribute new_stack.



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# File 'lib/rutile/nfa.rb', line 67

def new_stack
  @new_stack
end

#nodes ⇒ Object

Returns the value of attribute nodes.



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# File 'lib/rutile/nfa.rb', line 67

def nodes
  @nodes
end

#old_stack ⇒ Object

Returns the value of attribute old_stack.



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# File 'lib/rutile/nfa.rb', line 67

def old_stack
  @old_stack
end

#start ⇒ Object

Returns the value of attribute start.



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# File 'lib/rutile/nfa.rb', line 67

def start
  @start
end

Class Method Details

.to_nfa(regex_raw, value) ⇒ Object 



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# File 'lib/rutile/nfa.rb', line 206

def self::to_nfa(regex_raw, value)
    regex_raw = regex_raw.chars
    regex = []
    brackets = false
    while (!regex_raw.empty?)
        char = regex_raw.shift
        if brackets
            case char
            when "]"
                regex << :clb
                brackets = false
            when "\\"
                ch = regex_raw.shift
                case ch
                when 'd'
                    regex += "1234567890".chars
                when 'a'
                    regex += "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".chars
                when 'w'
                    regex += " \t".chars
                else
                    regex << ch
                end
            else
                regex << char
            end
        else
            case char
            when "."
                regex << :dot
            when "("
                regex << :opp
            when ")"
                regex << :clp
            when "*"
                regex << :ast
            when "+"
                regex << :plu
            when "?"
                regex << :que
            when "["
                brackets = true
                regex << :opb
            when "|"
                regex << :pip
            when "\\"
                regex << regex_raw.shift
            else
                regex << char
            end
        end
    end
    
    ret = create_nfa(regex)
    
    if (regex != [])
        throw Exception.new "malformed regex."
    end
    
    ret.set_val value
    
    return ret
end

Instance Method Details

#and(a) ⇒ Object 



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# File 'lib/rutile/nfa.rb', line 110

def and a
    a.nodes.each {|node| node.update_pos @nodes.size}
    @nodes[@end].add("", a.start + @nodes.size)
    @end = a.end + @nodes.size
    @nodes += a.nodes
end

#asterix ⇒ Object 



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# File 'lib/rutile/nfa.rb', line 138

def asterix
    @nodes[@end].add("", @start)
    @nodes[@start].add("", @end)
end

#dup ⇒ Object 



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# File 'lib/rutile/nfa.rb', line 153

def dup
    dupl = NFA.new(dummy: true)
    
    dupl.nodes = (@nodes.map {|node| node.dup}).to_a
    dupl.start = @start
    dupl.end   = @end
    
    return dupl
end

#feed(char) ⇒ Object 



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# File 'lib/rutile/nfa.rb', line 96

def feed(char)
    move(char)
    finalize
    return val
end

#or(a) ⇒ Object 



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# File 'lib/rutile/nfa.rb', line 117

def or a
    total_size = a.nodes.size + @nodes.size
    new_start = Node.new(total_size)
    new_end = Node.new(total_size + 1)
    
    a.nodes.each {|node| node.update_pos @nodes.size}
    
    new_start.add("",@start)
    new_start.add("",a.start + @nodes.size)
    
    @nodes[@end].add("", new_end.pos)
    a.nodes[a.end].add("", new_end.pos)
    
    @nodes += a.nodes
    @nodes += [new_start, new_end]
    
    
    @start = new_start.pos
    @end   = new_end.pos
end

#plus ⇒ Object 



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# File 'lib/rutile/nfa.rb', line 147

def plus
    clone = self.dup
    clone.asterix
    self.and(clone)
end

#question ⇒ Object 



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# File 'lib/rutile/nfa.rb', line 143

def question
    @nodes[@start].add("", @end)
end

#reset ⇒ Object 



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# File 'lib/rutile/nfa.rb', line 102

def reset
    @new_stack = []
    @old_stack = []
    e_closure(@start)
    finalize
    return val
end

#set_val(value) ⇒ Object 



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# File 'lib/rutile/nfa.rb', line 163

def set_val value
    @nodes[@end].value = value
end

#val ⇒ Object 



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# File 'lib/rutile/nfa.rb', line 168

def val
    return @old_stack.map do |ind| 
        @nodes[ind].value
    end.to_a.uniq
end