Class: Packcr::Node::AlternateNode

Inherits:
Packcr::Node show all
Defined in:
lib/packcr/node/alternate_node.rb,
lib/packcr/generated/node/alternate_node.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Packcr::Node

#link_references, #reversible?, #seq, #sequence?, #setup, #setup_rule

Constructor Details

#initialize(*nodes) ⇒ AlternateNode

Returns a new instance of AlternateNode.



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# File 'lib/packcr/node/alternate_node.rb', line 6

def initialize(*nodes)
  super()
  self.nodes = nodes
end

Instance Attribute Details

#nodes ⇒ Object

Returns the value of attribute nodes.



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# File 'lib/packcr/node/alternate_node.rb', line 4

def nodes
  @nodes
end

Instance Method Details

#alt(node) ⇒ Object 



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# File 'lib/packcr/node/alternate_node.rb', line 11

def alt(node)
  @nodes << node if node
  self
end

#debug_dump(indent = 0) ⇒ Object 



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# File 'lib/packcr/node/alternate_node.rb', line 16

def debug_dump(indent = 0)
  $stdout.print "#{" " * indent}Alternate(max:#{max}, len:#{nodes.length}) {\n"
  nodes.each do |node|
    node.debug_dump(indent + 2)
  end
  $stdout.print "#{" " * indent}}\n"
end

#generate_code(gen, onfail, indent, bare, oncut: nil) ⇒ Object 



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# File 'lib/packcr/node/alternate_node.rb', line 30

def generate_code(gen, onfail, indent, bare, oncut: nil)
  gen.write Packcr.format_code(get_code(gen, onfail, indent, bare, oncut), indent: indent, unwrap: bare)
end

#get_code(gen, onfail, indent, bare, oncut) ⇒ Object 



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# File 'lib/packcr/generated/node/alternate_node.rb', line 4

def get_code(gen, onfail, indent, bare, oncut)
  case gen.lang
  when :c
    erbout = +""
    m = gen.next_label
    erbout << "{\n    const size_t p = ctx->position_offset;\n".freeze

    if gen.location
      erbout << "    const packcr_location_t p_loc = ctx->position_offset_loc;\n".freeze
    end
    erbout << "    const size_t n = chunk->thunks.len;\n".freeze

    nodes.each_with_index do |expr, i|
      c = i + 1 < nodes.length
      l = gen.next_label
      r = expr.reachability

      erbout << "#{gen.generate_code(expr, l, 4, false)}".freeze
      case r
      when Packcr::CODE_REACH__ALWAYS_SUCCEED
        if c
          erbout << "    /* unreachable codes omitted */\n".freeze
        end
        break
      when Packcr::CODE_REACH__BOTH
        erbout << "    goto L#{format("%04d", m)};\n".freeze
      end
      erbout << "L#{format("%04d", l)}:;\n    ctx->position_offset = p;\n".freeze

      if gen.location
        erbout << "    ctx->position_offset_loc = p_loc;\n".freeze
      end
      erbout << "    packcr_thunk_array__revert(ctx->auxil, &chunk->thunks, n);\n".freeze

      next if c

      erbout << "    goto L#{format("%04d", onfail)};\n".freeze
    end
    erbout << "L#{format("%04d", m)}:;\n}\n".freeze

    erbout
  when :rb
    erbout = +""
    m = gen.next_label
    erbout << "catch(#{m}) do\n  pos#{gen.level} = @position_offset\n".freeze

    if gen.location
      erbout << "  p_loc#{gen.level} = @position_offset_loc\n".freeze
    end
    erbout << "  n#{gen.level} = answer.thunks.length\n".freeze

    nodes.each_with_index do |expr, i|
      c = i + 1 < nodes.length
      if expr.reversible?(gen)

        erbout << "#{gen.generate_code(expr, m, 2, false, reverse: true, oncut: onfail)}".freeze
      else
        l = gen.next_label
        erbout << "  catch(#{l}) do\n".freeze

        r = expr.reachability

        erbout << "#{gen.generate_code(expr, l, 4, false, oncut: onfail)}".freeze
        case r
        when Packcr::CODE_REACH__ALWAYS_SUCCEED
          if c
            erbout << "    # unreachable codes omitted\n".freeze
          end
          erbout << "  end\n".freeze

          break
        when Packcr::CODE_REACH__BOTH
          erbout << "    throw(#{m})\n".freeze
        end
        erbout << "  end\n".freeze
      end
      erbout << "  @position_offset = pos#{gen.level}\n".freeze

      if gen.location
        erbout << "  @position_offset_loc = p_loc#{gen.level}\n".freeze
      end
      erbout << "  answer.thunks[n#{gen.level}..-1] = []\n".freeze

      next if c

      erbout << "  throw(#{onfail})\n".freeze
    end
    erbout << "end\n".freeze

    erbout
  end
end

#max ⇒ Object 



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# File 'lib/packcr/node/alternate_node.rb', line 24

def max
  m = 1
  m <<= 1 while m < @nodes.length
  m
end

#reachability ⇒ Object 



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# File 'lib/packcr/node/alternate_node.rb', line 34

def reachability
  r = Packcr::CODE_REACH__ALWAYS_FAIL
  nodes.each do |expr|
    case expr.reachability
    when Packcr::CODE_REACH__ALWAYS_SUCCEED
      return Packcr::CODE_REACH__ALWAYS_SUCCEED
    when Packcr::CODE_REACH__BOTH
      r = Packcr::CODE_REACH__BOTH
    end
  end
  r
end

#to_h ⇒ Object 



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# File 'lib/packcr/node/alternate_node.rb', line 76

def to_h
  {
    type: :alternate,
    nodes: nodes&.map(&:to_h),
  }
end

#verify_captures(ctx, capts) ⇒ Object 



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# File 'lib/packcr/node/alternate_node.rb', line 64

def verify_captures(ctx, capts)
  m = capts.length
  v = capts.dup
  nodes.each do |node|
    v = v[0, m]
    node.verify_captures(ctx, v)
    v[m...-1].each do |added_node|
      capts.push(added_node)
    end
  end
end

#verify_variables(vars) ⇒ Object 



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# File 'lib/packcr/node/alternate_node.rb', line 47

def verify_variables(vars)
  m = vars.length
  v = vars.dup
  nodes.each do |node|
    v = v[0, m]
    node.verify_variables(v)
    v[m...-1].each do |added_node|
      found = vars[m...-1].any? do |added_var|
        added_node.index == added_var.index
      end
      if !found
        vars.push(added_node)
      end
    end
  end
end