Class: Parser

Inherits:
Object
  • Object
show all
Includes:
Types
Defined in:
lib/rpl/parser.rb

Class Method Summary collapse

Methods included from Types

new_object

Class Method Details

.parse(input) ⇒ Object 



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# File 'lib/rpl/parser.rb', line 15

def self.parse( input )
  unless input.index("\n").nil?
    input = input.split("\n")
                 .map do |line|
      comment_begin_index = line.index('@')

      case comment_begin_index
      when nil
        line
      when 0
        ''
      else
        line[0..(comment_begin_index - 1)]
      end
    end
                 .join(' ')
  end

  splitted_input = input.split(' ')

  # 2-passes:
  # 1. regroup strings, lists, complexes, names and programs
  opened_programs = 0
  closed_programs = 0

  opened_lists = 0
  closed_lists = 0

  opened_complexes = 0
  closed_complexes = 0

  string_delimiters = 0

  name_delimiters = 0

  regrouping = false

  regrouped_input = []
  splitted_input.each do |elt|
    if elt[0] == '«'
      opened_programs += 1
      elt.gsub!( '«', '« ') if elt.length > 1 && elt[1] != ' '
    elsif elt[0] == '{'
      opened_lists += 1
      elt.gsub!( '{', '{ ') if elt.length > 1 && elt[1] != ' '
    elsif elt[0] == '('
      opened_complexes += 1
      elt.gsub!( '( ', '(') if elt.length > 1 && elt[1] == ' '
    elsif elt[0] == '"' && elt.length > 1
      string_delimiters += 1
    elsif elt[0] == "'" && elt.length > 1
      name_delimiters += 1
    end

    elt = "#{regrouped_input.pop}#{opened_complexes > closed_complexes ? '' : ' '}#{elt}".strip if regrouping

    regrouped_input << elt

    case elt[-1]
    when '»'
      closed_programs += 1
      elt.gsub!( '»', ' »') if elt.length > 1 && elt[-2] != ' '
    when '}'
      closed_lists += 1
      elt.gsub!( '}', ' }') if elt.length > 1 && elt[-2] != ' '
    when ')'
      closed_complexes += 1
      elt.gsub!( ' )', ')') if elt.length > 1 && elt[-2] == ' '
    when '"'
      string_delimiters += 1
    when "'"
      name_delimiters += 1
    end

    regrouping = string_delimiters.odd? || name_delimiters.odd? || (opened_programs > closed_programs) || (opened_lists > closed_lists) || (opened_complexes > closed_complexes)
  end

  # 2. parse
  parsed_input = regrouped_input.map do |element|
    if RplBoolean.can_parse?( element )
      Types.new_object( RplBoolean, element )
    elsif RplNumeric.can_parse?( element )
      Types.new_object( RplNumeric, element )
    elsif RplComplex.can_parse?( element )
      Types.new_object( RplComplex, element )
    elsif RplList.can_parse?( element )
      Types.new_object( RplList, element )
    elsif RplString.can_parse?( element )
      Types.new_object( RplString, element )
    elsif RplProgram.can_parse?( element )
      Types.new_object( RplProgram, element )
    elsif RplName.can_parse?( element )
      Types.new_object( RplName, element )
    end
  end

  parsed_input
end