class Sexpistol::Parser

Constants

FLOAT
INTEGER
PARANTHESES
STRING
SYMBOL

Public Class Methods

new(string, parse_ruby_keyword_literals = false) click to toggle source
Calls superclass method
# File lib/sexpistol/parser.rb, line 13
def initialize(string, parse_ruby_keyword_literals = false)
  raise 'String given is not an s-expression' if string.strip[0] != '('
  raise 'Invalid s-expression' if string.count('(') != string.count(')')

  @parse_ruby_keyword_literals = parse_ruby_keyword_literals

  super(string.strip)
end

Public Instance Methods

convert_ruby_keyword_literals(token) click to toggle source
# File lib/sexpistol/parser.rb, line 51
def convert_ruby_keyword_literals(token)
  return token unless @parse_ruby_keyword_literals && token.is_a?(Symbol)

  case token
  when :nil then nil
  when :true then true
  when :false then false
  else token
  end
end
fetch_token() click to toggle source
# File lib/sexpistol/parser.rb, line 39
def fetch_token
  skip(/\s+/)

  return matched        if scan(PARANTHESES)
  return matched.undump if scan(STRING)
  return matched.to_f   if scan(FLOAT)
  return matched.to_i   if scan(INTEGER)
  return matched.to_sym if scan(SYMBOL)

  raise "Invalid token at position #{pos} near '#{scan(/.{0,20}/)}'."
end
parse(level = 0, exp = []) click to toggle source
# File lib/sexpistol/parser.rb, line 22
def parse(level = 0, exp = [])
  until eos?
    case token = fetch_token
    when ')' then break
    when '(' then exp << parse(level + 1)
    when String, Integer, Float, Symbol then exp << convert_ruby_keyword_literals(token)
    end
  end

  if level.zero?
    exp = exp.first if exp.first.is_a?(Array) && exp.length == 1
    exp = Sexpistol::SExpressionArray.new(exp) if exp.all? { |item| item.is_a?(Array) }
  end

  exp
end