class RbParser

# File lib/rbparser.rb, line 13
def initialize(s)

  super()
  params = {}
  expressions(@params)

  @to_a = scan_lines s
end

# File lib/rbparser.rb, line 24
def expressions(params) 
  
  parse /#(.*)/ do |comment|
    [:comment, comment]
  end    

  parse /if (.*) then/ do |condtn|
    [:if, condtn]
  end

  parse /class\s+(\w+)/ do |clssnme|
    [:class, clssnme]
  end

  parse /end/ do
    [:end]
  end

  parse /def\s+(\w+)\s*\((?:\)|([^\)]+)\))/ do |mthdnme, argslst|      
    r = [:def, mthdnme]
    r << argslst if argslst
    r
  end

  parse /(\w+)\(([^\)]+)\)/ do |mthdnme, argslst|
    [:method, mthdnme, argslst]
  end
  
  parse /case\s+(\w+)/ do |arg|
    [:case, arg]
  end

  parse /when\s+(.*)/ do |expression|
    [:when, expression]
  end
  
  parse /else/ do 
    [:else]
  end   

  parse /elsif\s+(.*)/ do |cndtn|
    [:elsif, cndtn]
  end

  parse /(\w+)\s+([^\)]+)\s+/ do |mthdnme, argslst|
    [:method, mthdnme, argslst]
  end    
  
  parse /.*/ do
    [:blankline]
  end
end

# File lib/rbparser.rb, line 81
def scan_lines(s)

  a = s.lines.inject([]) do |r,line|
    #puts 'line: ' + line.inspect
    line.strip.length > 0 ? r << scan_line(line) : r << [:blankline]

  end
  #puts 'a: ' + a.inspect
  treeize a
end

# File lib/rbparser.rb, line 92
def treeize(a)

  r = []

  while a.length > 0 do

    id, *remaining = stmnt = a.shift

    case id
    when :class

      name, baseclass = remaining
      r << [:class, name]
      r.last.concat treeize(a)

    when :def

      name, *args = remaining
      r << [:def, name.to_sym, args]
      r.last.concat treeize(a)

    when :case

      expr = remaining.first
      r << [:case, expr]
      r.last.concat treeize(a)

    when :when

      expr = remaining.first
      r << [:when, expr]        
      
    when :method
      
      name, *args = remaining
      r << [:method_call, name.to_sym, args]

    when :end

     return r
     
    when :comment
      r << [:comment, remaining.join]
      
    when :blankline then r << [:blankline]

    end

  end

  r
end