answers

parser.rb

@@ -0,0 +1,109 @@
+# read data in string
+
+class CSVParser
+  attr_reader :data, :current_row, :current_field, :position, :in_quotes,
+    :field_delimiter, :quote_delimiter, :string
+
+  def initialize(string, field_delimiter = ',', quote_delimiter = '"')
+    @data = []
+    @current_row = []
+    @current_field = ""
+    @string = string
+    @position = 0
+    @in_quotes = false
+    @field_delimiter = field_delimiter
+    @quote_delimiter = quote_delimiter
+  end
+
+  def parse
+    while position < string.length
+      consume_character
+    end
+
+    current_row << current_field unless current_field.empty?
+    data << current_row unless current_row.empty?
+
+    data
+  end
+
+  private
+
+  def consume_character
+    t = string[position]
+    if t == quote_delimiter
+      consume_quote
+    elsif !in_quotes && t == field_delimiter
+      current_row << current_field
+      @current_field = ""
+    elsif !in_quotes && t == "\n"
+      current_row  << current_field
+      data << current_row
+      puts current_row.inspect
+      @current_row = []
+      @current_field = ''
+    else
+      current_field << t
+    end
+    @position += 1
+  end
+
+  def consume_quote
+    if in_quotes
+      next_character = string[position + 1] rescue ''
+      if next_character == quote_delimiter
+        current_field << quote_delimiter
+        @position += 1
+      else
+        @in_quotes = false
+      end
+    else
+      @in_quotes = true
+    end
+  end
+end
+
+# def csv_parser(string,field_delimiter,quote_delimiter)
+#
+#   data = []
+#   current_row = []
+#   current_field = ""
+#   i = 0
+#   in_quotes = false
+#
+#   while i < string.length
+#     t = string[i]
+#     if t == quote_delimiter
+#       if in_quotes
+#         next_character = string[i + 1] rescue ''
+#         if next_character == quote_delimiter
+#           current_field << quote_delimiter
+#           i += 1
+#         else
+#           in_quotes = false
+#         end
+#       else
+#         in_quotes = true
+#       end
+#     elsif !in_quotes && t == field_delimiter
+#       current_row << current_field
+#       current_field = ""
+#     elsif !in_quotes && t == "\n"
+#       current_row  << current_field
+#       data << current_row
+#       puts current_row.inspect
+#       current_row = []
+#       current_field = ''
+#     else
+#       current_field << t
+#     end
+#     i = i + 1
+#   end
+#
+#   current_row << current_field unless current_field.empty?
+#   data << current_row unless current_row.empty?
+#
+#   data
+# end
+
+csv_data = File.read("cars.csv") ; csv_data.length
+puts CSVParser.new(csv_data).parse.inspect

states.txt

@@ -0,0 +1,3 @@
+no quotes
+"x" - quotes
+? - quotes