reader.rb in dbf-0.3.0

- old
+ new

@@ -8,10 +8,13 @@
   DATE_REGEXP = /([\d]{4})([\d]{2})([\d]{2})/
   VERSION_DESCRIPTIONS = {"02" => "FoxBase", "03" => "dBase III without memo file", "04" => "dBase IV without memo file",
     "05" => "dBase V without memo file", "30" => "Visual FoxPro", "31" => "Visual FoxPro with AutoIncrement field",
     "7b" => "dBase IV with memo file", "83" => "dBase III with memo file", "8b" => "dBase IV with memo file",
     "8e" => "dBase IV with SQL table", "f5" => "FoxPro with memo file", "fb" => "FoxPro without memo file"}
+    
+  class DBFError < StandardError; end
+  class UnpackError < DBFError; end
   
   class Reader
     
     attr_reader :field_count
     attr_reader :fields
@@ -83,16 +86,16 @@
           else
             record[field.name] = unpack_float(field) rescue nil
           end
         when 'D' # date
           raw = unpack_string(field).to_s.strip
-          record[field.name] = raw.empty ? nil : Date.new(*raw.match(DATE_REGEXP).to_a.slice(1,3).map {|n| n.to_i}) rescue nil
+          record[field.name] = raw.empty? ? nil : Date.new(*raw.match(DATE_REGEXP).to_a.slice(1,3).map {|n| n.to_i}) rescue nil
         when 'M' # memo
           starting_block = unpack_integer(field)
           record[field.name] = starting_block == 0 ? nil : memo(starting_block) rescue nil
         when 'L' # logical
-          record[field.name] = unpack_string(field) =~ /(y|t)/i ? true : false rescue false
+          record[field.name] = unpack_string(field) =~ /^(y|t)$/i ? true : false rescue false
         else
           record[field.name] = unpack_string(field)
         end
       end
       record
@@ -119,12 +122,16 @@
     
     def seek_to_record(index)
       seek(@record_length * index)
     end
     
+    def unpack_field(field)
+      @data_file.read(field.length).unpack("a#{field.length}")
+    end
+    
     def unpack_string(field)
-      @data_file.read(field.length).unpack("a#{field.length}").to_s
+      unpack_field(field).to_s
     end
     
     def unpack_integer(field)
       unpack_string(field).to_i
     end
@@ -133,13 +140,16 @@
       unpack_string(field).to_f
     end
     
   end
   
+  class FieldError < StandardError; end
+  
   class Field
     attr_accessor :name, :type, :length, :decimal
 
     def initialize(name, type, length, decimal)
+      raise FieldError, "field length must be greater than 0" unless length > 0
       self.name, self.type, self.length, self.decimal = name, type, length, decimal
     end
 
     def name=(name)
       @name = name.gsub(/\0/, '')