improve naming

_plugins/sort_edtf.rb

@@ -1,20 +1,37 @@
 module Jekyll
   module SortEDTF
-    def clean_date_string(str)
+    def sort_edtf(array_of_strings)
+      non_empty_dates = array_of_strings.reject { |str| str.strip.empty? }
+
+      processed_dates = non_empty_dates.map do |str|
+      normalized_date_str = replace_x_with_parsable_0(str)
+      date_as_integer = normalize_to_integer(normalized_date_str)
+      display_format = create_display_format(str)
+
+      { numeric: date_as_integer, original: str, display_format: display_format }
+      end
+
+      sorted_dates = processed_dates.sort_by { |date| -date[:numeric] }
+      sorted_dates.map { |date| "#{date[:display_format]}:#{date[:original]}" }
+    end
+
+    private
+
+    def replace_x_with_parsable_0(str)
       str.gsub(/[Xu]/, '0')
     end
 
-    def compute_numeric_value(cleaned_str)
-      numeric_str = if cleaned_str.start_with?('-')
-                         cleaned_str.sub(/^-0+/, '-')
+    def normalize_to_integer(year_str)
+      numeric_str = if year_str.start_with?('-')
+                        year_str.sub(/^-0+/, '-')
                        else
-                         cleaned_str.sub(/^0+(?=\d)/, '')
+                        year_str.sub(/^0+(?=\d)/, '')
                        end
 
       if numeric_str.match?(/^-?\d+$/)
         numeric_str.to_i
       else
-        raise ArgumentError, "Invalid date format: #{cleaned_str}"
+        raise ArgumentError, "Invalid year format: #{year_str}"
       end
     end
 
@@ -26,20 +43,7 @@ def create_display_format(str)
       end
     end
 
-    def sort_edtf(array_of_strings)
-      valid_dates = array_of_strings.reject { |str| str.strip.empty? }
-
-      parsed_dates = valid_dates.map do |str|
-      cleaned_str = clean_date_string(str)
-      numeric_value = compute_numeric_value(cleaned_str)
-      display_format = create_display_format(str)
-
-      { numeric: numeric_value, original: str, display_format: display_format }
-      end
 
-      sorted_dates = parsed_dates.sort_by { |date| -date[:numeric] }
-      sorted_dates.map { |date| "#{date[:display_format]}:#{date[:original]}" }
-    end
   end
 end