src/TSN/Codegen.hs

   1 module TSN.Codegen (
   2   tsn_codegen_config,
   3   tsn_db_field_namer -- Used in a TSN.XML.News test.
   4   )
   5 where
   6
   7 import Data.Char ( toLower, toUpper )
   8 import Data.List.Utils ( join, split )
   9 import Database.Groundhog.TH (
  10   CodegenConfig ( namingStyle ),
  11   NamingStyle ( mkDbConstrName, mkDbFieldName, mkExprFieldName ),
  12   defaultCodegenConfig,
  13   lowerCaseSuffixNamingStyle )
  14
  15 -- | The lowercase naming style for database entities, provided by
  16 --   Groundhog. Makes a better starting point than the default.
  17 --
  18 lowercase_ns :: NamingStyle
  19 lowercase_ns = lowerCaseSuffixNamingStyle
  20
  21 -- | A database field name creator. It takes the field name (from a
  22 --   record type) and drops the first component determined by
  23 --   underscores. So, foo_bar_baz would get mapped to bar_baz in the
  24 --   database.
  25 tsn_db_field_namer :: String -> String -> Int -> String -> Int -> String
  26 tsn_db_field_namer _ _ _ fieldname _ =
  27   (join "_") . tail . (split "_") $ fieldname
  28
  29 tsn_expr_field_namer :: String -> String -> Int -> String -> Int -> String
  30 tsn_expr_field_namer _ _ _ fieldname _ =
  31   (join "_") . (map capitalize) . (split "_") $ fieldname
  32   where
  33     capitalize [] = []
  34     capitalize (c:cs) = (toUpper c : cs)
  35
  36 tsn_naming_style :: NamingStyle
  37 tsn_naming_style = lowercase_ns { mkDbFieldName = tsn_db_field_namer,
  38                                   mkExprFieldName = tsn_expr_field_namer }
  39
  40 tsn_codegen_config :: CodegenConfig
  41 tsn_codegen_config =
  42   defaultCodegenConfig { namingStyle = tsn_naming_style }