NameList.hs

module PostgresqlSyntax.Ast.NameList where

import qualified HeadedMegaparsec as Parser
import PostgresqlSyntax.Ast.Ident
import qualified PostgresqlSyntax.Helpers.Gens as Gens
import qualified PostgresqlSyntax.Helpers.Parsers as Parsers
import qualified PostgresqlSyntax.Helpers.TextBuilders as TextBuilders
import PostgresqlSyntax.IsAst
import qualified PostgresqlSyntax.KeywordSet as KeywordSet
import PostgresqlSyntax.Prelude
import qualified Test.QuickCheck as Qc

-- |
-- ==== References
-- @
-- name_list:
--   | name
--   | name_list ',' name
-- @
--
-- 'Name' is a bare alias to 'PostgresqlSyntax.Ast.ColId' which is a bare
-- alias to 'Ident', but the @ColId@ /parser/ (kept in "PostgresqlSyntax.Parsing"
-- since @ColId@ itself isn't extracted in this batch) is more permissive
-- than plain 'Ident': it additionally accepts the @unreserved_keyword@ and
-- @col_name_keyword@ lexical classes as identifiers. Since this module sits
-- below "PostgresqlSyntax.Parsing" (no import cycle allowed), that
-- ColId-flavored element parser is duplicated here (mirroring @colId@'s
-- definition) rather than reused, to preserve exact parsing behavior.
newtype NameList = NameList (NonEmpty Ident)
  deriving (Show, Generic, Eq, Ord, Data)

instance IsAst NameList where
  toTextBuilder settings (NameList a) = TextBuilders.commaNonEmpty (toTextBuilder settings) a
  parser settings = NameList <$> Parsers.sep1 Parsers.commaSeparator colIdLikeName
    where
      colIdLikeName =
        Parser.label "identifier" $
          parser settings
            <|> Parsers.keywordNameFromSet UnquotedIdent (KeywordSet.unreservedKeyword <> KeywordSet.colNameKeyword)

instance Qc.Arbitrary NameList where
  shrink = Qc.genericShrink
  arbitrary = NameList <$> Gens.nonEmptyUpTo 7 Qc.arbitrary