diff options
Diffstat (limited to 'src/Language/GraphQL/AST/Lexer.hs')
| -rw-r--r-- | src/Language/GraphQL/AST/Lexer.hs | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/src/Language/GraphQL/AST/Lexer.hs b/src/Language/GraphQL/AST/Lexer.hs index e119303..0ba55e3 100644 --- a/src/Language/GraphQL/AST/Lexer.hs +++ b/src/Language/GraphQL/AST/Lexer.hs @@ -33,9 +33,12 @@ import Control.Applicative (Alternative(..), liftA2) import Data.Char (chr, digitToInt, isAsciiLower, isAsciiUpper, ord) import Data.Foldable (foldl') import Data.List (dropWhileEnd) +import qualified Data.List.NonEmpty as NonEmpty +import Data.List.NonEmpty (NonEmpty(..)) import Data.Proxy (Proxy(..)) import Data.Void (Void) import Text.Megaparsec ( Parsec + , (<?>) , between , chunk , chunkToTokens @@ -220,5 +223,14 @@ unicodeBOM :: Parser () unicodeBOM = optional (char '\xfeff') >> pure () -- | Parses "extend" followed by a 'symbol'. It is used by schema extensions. -extend :: Text -> Parser () -extend token = symbol "extend" *> symbol token >> pure () +extend :: forall a. Text -> String -> NonEmpty (Parser a) -> Parser a +extend token extensionLabel parsers + = foldr combine headParser (NonEmpty.tail parsers) + <?> extensionLabel + where + headParser = tryExtension $ NonEmpty.head parsers + combine current accumulated = accumulated <|> tryExtension current + tryExtension extensionParser = try + $ symbol "extend" + *> symbol token + *> extensionParser
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