Merge pull request #140 from OxfordAbstracts/variant-args

Allow `Variant`s as well as data type enums

src/GraphQL/Client/Args.purs

@@ -7,6 +7,7 @@ import Data.Bifunctor (class Bifunctor)
 import Data.Maybe (Maybe)
 import Data.Newtype (class Newtype)
 import Data.Symbol (class IsSymbol)
+import Data.Variant (Variant)
 import GraphQL.Client.Args.AllowedMismatch (AllowedMismatch)
 import GraphQL.Client.AsGql (AsGql)
 import GraphQL.Client.NullArray (NullArray)
@@ -70,7 +71,8 @@ class ArgGqlAt at params arg
 instance argAsGql :: ArgGqlAt at param arg => ArgGqlAt at (AsGql gqlName param) arg
 else instance argToGqlNotNull :: (IsNotNull at param arg, ArgGqlAt at param arg) => ArgGqlAt at (NotNull param) arg
 else instance argToGqlIgnore :: ArgGqlAt at param IgnoreArg
-else instance argVarJson :: ArgGqlAt at Json (Var sym Json) -- Json can only be used with a variable 
+else instance argToGqlVariant :: (Union r () params) => ArgGqlAt at (Variant params) (Variant r)
+else instance argVarJson :: ArgGqlAt at Json (Var sym Json) -- Json can only be used with a variable
 else instance argToGqlJsonNotAllowed :: TE.Fail (TE.Text "A `Json` query argument can only be used as a variable ") => ArgGqlAt at Json Json
 else instance argVar :: ArgGqlAt at param arg => ArgGqlAt at param (Var sym arg)
 else instance argToGqlArrayNull :: ArgGqlAt at (Array param) NullArray

src/GraphQL/Client/ToGqlString.purs

@@ -56,6 +56,7 @@ import Data.String.Regex.Flags (global)
 import Data.String.Regex.Unsafe (unsafeRegex)
 import Data.Symbol (class IsSymbol, reflectSymbol)
 import Data.Time (Time)
+import Data.Variant (Unvariant(..), Variant, unvariant)
 import Foreign (Foreign)
 import Foreign.Object (Object)
 import Foreign.Object as Object
@@ -317,6 +318,8 @@ else instance gqlArgStringErrorBoundary :: GqlArgString a => GqlArgString (Error
   toGqlArgStringImpl (ErrorBoundary a) = toGqlArgStringImpl a
 else instance gqlArgStringAllowedMismatch :: GqlArgString a => GqlArgString (AllowedMismatch t a) where
   toGqlArgStringImpl = unwrap >>> toGqlArgStringImpl
+else instance gqlargVariant :: GqlArgString (Variant r) where
+  toGqlArgStringImpl v = unvariant v # \(Unvariant f) -> f \p _ -> reflectSymbol p
 else instance gqlArgStringVar :: IsSymbol sym => GqlArgString (Var sym a) where
   toGqlArgStringImpl _ = "$" <> reflectSymbol (Proxy :: Proxy sym)
 else instance gqlArgStringOrArg ::