From 44dc80bb37558fc6a35b22791ac407b63956176d Mon Sep 17 00:00:00 2001
From: Eugen Wissner <belka@caraus.de>
Date: Mon, 30 Dec 2019 18:26:24 +0100
Subject: Replace substitution function with a map

It makes using variables with queries more approachable, but some work
still has to be done.
- The type `Subs` should be renamed and moved out of `Schema`, together with
`AST.Core.Value` probably.
- Some kind of conversion should be possible from a user-defined input
type T to the Value. So the final HashMap should have a type like
`HashMap name a`, where a is an instance of a potential typeclass
InputType.
---
 src/Language/GraphQL/Execute/Transform.hs | 6 ++----
 src/Language/GraphQL/Schema.hs            | 5 +++--
 2 files changed, 5 insertions(+), 6 deletions(-)

(limited to 'src/Language/GraphQL')

diff --git a/src/Language/GraphQL/Execute/Transform.hs b/src/Language/GraphQL/Execute/Transform.hs
index 7c2e100..a85e451 100644
--- a/src/Language/GraphQL/Execute/Transform.hs
+++ b/src/Language/GraphQL/Execute/Transform.hs
@@ -11,7 +11,7 @@ module Language.GraphQL.Execute.Transform
 import Control.Arrow (first)
 import Control.Monad (foldM, unless)
 import Control.Monad.Trans.Class (lift)
-import Control.Monad.Trans.Reader (ReaderT, ask, runReaderT)
+import Control.Monad.Trans.Reader (ReaderT, asks, runReaderT)
 import Control.Monad.Trans.State (StateT, evalStateT, gets, modify)
 import Data.HashMap.Strict (HashMap)
 import qualified Data.HashMap.Strict as HashMap
@@ -155,9 +155,7 @@ argument :: Full.Argument -> TransformT Core.Argument
 argument (Full.Argument n v) = Core.Argument n <$> value v
 
 value :: Full.Value -> TransformT Core.Value
-value (Full.Variable n) = do
-    substitute' <- lift ask
-    lift . lift $ substitute' n
+value (Full.Variable name) = lift (asks $ HashMap.lookup name) >>= lift . lift
 value (Full.Int i) = pure $ Core.Int i
 value (Full.Float f) = pure $ Core.Float f
 value (Full.String x) = pure $ Core.String x
diff --git a/src/Language/GraphQL/Schema.hs b/src/Language/GraphQL/Schema.hs
index fa8bf78..facf722 100644
--- a/src/Language/GraphQL/Schema.hs
+++ b/src/Language/GraphQL/Schema.hs
@@ -44,8 +44,9 @@ data Resolver m = Resolver
     Text -- ^ Name
     (Field -> CollectErrsT m Aeson.Object) -- ^ Resolver
 
--- | Variable substitution function.
-type Subs = Name -> Maybe Value
+-- | Contains variables for the query. The key of the map is a variable name,
+--   and the value is the variable value.
+type Subs = HashMap Name Value
 
 -- | Create a new 'Resolver' with the given 'Name' from the given 'Resolver's.
 object :: MonadIO m => Name -> ActionT m [Resolver m] -> Resolver m
-- 
cgit v1.2.3