feat: Add support for animations

Signed-off-by: George Thomas <[email protected]>

flake.nix

@@ -415,6 +415,8 @@
                     # https://github.com/input-output-hk/haskell.nix/issues/1242
                     packages.mtl-compat.writeHieFiles = false;
                     packages.bytestring-builder.writeHieFiles = false;
+                    packages.fail.writeHieFiles = false;
+                    packages.diagrams.writeHieFiles = false;
                   }
                   {
                     #TODO This shouldn't be necessary - see the commented-out `build-tool-depends` in primer.cabal.

primer-service/test/outputs/OpenAPI/openapi.json

@@ -628,6 +628,24 @@
                             "contents"
                         ],
                         "type": "object"
+                    },
+                    {
+                        "properties": {
+                            "contents": {
+                                "type": "string"
+                            },
+                            "tag": {
+                                "enum": [
+                                    "PrimAnimation"
+                                ],
+                                "type": "string"
+                            }
+                        },
+                        "required": [
+                            "tag",
+                            "contents"
+                        ],
+                        "type": "object"
                     }
                 ]
             },

primer/gen/Primer/Gen/Core/Raw.hs

@@ -165,6 +165,7 @@ genPrimCon =
     _ = \case
       PrimChar _ -> ()
       PrimInt _ -> ()
+      PrimAnimation _ -> ()
 
 genType :: ExprGen Type
 genType =

primer/gen/Primer/Gen/Core/Typed.hs

@@ -487,7 +487,7 @@ genChk ty = do
             brs0 <- Gen.list (Range.linear 0 5) $ do
               p <- pg
               (p,) . CaseBranch (PatPrim p) [] <$> genChk ty
-            let brs = nubSortOn ((\case PrimInt n -> Left n; PrimChar c -> Right c) . fst) brs0
+            let brs = nubSortOn ((\case PrimInt n -> Left (Left n); PrimChar c -> Left (Right c); PrimAnimation b -> Right b) . fst) brs0
             fb <- genChk ty
             pure $ Case () e (snd <$> brs) (CaseFallback fb)
 
@@ -676,6 +676,7 @@ genPrimCon = catMaybes <$> sequence [whenInScope PrimChar 'a' genChar, whenInSco
     _ = \case
       PrimChar _ -> ()
       PrimInt _ -> ()
+      PrimAnimation _ -> ()
 
 -- We bias the distribution towards a small set, to make it more likely we
 -- generate name clashes on occasion

primer/primer.cabal

@@ -23,6 +23,7 @@ library
     Primer.App.Utils
     Primer.Builtins
     Primer.Builtins.DSL
+    Primer.Builtins.Picture
     Primer.Core
     Primer.Core.DSL
     Primer.Core.Meta
@@ -109,8 +110,11 @@ library
     , aeson                        >=2.0     && <2.2
     , assoc                        ^>=1.1
     , base                         >=4.12    && <4.19
+    , base64-bytestring            ^>=1.2.1
     , containers                   >=0.6.0.1 && <0.7.0
     , deriving-aeson               >=0.2     && <0.3.0
+    , diagrams-lib                 ^>=1.4.6
+    , diagrams-rasterific          ^>=1.4.2
     , exceptions                   >=0.10.4  && <0.11.0
     , extra                        >=1.7.10  && <1.8.0
     , generic-optics               >=2.0     && <2.3.0

primer/src/Primer/Builtins.hs

@@ -27,6 +27,14 @@ module Primer.Builtins (
   cRight,
   eitherDef,
   builtinModuleName,
+  tPicture,
+  cCircle,
+  cRect,
+  cColour,
+  cRotate,
+  cTranslate,
+  cCompoundPicture,
+  pictureDef,
 ) where
 
 import Primer.Core.Meta (
@@ -50,6 +58,21 @@ builtinModuleName = mkSimpleModuleName "Builtins"
 builtin :: Name -> GlobalName k
 builtin = qualifyName builtinModuleName
 
+tPicture :: TyConName
+tPicture = builtin "Picture"
+cCircle :: ValConName
+cCircle = builtin "Circle"
+cRect :: ValConName
+cRect = builtin "Rectangle"
+cColour :: ValConName
+cColour = builtin "Colour"
+cRotate :: ValConName
+cRotate = builtin "Rotate"
+cTranslate :: ValConName
+cTranslate = builtin "Translate"
+cCompoundPicture :: ValConName
+cCompoundPicture = builtin "Compound"
+
 tBool :: TyConName
 tBool = builtin "Bool"
 cTrue, cFalse :: ValConName
@@ -151,3 +174,23 @@ eitherDef =
     , astTypeDefConstructors = [ValCon cLeft [TVar () "a"], ValCon cRight [TVar () "b"]]
     , astTypeDefNameHints = []
     }
+
+pictureDef :: ASTTypeDef () ()
+pictureDef =
+  ASTTypeDef
+    { astTypeDefParameters = []
+    , astTypeDefConstructors =
+        [ ValCon cCircle [TCon () tInt]
+        , ValCon cRect [TCon () tInt, TCon () tInt]
+        , ValCon cColour [TCon () tInt, TCon () tInt, TCon () tInt, TCon () tPicture]
+        , ValCon cRotate [TCon () tInt, TCon () tPicture]
+        , ValCon cTranslate [TCon () tInt, TCon () tInt, TCon () tPicture]
+        , -- Pictures are ordered foreground to background, i.e. those earlier in the list appear on top.
+          ValCon cCompoundPicture [TApp () (TCon () tList) (TCon () tPicture)]
+        ]
+    , astTypeDefNameHints = []
+    }
+  where
+    -- TODO This can't currently be imported due to cyclic module issues.
+    tInt :: TyConName
+    tInt = qualifyName (mkSimpleModuleName "Primitives") "Int"

primer/src/Primer/Builtins/Picture.hs

@@ -0,0 +1,55 @@
+{-# LANGUAGE ViewPatterns #-}
+
+-- | A Haskell model of our built-in `Picture` type.
+-- Using this type can make working with pictures more convenient,
+-- including by giving us compile-time exhaustiveness checks.
+module Primer.Builtins.Picture (Picture (..), exprToPicture) where
+
+import Foreword
+
+import Primer.Builtins (
+  cCircle,
+  cColour,
+  cCompoundPicture,
+  cCons,
+  cNil,
+  cRect,
+  cRotate,
+  cTranslate,
+ )
+import Primer.Core (Expr' (..), PrimCon (..))
+
+data Picture
+  = Circle Integer
+  | Rect Integer Integer
+  | Colour Integer Integer Integer Picture
+  | Rotate Integer Picture
+  | Translate Integer Integer Picture
+  | CompoundPicture [Picture]
+
+exprToPicture :: Expr' a b c -> Maybe Picture
+exprToPicture = \case
+  Con _ c [PrimCon _ (PrimInt r)]
+    | c == cCircle ->
+        Just $ Circle r
+  Con _ c [PrimCon _ (PrimInt w), PrimCon _ (PrimInt h)]
+    | c == cRect ->
+        Just $ Rect w h
+  Con _ c [PrimCon _ (PrimInt r), PrimCon _ (PrimInt g), PrimCon _ (PrimInt b), exprToPicture -> Just p]
+    | c == cColour ->
+        Just $ Colour r g b p
+  Con _ c [PrimCon _ (PrimInt a), exprToPicture -> Just p]
+    | c == cRotate ->
+        Just $ Rotate a p
+  Con _ c [PrimCon _ (PrimInt x), PrimCon _ (PrimInt y), exprToPicture -> Just p]
+    | c == cTranslate ->
+        Just $ Translate x y p
+  Con _ c [exprToList -> Just (traverse exprToPicture -> Just ps)]
+    | c == cCompoundPicture ->
+        Just $ CompoundPicture ps
+  _ -> Nothing
+  where
+    exprToList = \case
+      Con _ c [] | c == cNil -> Just []
+      Con _ c [x, exprToList -> Just xs] | c == cCons -> Just $ x : xs
+      _ -> Nothing

primer/src/Primer/Core/Meta.hs

@@ -195,6 +195,8 @@ instance HasMetadata (Meta a) where
 data PrimCon
   = PrimChar Char
   | PrimInt Integer
+  | -- | Contains a base-64 encoding of an animated GIF.
+    PrimAnimation Text
   deriving stock (Eq, Show, Read, Data, Generic)
   deriving (FromJSON, ToJSON) via PrimerJSON PrimCon
   deriving anyclass (NFData)

primer/src/Primer/Module.hs

@@ -32,12 +32,14 @@ import Primer.Builtins (
   maybeDef,
   natDef,
   pairDef,
+  pictureDef,
   tBool,
   tEither,
   tList,
   tMaybe,
   tNat,
   tPair,
+  tPicture,
  )
 import Primer.Core (
   GVarName,
@@ -148,6 +150,7 @@ builtinModule = do
   maybeDef' <- generateTypeDefIDs $ TypeDefAST maybeDef
   pairDef' <- generateTypeDefIDs $ TypeDefAST pairDef
   eitherDef' <- generateTypeDefIDs $ TypeDefAST eitherDef
+  pictureDef' <- generateTypeDefIDs $ TypeDefAST pictureDef
   pure
     $ Module
       { moduleName = builtinModuleName
@@ -159,6 +162,7 @@ builtinModule = do
             , (baseName tMaybe, maybeDef')
             , (baseName tPair, pairDef')
             , (baseName tEither, eitherDef')
+            , (baseName tPicture, pictureDef')
             ]
       , moduleDefs = mempty
       }

primer/src/Primer/Pretty.hs

@@ -185,6 +185,7 @@ prettyExpr opts = \case
     prim = \case
       PrimChar c -> "Char" <+> pretty @Text (show c)
       PrimInt n -> "Int" <+> pretty @Text (show n)
+      PrimGlossProg n -> pretty @Text (show n)
     typeann e t = brac Round Yellow (pE e) <+> col Yellow "::" <> line <> brac Round Yellow (pT t)
 
 -- When grouped: " x "