Merge pull request #339 from github/compile-python-class-definitions

Compile class definitions.

semantic-python/src/Language/Python/Core.hs

@@ -1,6 +1,6 @@
 {-# LANGUAGE ConstraintKinds, DataKinds, DefaultSignatures, DisambiguateRecordFields, FlexibleContexts,
              GeneralizedNewtypeDeriving, KindSignatures, LambdaCase, NamedFieldPuns, OverloadedLists,
-             PatternSynonyms, StandaloneDeriving, TypeApplications, TypeOperators, ViewPatterns #-}
+             OverloadedStrings, PatternSynonyms, StandaloneDeriving, TypeApplications, TypeOperators, ViewPatterns #-}
 
 module Language.Python.Core
 ( toplevelCompile
@@ -18,7 +18,7 @@ import           Core.Name as Name
 import           Data.Coerce
 import           Data.Foldable
 import           Data.Function
-import           Data.List.NonEmpty  (NonEmpty (..))
+import           Data.List.NonEmpty (NonEmpty (..))
 import           GHC.Records
 import           Source.Span (Span)
 import           Syntax.Stack (Stack (..))
@@ -194,7 +194,22 @@ instance Compile Py.Call where
     locate it (func $$* args) & cc
   compile it _ _ = fail ("can't compile Call node with generator expression: " <> show it)
 
-instance Compile Py.ClassDefinition
+instance Compile Py.ClassDefinition where
+  compile it@Py.ClassDefinition { body = pybody, name = Py.Identifier _ann (Name -> n) } cc next = do
+    let buildTypeCall _ = do
+          bindings <- asks @Bindings (toList . unBindings)
+          let buildName n = (n, pure n)
+              contents = record . fmap buildName $ bindings
+              typefn = pure "__semantic_prelude" ... "type"
+              object = pure "__semantic_prelude" ... "object"
+
+          pure (typefn $$ Core.string (coerce n) $$ object $$ contents)
+
+    body <- compile pybody buildTypeCall next
+    let assignClass = Name.named' n :<- body
+    let continuing = fmap (locate it . (assignClass >>>=))
+    continuing (local (def n) (cc next))
+
 instance Compile Py.ComparisonOperator
 
 deriving instance Compile Py.CompoundStatement

semantic-python/src/Prelude.score

@@ -0,0 +1,8 @@
+{
+  type <- \name -> \bases -> \dict ->
+    #record { __name: name, __bases: bases, __dict: dict };
+
+  object <- type "object" #unit #record{};
+
+  #record { type: type, object: object }
+}

semantic-python/test/Test.hs

@@ -12,6 +12,7 @@ import           Control.Monad.Catch
 import           Control.Monad.IO.Class
 import           Control.Monad.Trans.Resource (ResourceT, runResourceT)
 import           Core.Core
+import qualified Core.Parser
 import           Core.Pretty
 import qualified Core.Eval as Eval
 import           Core.Name
@@ -38,6 +39,7 @@ import qualified System.Path as Path
 import qualified System.Path.Directory as Path
 import           System.Path ((</>))
 import           Text.Show.Pretty (ppShow)
+import qualified Text.Trifecta as Trifecta
 import qualified TreeSitter.Python as TSP
 import qualified TreeSitter.Unmarshal as TS
 
@@ -50,12 +52,20 @@ import           Instances ()
 
 assertJQExpressionSucceeds :: Show a => Directive.Directive -> a -> Term (Ann Span :+: Core) Name -> HUnit.Assertion
 assertJQExpressionSucceeds directive tree core = do
-  bod <- case scopeGraph Eval.eval [File (Path.absRel "<interactive>") (Span (Pos 1 1) (Pos 1 1)) core] of
+  preludesrc <- ByteString.readFile "semantic-python/src/Prelude.score"
+  let ePrelude = Trifecta.parseByteString (Core.Parser.core <* Trifecta.eof) mempty preludesrc
+  prelude <- case Trifecta.foldResult (Left . show) Right ePrelude of
+    Right r -> pure r
+    Left s -> HUnit.assertFailure ("Couldn't parse prelude: " <> s)
+
+  let allTogether = (named' "__semantic_prelude" :<- prelude) >>>= core
+
+  bod <- case scopeGraph Eval.eval [File (Path.absRel "<interactive>") (Span (Pos 1 1) (Pos 1 1)) allTogether] of
     (heap, [File _ _ (Right result)]) -> pure $ Aeson.object
       [ "scope" Aeson..= heap
       , "heap"  Aeson..= result
       ]
-    _other                       -> HUnit.assertFailure "Couldn't run scope dumping mechanism; this shouldn't happen"
+    other -> HUnit.assertFailure ("Couldn't run scope dumping mechanism: " <> showCore (stripAnnotations allTogether) <> "\n" <> show other)
 
   let ignore = ByteStream.effects . hoist ByteStream.effects
       sgJSON = ByteStream.fromLazy $ Aeson.encode bod

semantic-python/test/fixtures/1-01-empty-module.py

@@ -1,2 +1 @@
-# CHECK-JQ: .scope == {}
-# CHECK-JQ: .heap  == {}
+# CHECK-JQ: .scope | has("__semantic_prelude") # prelude should be present

semantic-python/test/fixtures/1-02-pass-statement.py

@@ -1,2 +1,2 @@
-# CHECK-JQ: .scope == {}
+# CHECK-JQ: .scope | has("__semantic_prelude")
 pass

semantic-python/test/fixtures/1-03-empty-tuple.py

@@ -1,3 +1,2 @@
-# CHECK-JQ: .scope == {}
 # CHECK-TREE: #record{}
 ()

semantic-python/test/fixtures/3-01-empty-class-definition.py

@@ -0,0 +1,3 @@
+# CHECK-TREE: { Foo <- __semantic_prelude.type "Foo" __semantic_prelude.object #record {}; #record { Foo: Foo }}
+class Foo():
+    pass

semantic-python/test/fixtures/3-02-defining-instance-method.py

@@ -0,0 +1,5 @@
+# CHECK-TREE: { Foo <- { identity <- \self -> \x -> x; __semantic_prelude.type "Foo" __semantic_prelude.object #record { identity: identity } }; #record { Foo: Foo } }
+
+class Foo():
+    def identity(self, x):
+        return x