Static, but instance, but static (#3764)

Adds the ability to write `Foo.method (Mk_Foo 123)` as a synonym of `(Mk_Foo 123).method` because Rust.

Author: kustosz

CHANGELOG.md

@@ -378,6 +378,7 @@
 - [Invalidate module's IR cache if imported module changed][3703]
 - [Don't rename imported Main module that only imports names][3710]
 - [Notify node status to the IDE][3729]
+- [Make instance methods callable like statics][3764]
 - [Distinguish static and instance methods][3740]
 - [By-type pattern matching][3742]
 - [Fix performance of method calls on polyglot arrays][3781]
@@ -431,6 +432,7 @@
 [3710]: https://github.com/enso-org/enso/pull/3710
 [3729]: https://github.com/enso-org/enso/pull/3729
 [3740]: https://github.com/enso-org/enso/pull/3740
+[3764]: https://github.com/enso-org/enso/pull/3764
 [3742]: https://github.com/enso-org/enso/pull/3742
 [3781]: https://github.com/enso-org/enso/pull/3781
 

engine/runtime/src/main/scala/org/enso/compiler/codegen/IrToTruffle.scala

@@ -1474,7 +1474,11 @@ class IrToTruffle(
 
             val argName = arg.getName
 
-            if (seenArgNames contains argName) {
+            if (
+              argName != Constants.Names.SELF_ARGUMENT && seenArgNames.contains(
+                argName
+              )
+            ) {
               throw new IllegalStateException(
                 s"A duplicate argument name, $argName, was found during codegen."
               )

engine/runtime/src/main/scala/org/enso/compiler/context/SuggestionBuilder.scala

@@ -74,14 +74,14 @@ final class SuggestionBuilder[A: IndexedSource](val source: A) {
 
             go(tree ++= tpSuggestions.map(Tree.Node(_, Vector())), scope)
 
-          case IR.Module.Scope.Definition.Method
+          case m @ IR.Module.Scope.Definition.Method
                 .Explicit(
                   IR.Name.MethodReference(typePtr, methodName, _, _, _),
                   IR.Function.Lambda(args, body, _, _, _, _),
                   _,
                   _,
                   _
-                ) =>
+                ) if !m.isStaticWrapperForInstanceMethod =>
             val typeSignature = ir.getMetadata(TypeSignatures)
             val selfTypeOpt = typePtr match {
               case Some(typePtr) =>

engine/runtime/src/main/scala/org/enso/compiler/core/IR.scala

@@ -1455,6 +1455,21 @@ object IR {
                 true // if it's not a function, it has no arguments, therefore no `self`
             }
 
+            def isStaticWrapperForInstanceMethod: Boolean = body match {
+              case function: Function.Lambda =>
+                function.arguments.map(_.name) match {
+                  case IR.Name.Self(_, true, _, _) :: IR.Name.Self(
+                        _,
+                        false,
+                        _,
+                        _
+                      ) :: _ =>
+                    true
+                  case _ => false
+                }
+              case _ => false
+            }
+
           }
 
           /** The definition of a method for a given constructor using sugared

engine/runtime/src/main/scala/org/enso/compiler/pass/resolve/MethodDefinitions.scala

@@ -4,6 +4,7 @@ import org.enso.compiler.context.{InlineContext, ModuleContext}
 import org.enso.compiler.core.IR
 import org.enso.compiler.core.ir.MetadataStorage.ToPair
 import org.enso.compiler.data.BindingsMap
+import org.enso.compiler.data.BindingsMap.{Resolution, ResolvedType}
 import org.enso.compiler.exception.CompilerError
 import org.enso.compiler.pass.IRPass
 import org.enso.compiler.pass.analyse.BindingAnalysis
@@ -84,7 +85,38 @@ case object MethodDefinitions extends IRPass {
       case other => other
     }
 
-    ir.copy(bindings = newDefs)
+    val withStaticAliases = newDefs.flatMap {
+      case method: IR.Module.Scope.Definition.Method.Explicit
+          if !method.isStatic =>
+        method.methodReference.typePointer.flatMap(
+          _.getMetadata(this)
+        ) match {
+          case Some(Resolution(ResolvedType(_, tp))) if tp.members.nonEmpty =>
+            val dup = method.duplicate()
+            val static = dup.copy(body =
+              IR.Function.Lambda(
+                List(
+                  IR.DefinitionArgument
+                    .Specified(
+                      IR.Name.Self(None, true),
+                      None,
+                      None,
+                      false,
+                      None
+                    )
+                ),
+                dup.body,
+                None
+              )
+            )
+            List(method, static)
+          case _ => List(method)
+        }
+
+      case other => List(other)
+    }
+
+    ir.copy(bindings = withStaticAliases)
   }
 
   private def resolveType(

engine/runtime/src/main/scala/org/enso/compiler/pass/resolve/OverloadsResolution.scala

@@ -47,8 +47,8 @@ case object OverloadsResolution extends IRPass {
     ir: IR.Module,
     @unused moduleContext: ModuleContext
   ): IR.Module = {
-    var seenTypes: Set[String]                        = Set()
-    var seenMethods: Map[Option[String], Set[String]] = Map()
+    var seenTypes: Set[String]                                   = Set()
+    var seenMethods: Map[Option[String], Set[(String, Boolean)]] = Map()
 
     val types = ir.bindings.collect {
       case tp: IR.Module.Scope.Definition.Type => tp
@@ -72,7 +72,7 @@ case object OverloadsResolution extends IRPass {
     val newMethods: List[IR.Module.Scope.Definition] = methods.map(method => {
       if (
         seenMethods(method.typeName.map(_.name))
-          .contains(method.methodName.name)
+          .contains((method.methodName.name, method.isStatic))
       ) {
         IR.Error.Redefined
           .Method(method.typeName, method.methodName, method.location)
@@ -85,10 +85,10 @@ case object OverloadsResolution extends IRPass {
               method.location
             )
           case _ =>
-            val currentMethods = seenMethods(method.typeName.map(_.name))
+            val currentMethods: Set[(String, Boolean)] =
+              seenMethods(method.typeName.map(_.name))
             seenMethods = seenMethods + (method.typeName.map(_.name) ->
-            (currentMethods + method.methodName.name))
-
+            (currentMethods + ((method.methodName.name, method.isStatic))))
             method
         }
       }

engine/runtime/src/test/scala/org/enso/interpreter/test/semantic/MethodsTest.scala

@@ -165,19 +165,25 @@ class MethodsTest extends InterpreterTest {
       eval(code).toString shouldEqual "(Mk_Foo 123)"
     }
 
-    "not be callable on types when non-static" in {
+    "be callable on types when non-static, with additional self arg" in {
       val code =
-        """
+        """from Standard.Base.IO import all
+          |
           |type Foo
           |    Mk_Foo a
           |
-          |    inc self = Mk_Foo self.a
+          |    inc self = Foo.Mk_Foo self.a+1
           |
-          |main = Foo.inc
+          |main = 
+          |    IO.println (Foo.inc (Foo.Mk_Foo 12))
+          |    IO.println (Foo.Mk_Foo 13).inc
+          |    IO.println (.inc self=Foo self=(Foo.Mk_Foo 14))
+          |    IO.println (Foo.inc self=(Foo.Mk_Foo 15))
           |""".stripMargin
-      the[InterpreterException] thrownBy eval(
-        code
-      ) should have message "Method `inc` of Foo could not be found."
+      eval(code)
+      consumeOut.shouldEqual(
+        List("(Mk_Foo 13)", "(Mk_Foo 14)", "(Mk_Foo 15)", "(Mk_Foo 16)")
+      )
     }
 
     "not be callable on instances when static" in {