Merge pull request #1002 from ScorexFoundation/v6.0-methodcall

[6.0]  Common SMethod and MethodCallSerializer new features

data/shared/src/main/scala/sigma/ast/SMethod.scala

@@ -50,31 +50,40 @@ case class MethodIRInfo(
 
 /** Represents method descriptor.
   *
-  * @param objType type or type constructor descriptor
-  * @param name    method name
-  * @param stype   method signature type,
-  *                where `stype.tDom`` - argument type and
-  *                `stype.tRange` - method result type.
-  * @param methodId method code, it should be unique among methods of the same objType.
-  * @param costKind cost descriptor for this method
-  * @param irInfo  meta information connecting SMethod with ErgoTree (see [[MethodIRInfo]])
-  * @param docInfo optional human readable method description data
-  * @param costFunc optional specification of how the cost should be computed for the
-  *                 given method call (See ErgoTreeEvaluator.calcCost method).
+  * @param objType         type or type constructor descriptor
+  * @param name            method name
+  * @param stype           method signature type,
+  *                        where `stype.tDom`` - argument type and
+  *                        `stype.tRange` - method result type.
+  * @param methodId        method code, it should be unique among methods of the same objType.
+  * @param costKind        cost descriptor for this method
+  * @param explicitTypeArgs list of type parameters which require explicit
+  *                        serialization in [[MethodCall]]s (i.e for deserialize[T], getVar[T], getReg[T])
+  * @param irInfo          meta information connecting SMethod with ErgoTree (see [[MethodIRInfo]])
+  * @param docInfo         optional human readable method description data
+  * @param costFunc        optional specification of how the cost should be computed for the
+  *                        given method call (See ErgoTreeEvaluator.calcCost method).
+  * @param userDefinedInvoke optional custom method evaluation function
   */
 case class SMethod(
     objType: MethodsContainer,
     name: String,
     stype: SFunc,
     methodId: Byte,
     costKind: CostKind,
+    explicitTypeArgs: Seq[STypeVar],
     irInfo: MethodIRInfo,
     docInfo: Option[OperationInfo],
-    costFunc: Option[MethodCostFunc]) {
+    costFunc: Option[MethodCostFunc],
+    userDefinedInvoke: Option[SMethod.InvokeHandler]
+) {
 
   /** Operation descriptor of this method. */
   lazy val opDesc = MethodDesc(this)
 
+  /** Return true if this method has runtime type parameters */
+  def hasExplicitTypeArgs: Boolean = explicitTypeArgs.nonEmpty
+
   /** Finds and keeps the [[RMethod]] instance which corresponds to this method descriptor.
     * The lazy value is forced only if irInfo.javaMethod == None
     */
@@ -106,7 +115,12 @@ case class SMethod(
   /** Invoke this method on the given object with the arguments.
     * This is used for methods with FixedCost costKind. */
   def invokeFixed(obj: Any, args: Array[Any]): Any = {
-    javaMethod.invoke(obj, args.asInstanceOf[Array[AnyRef]]:_*)
+    userDefinedInvoke match {
+      case Some(h) =>
+        h(this, obj, args)
+      case None =>
+        javaMethod.invoke(obj, args.asInstanceOf[Array[AnyRef]]:_*)
+    }
   }
 
   // TODO optimize: avoid lookup when this SMethod is created via `specializeFor`
@@ -146,6 +160,11 @@ case class SMethod(
     m
   }
 
+  /** Create a new instance with the given user-defined invoke handler. */
+  def withUserDefinedInvoke(handler: SMethod.InvokeHandler): SMethod = {
+    copy(userDefinedInvoke = Some(handler))
+  }
+
   /** Create a new instance with the given stype. */
   def withSType(newSType: SFunc): SMethod = copy(stype = newSType)
 
@@ -255,6 +274,12 @@ object SMethod {
     */
   type InvokeDescBuilder = SFunc => Seq[SType]
 
+  /** Type of user-defined function which is called to handle method invocation.
+    * Instances of this type can be attached to [[SMethod]] instances.
+    * @see SNumericTypeMethods.ToBytesMethod
+    */
+  type InvokeHandler = (SMethod, Any, Array[Any]) => Any
+
   /** Return [[Method]] descriptor for the given `methodName` on the given `cT` type.
     * @param methodName the name of the method to lookup
     * @param cT the class where to search the methodName
@@ -284,10 +309,12 @@ object SMethod {
   /** Convenience factory method. */
   def apply(objType: MethodsContainer, name: String, stype: SFunc,
       methodId: Byte,
-      costKind: CostKind): SMethod = {
+      costKind: CostKind,
+      explicitTypeArgs: Seq[STypeVar] = Nil
+  ): SMethod = {
     SMethod(
-      objType, name, stype, methodId, costKind,
-      MethodIRInfo(None, None, None), None, None)
+      objType, name, stype, methodId, costKind, explicitTypeArgs,
+      MethodIRInfo(None, None, None), None, None, None)
   }
 
 

data/shared/src/main/scala/sigma/serialization/MethodCallSerializer.scala

@@ -1,13 +1,15 @@
 package sigma.serialization
 
 import sigma.ast.syntax._
-import sigma.ast.{MethodCall, SContextMethods, SMethod, SType, STypeSubst, Value, ValueCompanion}
+import sigma.ast.{MethodCall, SContextMethods, SMethod, SType, STypeSubst, STypeVar, Value, ValueCompanion}
 import sigma.util.safeNewArray
 import SigmaByteWriter._
 import debox.cfor
 import sigma.ast.SContextMethods.BlockchainContextMethodNames
 import sigma.serialization.CoreByteWriter.{ArgInfo, DataInfo}
 
+import scala.collection.compat.immutable.ArraySeq
+
 case class MethodCallSerializer(cons: (Value[SType], SMethod, IndexedSeq[Value[SType]], STypeSubst) => Value[SType])
   extends ValueSerializer[MethodCall] {
   override def opDesc: ValueCompanion = MethodCall
@@ -23,6 +25,10 @@ case class MethodCallSerializer(cons: (Value[SType], SMethod, IndexedSeq[Value[S
     w.putValue(mc.obj, objInfo)
     assert(mc.args.nonEmpty)
     w.putValues(mc.args, argsInfo, argsItemInfo)
+    mc.method.explicitTypeArgs.foreach { a =>
+      val tpe = mc.typeSubst(a)  // existence is checked in MethodCall constructor
+      w.putType(tpe)
+    }
   }
 
   /** The SMethod instances in STypeCompanions may have type STypeIdent in methods types,
@@ -43,9 +49,36 @@ case class MethodCallSerializer(cons: (Value[SType], SMethod, IndexedSeq[Value[S
     val obj = r.getValue()
     val args = r.getValues()
     val method = SMethod.fromIds(typeId, methodId)
-    val nArgs = args.length
 
-    val types: Seq[SType] =
+    val explicitTypes = if (method.hasExplicitTypeArgs) {
+      val nTypes = method.explicitTypeArgs.length
+      val res = safeNewArray[SType](nTypes)
+      cfor(0)(_ < nTypes, _ + 1) { i =>
+        res(i) = r.getType()
+      }
+      ArraySeq.unsafeWrapArray(res)
+    } else SType.EmptySeq
+
+    val explicitTypeSubst = method.explicitTypeArgs.zip(explicitTypes).toMap
+    val specMethod = getSpecializedMethodFor(method, explicitTypeSubst, obj, args)
+
+    var isUsingBlockchainContext = specMethod.objType == SContextMethods &&
+      BlockchainContextMethodNames.contains(method.name)
+    r.wasUsingBlockchainContext ||= isUsingBlockchainContext
+
+    cons(obj, specMethod, args, explicitTypeSubst)
+  }
+
+  def getSpecializedMethodFor(
+    methodTemplate: SMethod,
+    explicitTypeSubst: STypeSubst,
+    obj: SValue,
+    args: Seq[SValue]
+  ): SMethod = {
+    // TODO optimize: avoid repeated transformation of method type
+    val method = methodTemplate.withConcreteTypes(explicitTypeSubst)
+    val nArgs = args.length
+    val argTypes: Seq[SType] =
       if (nArgs == 0) SType.EmptySeq
       else {
         val types = safeNewArray[SType](nArgs)
@@ -55,12 +88,6 @@ case class MethodCallSerializer(cons: (Value[SType], SMethod, IndexedSeq[Value[S
         types
       }
 
-    val specMethod = method.specializeFor(obj.tpe, types)
-
-    var isUsingBlockchainContext = specMethod.objType == SContextMethods &&
-      BlockchainContextMethodNames.contains(method.name)
-    r.wasUsingBlockchainContext ||= isUsingBlockchainContext
-
-    cons(obj, specMethod, args, Map.empty)
+    method.specializeFor(obj.tpe, argTypes)
   }
 }

sc/shared/src/main/scala/sigma/compiler/phases/SigmaTyper.scala

@@ -139,7 +139,8 @@ class SigmaTyper(val builder: SigmaBuilder,
       obj.tpe match {
         case p: SProduct =>
           MethodsContainer.getMethod(p, n) match {
-            case Some(method @ SMethod(_, _, genFunTpe @ SFunc(_, _, _), _, _, _, _, _)) =>
+            case Some(method: SMethod) =>
+              val genFunTpe = method.stype
               val subst = Map(genFunTpe.tpeParams.head.ident -> rangeTpe)
               val concrFunTpe = applySubst(genFunTpe, subst)
               val expectedArgs = concrFunTpe.asFunc.tDom.tail
@@ -511,6 +512,7 @@ class SigmaTyper(val builder: SigmaBuilder,
     case v: SigmaBoolean => v
     case v: Upcast[_, _] => v
     case v @ Select(_, _, Some(_)) => v
+    case v @ MethodCall(_, _, _, _) => v
     case v =>
       error(s"Don't know how to assignType($v)", v.sourceContext)
   }).ensuring(v => v.tpe != NoType,