Add bytecode opcode for ValueFnRef

lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeCompiler.kt

@@ -175,7 +175,13 @@ class BytecodeCompiler(
                 CompiledValue(mapped, resolved)
             }
             is LocalVarRef -> compileNameLookup(ref.name)
-            is ValueFnRef -> compileEvalRef(ref)
+            is ValueFnRef -> {
+                val constId = builder.addConst(BytecodeConst.ValueFn(ref.valueFn()))
+                val slot = allocSlot()
+                builder.emit(Opcode.EVAL_VALUE_FN, constId, slot)
+                updateSlotType(slot, SlotType.OBJ)
+                CompiledValue(slot, SlotType.OBJ)
+            }
             is ListLiteralRef -> compileListLiteral(ref)
             is ThisMethodSlotCallRef -> compileThisMethodSlotCall(ref)
             is StatementRef -> {

lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/BytecodeConst.kt

@@ -32,6 +32,7 @@ sealed class BytecodeConst {
     data class Ref(val value: net.sergeych.lyng.obj.ObjRef) : BytecodeConst()
     data class StatementVal(val statement: net.sergeych.lyng.Statement) : BytecodeConst()
     data class ListLiteralPlan(val spreads: List<Boolean>) : BytecodeConst()
+    data class ValueFn(val fn: suspend (net.sergeych.lyng.Scope) -> net.sergeych.lyng.obj.ObjRecord) : BytecodeConst()
     data class SlotPlan(val plan: Map<String, Int>) : BytecodeConst()
     data class ExtensionPropertyDecl(
         val extTypeName: String,

lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/CmdBuilder.kt

@@ -184,7 +184,7 @@ class CmdBuilder {
                 listOf(OperandKind.SLOT, OperandKind.SLOT, OperandKind.SLOT)
             Opcode.LIST_LITERAL ->
                 listOf(OperandKind.CONST, OperandKind.SLOT, OperandKind.COUNT, OperandKind.SLOT)
-            Opcode.EVAL_FALLBACK, Opcode.EVAL_REF, Opcode.EVAL_STMT ->
+            Opcode.EVAL_FALLBACK, Opcode.EVAL_REF, Opcode.EVAL_STMT, Opcode.EVAL_VALUE_FN ->
                 listOf(OperandKind.ID, OperandKind.SLOT)
         }
     }
@@ -377,6 +377,7 @@ class CmdBuilder {
             Opcode.EVAL_FALLBACK -> CmdEvalFallback(operands[0], operands[1])
             Opcode.EVAL_REF -> CmdEvalRef(operands[0], operands[1])
             Opcode.EVAL_STMT -> CmdEvalStmt(operands[0], operands[1])
+            Opcode.EVAL_VALUE_FN -> CmdEvalValueFn(operands[0], operands[1])
         }
     }
 }

lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/CmdDisassembler.kt

@@ -187,6 +187,7 @@ object CmdDisassembler {
             is CmdEvalFallback -> Opcode.EVAL_FALLBACK to intArrayOf(cmd.id, cmd.dst)
             is CmdEvalRef -> Opcode.EVAL_REF to intArrayOf(cmd.id, cmd.dst)
             is CmdEvalStmt -> Opcode.EVAL_STMT to intArrayOf(cmd.id, cmd.dst)
+            is CmdEvalValueFn -> Opcode.EVAL_VALUE_FN to intArrayOf(cmd.id, cmd.dst)
         }
     }
 
@@ -268,7 +269,7 @@ object CmdDisassembler {
                 listOf(OperandKind.SLOT, OperandKind.SLOT, OperandKind.SLOT)
             Opcode.LIST_LITERAL ->
                 listOf(OperandKind.CONST, OperandKind.SLOT, OperandKind.COUNT, OperandKind.SLOT)
-            Opcode.EVAL_FALLBACK, Opcode.EVAL_REF, Opcode.EVAL_STMT ->
+            Opcode.EVAL_FALLBACK, Opcode.EVAL_REF, Opcode.EVAL_STMT, Opcode.EVAL_VALUE_FN ->
                 listOf(OperandKind.ID, OperandKind.SLOT)
         }
     }

lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/CmdRuntime.kt

@@ -1352,6 +1352,22 @@ class CmdEvalStmt(internal val id: Int, internal val dst: Int) : Cmd() {
     }
 }
 
+class CmdEvalValueFn(internal val id: Int, internal val dst: Int) : Cmd() {
+    override suspend fun perform(frame: CmdFrame) {
+        if (frame.fn.localSlotNames.isNotEmpty()) {
+            frame.syncFrameToScope()
+        }
+        val valueFn = frame.fn.constants.getOrNull(id) as? BytecodeConst.ValueFn
+            ?: error("EVAL_VALUE_FN expects ValueFn at $id")
+        val result = valueFn.fn(frame.scope).value
+        if (frame.fn.localSlotNames.isNotEmpty()) {
+            frame.syncScopeToFrame()
+        }
+        frame.storeObjResult(dst, result)
+        return
+    }
+}
+
 class CmdFrame(
     val vm: CmdVm,
     val fn: CmdFunction,

lynglib/src/commonMain/kotlin/net/sergeych/lyng/bytecode/Opcode.kt

@@ -145,6 +145,7 @@ enum class Opcode(val code: Int) {
     THROW(0xBB),
     EVAL_REF(0xBC),
     EVAL_STMT(0xBD),
+    EVAL_VALUE_FN(0xBE),
     ;
 
     companion object {

lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjRef.kt

@@ -66,6 +66,8 @@ sealed interface ObjRef {
 
 /** Runtime-computed read-only reference backed by a lambda. */
 class ValueFnRef(private val fn: suspend (Scope) -> ObjRecord) : ObjRef {
+    internal fun valueFn(): suspend (Scope) -> ObjRecord = fn
+
     override suspend fun get(scope: Scope): ObjRecord = fn(scope)
 }