core,vm: remove System.Enumerator.* interops

Map iterator now returns key-value pair, while array/byte-array
iterators work like old enumerators.
Follow neo-project/neo#2190.

examples/iterator/iterator.go

@@ -9,13 +9,8 @@ import (
 // NotifyKeysAndValues sends notification with `foo` storage keys and values
 func NotifyKeysAndValues() bool {
 	iter := storage.Find(storage.GetContext(), []byte("foo"))
-	values := iterator.Values(iter)
-	keys := iterator.Keys(iter)
-
-	runtime.Notify("found storage values", values)
-	// For illustration purposes event is emitted with 'Any' type.
-	var typedKeys interface{} = keys
-	runtime.Notify("found storage keys", typedKeys)
-
+	for iterator.Next(iter) {
+		runtime.Notify("found storage key-value pair", iterator.Value(iter))
+	}
 	return true
 }

examples/iterator/iterator.yml

@@ -1,11 +1,7 @@
 name: "Iterator example"
 supportedstandards: []
 events:
-  - name: found storage values
+  - name: found storage key-value pair
     parameters:
-      - name: values
-        type: InteropInterface
-  - name: found storage keys
-    parameters:
-      - name: keys
+      - name: value
         type: Any

examples/storage/storage.go

@@ -35,9 +35,8 @@ func Find(value []byte) []string {
 	iter := storage.Find(ctx, value)
 	result := []string{}
 	for iterator.Next(iter) {
-		val := iterator.Value(iter)
-		key := iterator.Key(iter)
-		result = append(result, key.(string)+":"+val.(string))
+		val := iterator.Value(iter).([]string)
+		result = append(result, val[0]+":"+val[1])
 	}
 	return result
 }

pkg/compiler/syscall.go

@@ -35,18 +35,10 @@ var syscalls = map[string]map[string]string{
 		"RIPEMD160":                   interopnames.NeoCryptoRIPEMD160,
 		"SHA256":                      interopnames.NeoCryptoSHA256,
 	},
-	"enumerator": {
-		"Create": interopnames.SystemEnumeratorCreate,
-		"Next":   interopnames.SystemEnumeratorNext,
-		"Value":  interopnames.SystemEnumeratorValue,
-	},
 	"iterator": {
 		"Create": interopnames.SystemIteratorCreate,
-		"Key":    interopnames.SystemIteratorKey,
-		"Keys":   interopnames.SystemIteratorKeys,
-		"Next":   interopnames.SystemEnumeratorNext,
-		"Value":  interopnames.SystemEnumeratorValue,
-		"Values": interopnames.SystemIteratorValues,
+		"Next":   interopnames.SystemIteratorNext,
+		"Value":  interopnames.SystemIteratorValue,
 	},
 	"json": {
 		"Deserialize": interopnames.SystemJSONDeserialize,

pkg/core/interop/interopnames/names.go

@@ -26,13 +26,9 @@ const (
 	SystemContractGetCallFlags               = "System.Contract.GetCallFlags"
 	SystemContractNativeOnPersist            = "System.Contract.NativeOnPersist"
 	SystemContractNativePostPersist          = "System.Contract.NativePostPersist"
-	SystemEnumeratorCreate                   = "System.Enumerator.Create"
-	SystemEnumeratorNext                     = "System.Enumerator.Next"
-	SystemEnumeratorValue                    = "System.Enumerator.Value"
 	SystemIteratorCreate                     = "System.Iterator.Create"
-	SystemIteratorKey                        = "System.Iterator.Key"
-	SystemIteratorKeys                       = "System.Iterator.Keys"
-	SystemIteratorValues                     = "System.Iterator.Values"
+	SystemIteratorNext                       = "System.Iterator.Next"
+	SystemIteratorValue                      = "System.Iterator.Value"
 	SystemJSONDeserialize                    = "System.Json.Deserialize"
 	SystemJSONSerialize                      = "System.Json.Serialize"
 	SystemRuntimeCheckWitness                = "System.Runtime.CheckWitness"
@@ -89,13 +85,9 @@ var names = []string{
 	SystemContractGetCallFlags,
 	SystemContractNativeOnPersist,
 	SystemContractNativePostPersist,
-	SystemEnumeratorCreate,
-	SystemEnumeratorNext,
-	SystemEnumeratorValue,
 	SystemIteratorCreate,
-	SystemIteratorKey,
-	SystemIteratorKeys,
-	SystemIteratorValues,
+	SystemIteratorNext,
+	SystemIteratorValue,
 	SystemJSONDeserialize,
 	SystemJSONSerialize,
 	SystemRuntimeCheckWitness,

pkg/core/interop/iterator/interop.go

@@ -10,17 +10,14 @@ func Create(ic *interop.Context) error {
 	return vm.IteratorCreate(ic.VM)
 }
 
-// Key returns current iterator key.
-func Key(ic *interop.Context) error {
-	return vm.IteratorKey(ic.VM)
+// Next advances the iterator, pushes true on success and false otherwise.
+func Next(ic *interop.Context) error {
+	return vm.IteratorNext(ic.VM)
 }
 
-// Keys returns keys of the iterator.
-func Keys(ic *interop.Context) error {
-	return vm.IteratorKeys(ic.VM)
-}
-
-// Values returns values of the iterator.
-func Values(ic *interop.Context) error {
-	return vm.IteratorValues(ic.VM)
+// Value returns current iterator value and depends on iterator type:
+// For slices the result is just value.
+// For maps the result is key-value pair packed in a struct.
+func Value(ic *interop.Context) error {
+	return vm.IteratorValue(ic.VM)
 }

pkg/core/interop/iterator/interop_test.go

@@ -17,29 +17,19 @@ func TestIterator(t *testing.T) {
 	require.NoError(t, Create(ic))
 
 	res := ic.VM.Estack().Pop().Item()
-	ic.VM.Estack().PushVal(res)
-	require.NoError(t, vm.EnumeratorNext(ic.VM))
-	require.True(t, ic.VM.Estack().Pop().Bool())
-
-	ic.VM.Estack().PushVal(res)
-	require.NoError(t, Key(ic))
-	require.Equal(t, big.NewInt(0), ic.VM.Estack().Pop().BigInt())
+	for i := range full {
+		ic.VM.Estack().PushVal(res)
+		require.NoError(t, Next(ic))
+		require.True(t, ic.VM.Estack().Pop().Bool())
 
-	ic.VM.Estack().PushVal(res)
-	require.NoError(t, vm.EnumeratorValue(ic.VM))
-	require.Equal(t, big.NewInt(int64(full[0])), ic.VM.Estack().Pop().BigInt())
+		ic.VM.Estack().PushVal(res)
+		require.NoError(t, Value(ic))
 
-	ic.VM.Estack().PushVal(res)
-	require.NoError(t, vm.EnumeratorNext(ic.VM))
-	require.True(t, ic.VM.Estack().Pop().Bool())
-
-	ic.VM.Estack().PushVal(res)
-	require.NoError(t, Keys(ic))
-	require.NoError(t, vm.EnumeratorValue(ic.VM))
-	require.Equal(t, big.NewInt(1), ic.VM.Estack().Pop().BigInt())
+		value := ic.VM.Estack().Pop().Item().Value()
+		require.Equal(t, big.NewInt(int64(full[i])), value)
+	}
 
 	ic.VM.Estack().PushVal(res)
-	require.NoError(t, Values(ic))
-	require.NoError(t, vm.EnumeratorValue(ic.VM))
-	require.Equal(t, big.NewInt(int64(full[1])), ic.VM.Estack().Pop().BigInt())
+	require.NoError(t, Next(ic))
+	require.False(t, false, ic.VM.Estack().Pop().Bool())
 }

pkg/core/interop_neo_test.go

@@ -7,7 +7,6 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/block"
 	"github.com/nspcc-dev/neo-go/pkg/core/dao"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
-	"github.com/nspcc-dev/neo-go/pkg/core/interop/enumerator"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop/iterator"
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/storage"
@@ -67,33 +66,25 @@ func TestStorageFind(t *testing.T) {
 		require.NoError(t, err)
 
 		var iter *stackitem.Interop
-		require.NotPanics(t, func() { iter = v.Estack().Top().Interop() })
+		require.NotPanics(t, func() { iter = v.Estack().Pop().Interop() })
 
-		require.NoError(t, enumerator.Next(context))
-		require.True(t, v.Estack().Pop().Bool())
+		for _, id := range []int{2, 0} { // sorted indices with mathing prefix
+			v.Estack().PushVal(iter)
+			require.NoError(t, iterator.Next(context))
+			require.True(t, v.Estack().Pop().Bool())
 
-		v.Estack().PushVal(iter)
-		require.NoError(t, iterator.Key(context))
-		require.Equal(t, []byte{0x01, 0x01}, v.Estack().Pop().Bytes())
-
-		v.Estack().PushVal(iter)
-		require.NoError(t, enumerator.Value(context))
-		require.Equal(t, []byte{0x03, 0x04, 0x05, 0x06}, v.Estack().Pop().Bytes())
-
-		v.Estack().PushVal(iter)
-		require.NoError(t, enumerator.Next(context))
-		require.True(t, v.Estack().Pop().Bool())
-
-		v.Estack().PushVal(iter)
-		require.NoError(t, iterator.Key(context))
-		require.Equal(t, []byte{0x01, 0x02}, v.Estack().Pop().Bytes())
+			v.Estack().PushVal(iter)
+			require.NoError(t, iterator.Value(context))
 
-		v.Estack().PushVal(iter)
-		require.NoError(t, enumerator.Value(context))
-		require.Equal(t, []byte{0x01, 0x02, 0x03, 0x04}, v.Estack().Pop().Bytes())
+			kv, ok := v.Estack().Pop().Value().([]stackitem.Item)
+			require.True(t, ok)
+			require.Len(t, kv, 2)
+			require.Equal(t, skeys[id], kv[0].Value())
+			require.Equal(t, items[id].Value, kv[1].Value())
+		}
 
 		v.Estack().PushVal(iter)
-		require.NoError(t, enumerator.Next(context))
+		require.NoError(t, iterator.Next(context))
 		require.False(t, v.Estack().Pop().Bool())
 	})
 
@@ -104,7 +95,7 @@ func TestStorageFind(t *testing.T) {
 		err := storageFind(context)
 		require.NoError(t, err)
 
-		require.NoError(t, enumerator.Next(context))
+		require.NoError(t, iterator.Next(context))
 		require.False(t, v.Estack().Pop().Bool())
 	})
 
@@ -122,7 +113,7 @@ func TestStorageFind(t *testing.T) {
 		v.Estack().PushVal(stackitem.NewInterop(&StorageContext{ID: invalidID}))
 
 		require.NoError(t, storageFind(context))
-		require.NoError(t, enumerator.Next(context))
+		require.NoError(t, iterator.Next(context))
 		require.False(t, v.Estack().Pop().Bool())
 	})
 }

pkg/core/interops.go

@@ -12,7 +12,6 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/interop/binary"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop/contract"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop/crypto"
-	"github.com/nspcc-dev/neo-go/pkg/core/interop/enumerator"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop/interopnames"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop/iterator"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop/json"
@@ -58,13 +57,9 @@ var systemInterops = []interop.Function{
 	{Name: interopnames.SystemContractGetCallFlags, Func: contractGetCallFlags, Price: 1 << 10},
 	{Name: interopnames.SystemContractNativeOnPersist, Func: native.OnPersist, Price: 0, RequiredFlags: callflag.WriteStates},
 	{Name: interopnames.SystemContractNativePostPersist, Func: native.PostPersist, Price: 0, RequiredFlags: callflag.WriteStates},
-	{Name: interopnames.SystemEnumeratorCreate, Func: enumerator.Create, Price: 1 << 4, ParamCount: 1},
-	{Name: interopnames.SystemEnumeratorNext, Func: enumerator.Next, Price: 1 << 15, ParamCount: 1},
-	{Name: interopnames.SystemEnumeratorValue, Func: enumerator.Value, Price: 1 << 4, ParamCount: 1},
 	{Name: interopnames.SystemIteratorCreate, Func: iterator.Create, Price: 1 << 4, ParamCount: 1},
-	{Name: interopnames.SystemIteratorKey, Func: iterator.Key, Price: 1 << 4, ParamCount: 1},
-	{Name: interopnames.SystemIteratorKeys, Func: iterator.Keys, Price: 1 << 4, ParamCount: 1},
-	{Name: interopnames.SystemIteratorValues, Func: iterator.Values, Price: 1 << 4, ParamCount: 1},
+	{Name: interopnames.SystemIteratorNext, Func: iterator.Next, Price: 1 << 15, ParamCount: 1},
+	{Name: interopnames.SystemIteratorValue, Func: iterator.Value, Price: 1 << 4, ParamCount: 1},
 	{Name: interopnames.SystemJSONDeserialize, Func: json.Deserialize, Price: 1 << 14, ParamCount: 1},
 	{Name: interopnames.SystemJSONSerialize, Func: json.Serialize, Price: 1 << 12, ParamCount: 1},
 	{Name: interopnames.SystemRuntimeCheckWitness, Func: runtime.CheckWitness, Price: 1 << 10,