*: use slices.Index/slices.Contains where appropriate

This doesn't touch performance-sensitive parts, but simplifies a lot of code.

Signed-off-by: Roman Khimov <roman@nspcc.ru>

cli/wallet/wallet.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"math/big"
 	"os"
+	"slices"
 	"strings"
 
 	"github.com/nspcc-dev/neo-go/cli/cmdargs"
@@ -512,16 +513,13 @@ func exportKeys(ctx *cli.Context) error {
 
 	var wifs []string
 
-loop:
 	for _, a := range wall.Accounts {
 		if addr != "" && a.Address != addr {
 			continue
 		}
 
-		for i := range wifs {
-			if a.EncryptedWIF == wifs[i] {
-				continue loop
-			}
+		if slices.Contains(wifs, a.EncryptedWIF) {
+			continue
 		}
 
 		wifs = append(wifs, a.EncryptedWIF)

pkg/compiler/analysis.go

@@ -6,6 +6,7 @@ import (
 	"go/ast"
 	"go/token"
 	"go/types"
+	"slices"
 	"strings"
 
 	"github.com/nspcc-dev/neo-go/pkg/vm/emit"
@@ -697,12 +698,7 @@ func (c *codegen) pickVarsFromNodes(nodes []nodeContext, markAsUsed func(name st
 }
 
 func isGoBuiltin(name string) bool {
-	for i := range goBuiltins {
-		if name == goBuiltins[i] {
-			return true
-		}
-	}
-	return false
+	return slices.Contains(goBuiltins, name)
 }
 
 func isPotentialCustomBuiltin(f *funcScope, expr ast.Expr) bool {

pkg/compiler/types.go

@@ -3,6 +3,7 @@ package compiler
 import (
 	"go/ast"
 	"go/types"
+	"slices"
 
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 )
@@ -45,11 +46,7 @@ func (c *codegen) typeOf(e ast.Expr) types.Type {
 func isBasicTypeOfKind(typ types.Type, ks ...types.BasicKind) bool {
 	if t, ok := typ.Underlying().(*types.Basic); ok {
 		k := t.Kind()
-		for i := range ks {
-			if k == ks[i] {
-				return true
-			}
-		}
+		return slices.Contains(ks, k)
 	}
 	return false
 }

pkg/consensus/consensus.go

@@ -167,14 +167,9 @@ func NewService(cfg Config) (Service, error) {
 		}
 
 		// Check that the wallet password is correct for at least one account.
-		var ok bool
-		for _, acc := range srv.wallet.Accounts {
-			err := acc.Decrypt(srv.Config.Wallet.Password, srv.wallet.Scrypt)
-			if err == nil {
-				ok = true
-				break
-			}
-		}
+		var ok = slices.ContainsFunc(srv.wallet.Accounts, func(acc *wallet.Account) bool {
+			return acc.Decrypt(srv.Config.Wallet.Password, srv.wallet.Scrypt) == nil
+		})
 		if !ok {
 			return nil, errors.New("no account with provided password was found")
 		}

pkg/core/interop/runtime/witness.go

@@ -4,6 +4,7 @@ import (
 	"crypto/elliptic"
 	"errors"
 	"fmt"
+	"slices"
 
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
@@ -79,10 +80,8 @@ func checkScope(ic *interop.Context, hash util.Uint160) (bool, error) {
 			}
 			if c.Scopes&transaction.CustomContracts != 0 {
 				currentScriptHash := ic.VM.GetCurrentScriptHash()
-				for _, allowedContract := range c.AllowedContracts {
-					if allowedContract == currentScriptHash {
-						return true, nil
-					}
+				if slices.Contains(c.AllowedContracts, currentScriptHash) {
+					return true, nil
 				}
 			}
 			if c.Scopes&transaction.CustomGroups != 0 {
@@ -91,10 +90,8 @@ func checkScope(ic *interop.Context, hash util.Uint160) (bool, error) {
 					return false, err
 				}
 				// check if the current group is the required one
-				for _, allowedGroup := range c.AllowedGroups {
-					if groups.Contains(allowedGroup) {
-						return true, nil
-					}
+				if slices.ContainsFunc(c.AllowedGroups, groups.Contains) {
+					return true, nil
 				}
 			}
 			if c.Scopes&transaction.Rules != 0 {

pkg/crypto/keys/publickey.go

@@ -71,12 +71,7 @@ func (keys *PublicKeys) Bytes() []byte {
 
 // Contains checks whether the passed param is contained in PublicKeys.
 func (keys PublicKeys) Contains(pKey *PublicKey) bool {
-	for _, key := range keys {
-		if key.Equal(pKey) {
-			return true
-		}
-	}
-	return false
+	return slices.ContainsFunc(keys, pKey.Equal)
 }
 
 // Copy returns a shallow copy of the PublicKeys slice. It creates a new slice with the same elements,

pkg/services/notary/notary.go

@@ -6,6 +6,7 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
+	"slices"
 	"sync"
 	"sync/atomic"
 
@@ -131,18 +132,14 @@ func (r request) isMainCompleted() bool {
 // NewNotary returns a new Notary module.
 func NewNotary(cfg Config, net netmode.Magic, mp *mempool.Pool, onTransaction func(tx *transaction.Transaction) error) (*Notary, error) {
 	w := cfg.MainCfg.UnlockWallet
-	wallet, err := wallet.NewWalletFromFile(w.Path)
+	wall, err := wallet.NewWalletFromFile(w.Path)
 	if err != nil {
 		return nil, err
 	}
 
-	haveAccount := false
-	for _, acc := range wallet.Accounts {
-		if err := acc.Decrypt(w.Password, wallet.Scrypt); err == nil {
-			haveAccount = true
-			break
-		}
-	}
+	var haveAccount = slices.ContainsFunc(wall.Accounts, func(acc *wallet.Account) bool {
+		return acc.Decrypt(w.Password, wall.Scrypt) == nil
+	})
 	if !haveAccount {
 		return nil, errors.New("no wallet account could be unlocked")
 	}
@@ -151,7 +148,7 @@ func NewNotary(cfg Config, net netmode.Magic, mp *mempool.Pool, onTransaction fu
 		requests:      make(map[util.Uint256]*request),
 		Config:        cfg,
 		Network:       net,
-		wallet:        wallet,
+		wallet:        wall,
 		onTransaction: onTransaction,
 		newTxs:        make(chan txHashPair, defaultTxChannelCapacity),
 		mp:            mp,
@@ -260,10 +257,10 @@ func (n *Notary) OnNewRequest(payload *payload.P2PNotaryRequest) {
 	defer n.reqMtx.Unlock()
 	r, exists := n.requests[payload.MainTransaction.Hash()]
 	if exists {
-		for _, fb := range r.fallbacks {
-			if fb.Hash().Equals(payload.FallbackTransaction.Hash()) {
-				return // then we already have processed this request
-			}
+		if slices.ContainsFunc(r.fallbacks, func(fb *transaction.Transaction) bool {
+			return fb.Hash().Equals(payload.FallbackTransaction.Hash())
+		}) {
+			return // then we already have processed this request
 		}
 		r.minNotValidBefore = min(r.minNotValidBefore, nvbFallback)
 	} else {
@@ -447,13 +444,9 @@ func (n *Notary) newTxCallbackLoop() {
 			}
 			if !isMain {
 				// Ensure that fallback was not already completed.
-				var isPending bool
-				for _, fb := range r.fallbacks {
-					if fb.Hash() == tx.tx.Hash() {
-						isPending = true
-						break
-					}
-				}
+				var isPending = slices.ContainsFunc(r.fallbacks, func(fb *transaction.Transaction) bool {
+					return fb.Hash() == tx.tx.Hash()
+				})
 				if !isPending {
 					n.reqMtx.Unlock()
 					continue

pkg/services/oracle/network.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	"slices"
 	"syscall"
 
 	"github.com/nspcc-dev/neo-go/pkg/config"
@@ -39,12 +40,9 @@ func isReserved(ip net.IP) bool {
 	if !ip.IsGlobalUnicast() {
 		return true
 	}
-	for i := range privateNets {
-		if privateNets[i].Contains(ip) {
-			return true
-		}
-	}
-	return false
+	return slices.ContainsFunc(privateNets, func(pn net.IPNet) bool {
+		return pn.Contains(ip)
+	})
 }
 
 func getDefaultClient(cfg config.OracleConfiguration) *http.Client {

pkg/services/oracle/oracle.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"errors"
 	"net/http"
+	"slices"
 	"sync"
 	"time"
 
@@ -150,13 +151,9 @@ func NewOracle(cfg Config) (*Oracle, error) {
 		return nil, err
 	}
 
-	haveAccount := false
-	for _, acc := range o.wallet.Accounts {
-		if err := acc.Decrypt(w.Password, o.wallet.Scrypt); err == nil {
-			haveAccount = true
-			break
-		}
-	}
+	var haveAccount = slices.ContainsFunc(o.wallet.Accounts, func(acc *wallet.Account) bool {
+		return acc.Decrypt(w.Password, o.wallet.Scrypt) == nil
+	})
 	if !haveAccount {
 		return nil, errors.New("no wallet account could be unlocked")
 	}

pkg/services/oracle/request.go

@@ -6,6 +6,7 @@ import (
 	"mime"
 	"net/http"
 	"net/url"
+	"slices"
 	"time"
 
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
@@ -284,10 +285,5 @@ func checkMediaType(hdr string, allowed []string) bool {
 		return false
 	}
 
-	for _, ct := range allowed {
-		if ct == typ {
-			return true
-		}
-	}
-	return false
+	return slices.Contains(allowed, typ)
 }

pkg/services/stateroot/service.go

@@ -3,6 +3,7 @@ package stateroot
 import (
 	"errors"
 	"fmt"
+	"slices"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -112,13 +113,9 @@ func New(cfg config.StateRoot, sm *stateroot.Module, log *zap.Logger, bc Ledger,
 			return nil, err
 		}
 
-		haveAccount := false
-		for _, acc := range s.wallet.Accounts {
-			if err := acc.Decrypt(w.Password, s.wallet.Scrypt); err == nil {
-				haveAccount = true
-				break
-			}
-		}
+		var haveAccount = slices.ContainsFunc(s.wallet.Accounts, func(acc *wallet.Account) bool {
+			return acc.Decrypt(w.Password, s.wallet.Scrypt) == nil
+		})
 		if !haveAccount {
 			return nil, errors.New("no wallet account could be unlocked")
 		}

pkg/smartcontract/context/context.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"slices"
 	"sort"
 	"strings"
 
@@ -111,13 +112,9 @@ func (c *ParameterContext) AddSignature(h util.Uint160, ctr *wallet.Contract, pu
 			return errors.New("signature is already added")
 		}
 		pubBytes := pub.Bytes()
-		var contained bool
-		for i := range pubs {
-			if bytes.Equal(pubBytes, pubs[i]) {
-				contained = true
-				break
-			}
-		}
+		var contained = slices.ContainsFunc(pubs, func(p []byte) bool {
+			return bytes.Equal(pubBytes, p)
+		})
 		if !contained {
 			return errors.New("public key is not present in script")
 		}

pkg/smartcontract/manifest/container.go

@@ -7,6 +7,7 @@ package manifest
 import (
 	"bytes"
 	"encoding/json"
+	"slices"
 )
 
 // WildStrings represents a string set which can be a wildcard.
@@ -25,12 +26,7 @@ func (c *WildStrings) Contains(v string) bool {
 	if c.IsWildcard() {
 		return true
 	}
-	for _, s := range c.Value {
-		if v == s {
-			return true
-		}
-	}
-	return false
+	return slices.Contains(c.Value, v)
 }
 
 // Contains checks if v is in the container.
@@ -38,12 +34,7 @@ func (c *WildPermissionDescs) Contains(v PermissionDesc) bool {
 	if c.IsWildcard() {
 		return true
 	}
-	for _, u := range c.Value {
-		if u.Equals(v) {
-			return true
-		}
-	}
-	return false
+	return slices.ContainsFunc(c.Value, v.Equals)
 }
 
 // IsWildcard returns true iff the container is a wildcard.

pkg/smartcontract/manifest/group.go

@@ -5,6 +5,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"errors"
+	"slices"
 	"sort"
 
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
@@ -71,12 +72,9 @@ func (g Groups) AreValid(h util.Uint160) error {
 }
 
 func (g Groups) Contains(k *keys.PublicKey) bool {
-	for i := range g {
-		if k.Equal(g[i].PublicKey) {
-			return true
-		}
-	}
-	return false
+	return slices.ContainsFunc(g, func(gr Group) bool {
+		return k.Equal(gr.PublicKey)
+	})
 }
 
 // MarshalJSON implements the json.Marshaler interface.

pkg/smartcontract/manifest/manifest.go

@@ -77,12 +77,9 @@ func DefaultManifest(name string) *Manifest {
 // CanCall returns true if the current contract is allowed to call
 // the method of another contract with the specified hash.
 func (m *Manifest) CanCall(hash util.Uint160, toCall *Manifest, method string) bool {
-	for i := range m.Permissions {
-		if m.Permissions[i].IsAllowed(hash, toCall, method) {
-			return true
-		}
-	}
-	return false
+	return slices.ContainsFunc(m.Permissions, func(p Permission) bool {
+		return p.IsAllowed(hash, toCall, method)
+	})
 }
 
 // IsValid checks manifest internal consistency and correctness, one of the
@@ -95,10 +92,8 @@ func (m *Manifest) IsValid(hash util.Uint160, checkSize bool) error {
 		return errors.New("no name")
 	}
 
-	for i := range m.SupportedStandards {
-		if m.SupportedStandards[i] == "" {
-			return errors.New("invalid nameless supported standard")
-		}
+	if slices.Contains(m.SupportedStandards, "") {
+		return errors.New("invalid nameless supported standard")
 	}
 	if len(m.SupportedStandards) > 1 {
 		names := slices.Clone(m.SupportedStandards)
@@ -153,12 +148,7 @@ func (m *Manifest) IsValid(hash util.Uint160, checkSize bool) error {
 
 // IsStandardSupported denotes whether the specified standard is supported by the contract.
 func (m *Manifest) IsStandardSupported(standard string) bool {
-	for _, st := range m.SupportedStandards {
-		if st == standard {
-			return true
-		}
-	}
-	return false
+	return slices.Contains(m.SupportedStandards, standard)
 }
 
 // ToStackItem converts Manifest to stackitem.Item.

pkg/smartcontract/manifest/permission.go

@@ -121,10 +121,8 @@ func (d *PermissionDesc) Equals(v PermissionDesc) bool {
 
 // IsValid checks if Permission is correct.
 func (p *Permission) IsValid() error {
-	for i := range p.Methods.Value {
-		if p.Methods.Value[i] == "" {
-			return errors.New("empty method name")
-		}
+	if slices.Contains(p.Methods.Value, "") {
+		return errors.New("empty method name")
 	}
 	if len(p.Methods.Value) < 2 {
 		return nil
@@ -166,17 +164,10 @@ func (p *Permission) IsAllowed(hash util.Uint160, m *Manifest, method string) bo
 			return false
 		}
 	case PermissionGroup:
-		has := false
-		g := p.Contract.Group()
-		for i := range m.Groups {
-			if g.Equal(m.Groups[i].PublicKey) {
-				has = true
-				break
-			}
-		}
-		if !has {
-			return false
-		}
+		contractG := p.Contract.Group()
+		return slices.ContainsFunc(m.Groups, func(manifestG Group) bool {
+			return contractG.Equal(manifestG.PublicKey)
+		})
 	default:
 		panic(fmt.Sprintf("unexpected permission: %d", p.Contract.Type))
 	}

pkg/vm/stackitem/item.go

@@ -876,12 +876,9 @@ func (i *Map) String() string {
 
 // Index returns an index of the key in map.
 func (i *Map) Index(key Item) int {
-	for k := range i.value {
-		if i.value[k].Key.Equals(key) {
-			return k
-		}
-	}
-	return -1
+	return slices.IndexFunc(i.value, func(e MapElement) bool {
+		return e.Key.Equals(key)
+	})
 }
 
 // Has checks if the map has the specified key.

pkg/vm/vm.go

@@ -1873,7 +1873,10 @@ func (v *VM) ContractHasTryBlock() bool {
 // CheckMultisigPar checks if the sigs contains sufficient valid signatures.
 func CheckMultisigPar(v *VM, curve elliptic.Curve, h []byte, pkeys [][]byte, sigs [][]byte) bool {
 	if len(sigs) == 1 {
-		return checkMultisig1(v, curve, h, pkeys, sigs[0])
+		return slices.ContainsFunc(pkeys, func(keyb []byte) bool {
+			pkey := bytesToPublicKey(keyb, curve)
+			return pkey.Verify(sigs[0], h)
+		})
 	}
 
 	k1, k2 := 0, len(pkeys)-1
@@ -1963,17 +1966,6 @@ loop:
 	return sigok
 }
 
-func checkMultisig1(v *VM, curve elliptic.Curve, h []byte, pkeys [][]byte, sig []byte) bool {
-	for i := range pkeys {
-		pkey := bytesToPublicKey(pkeys[i], curve)
-		if pkey.Verify(sig, h) {
-			return true
-		}
-	}
-
-	return false
-}
-
 func cloneIfStruct(item stackitem.Item) stackitem.Item {
 	switch it := item.(type) {
 	case *stackitem.Struct:

pkg/wallet/account.go

@@ -3,6 +3,7 @@ package wallet
 import (
 	"errors"
 	"fmt"
+	"slices"
 
 	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
@@ -111,24 +112,16 @@ func NewContractAccount(hash util.Uint160, args ...any) *Account {
 
 // SignTx signs transaction t and updates it's Witnesses.
 func (a *Account) SignTx(net netmode.Magic, t *transaction.Transaction) error {
-	var (
-		haveAcc bool
-		pos     int
-	)
 	if a.Locked {
 		return errors.New("account is locked")
 	}
 	if a.Contract == nil {
 		return errors.New("account has no contract")
 	}
-	for i := range t.Signers {
-		if t.Signers[i].Account.Equals(a.ScriptHash()) {
-			haveAcc = true
-			pos = i
-			break
-		}
-	}
-	if !haveAcc {
+	var pos = slices.IndexFunc(t.Signers, func(s transaction.Signer) bool {
+		return s.Account.Equals(a.ScriptHash())
+	})
+	if pos == -1 {
 		return errors.New("transaction is not signed by this account")
 	}
 	if len(t.Scripts) < pos {
@@ -289,15 +282,7 @@ func (a *Account) ConvertMultisig(m int, pubs []*keys.PublicKey) error {
 // with m sufficient signatures. The encrypted private key is not modified and
 // remains the same.
 func (a *Account) ConvertMultisigEncrypted(accKey *keys.PublicKey, m int, pubs []*keys.PublicKey) error {
-	var found bool
-	for i := range pubs {
-		if accKey.Equal(pubs[i]) {
-			found = true
-			break
-		}
-	}
-
-	if !found {
+	if !slices.ContainsFunc(pubs, accKey.Equal) {
 		return errors.New("own public key was not found among multisig keys")
 	}