examples: update examples

Closes #1234

examples/token/token.go

@@ -11,11 +11,16 @@ const (
 	multiplier = 100000000
 )
 
-var owner = util.FromAddress("NMipL5VsNoLUBUJKPKLhxaEbPQVCZnyJyB")
+var (
+	owner = util.FromAddress("NULwe3UAHckN2fzNdcVg31tDiaYtMDwANt")
+	token nep5.Token
+	ctx   storage.Context
+)
 
-// createToken initializes the Token Interface for the Smart Contract to operate with
-func createToken() nep5.Token {
-	return nep5.Token{
+// init initializes the Token Interface and storage context for the Smart
+// Contract to operate with
+func init() {
+	token = nep5.Token{
 		Name:           "Awesome NEO Token",
 		Symbol:         "ANT",
 		Decimals:       decimals,
@@ -23,95 +28,40 @@ func createToken() nep5.Token {
 		TotalSupply:    11000000 * multiplier,
 		CirculationKey: "TokenCirculation",
 	}
-}
-
-// Main function = contract entry
-func Main(operation string, args []interface{}) interface{} {
-	if operation == "name" {
-		return Name()
-	}
-	if operation == "symbol" {
-		return Symbol()
-	}
-	if operation == "decimals" {
-		return Decimals()
-	}
-
-	if operation == "totalSupply" {
-		return TotalSupply()
-	}
-
-	if operation == "balanceOf" {
-		hodler := args[0].([]byte)
-		return BalanceOf(hodler)
-	}
-
-	if operation == "transfer" && checkArgs(args, 3) {
-		from := args[0].([]byte)
-		to := args[1].([]byte)
-		amount := args[2].(int)
-		return Transfer(from, to, amount)
-	}
-
-	if operation == "mint" && checkArgs(args, 1) {
-		addr := args[0].([]byte)
-		return Mint(addr)
-	}
-
-	return true
-}
-
-// checkArgs checks args array against a length indicator
-func checkArgs(args []interface{}, length int) bool {
-	if len(args) == length {
-		return true
-	}
-
-	return false
+	ctx = storage.GetContext()
 }
 
 // Name returns the token name
 func Name() string {
-	t := createToken()
-	return t.Name
+	return token.Name
 }
 
 // Symbol returns the token symbol
 func Symbol() string {
-	t := createToken()
-	return t.Symbol
+	return token.Symbol
 }
 
 // Decimals returns the token decimals
 func Decimals() int {
-	t := createToken()
-	return t.Decimals
+	return token.Decimals
 }
 
 // TotalSupply returns the token total supply value
-func TotalSupply() interface{} {
-	t := createToken()
-	ctx := storage.GetContext()
-	return t.GetSupply(ctx)
+func TotalSupply() int {
+	return token.GetSupply(ctx)
 }
 
 // BalanceOf returns the amount of token on the specified address
 func BalanceOf(holder []byte) interface{} {
-	t := createToken()
-	ctx := storage.GetContext()
-	return t.BalanceOf(ctx, holder)
+	return token.BalanceOf(ctx, holder)
 }
 
 // Transfer token from one user to another
 func Transfer(from []byte, to []byte, amount int) bool {
-	t := createToken()
-	ctx := storage.GetContext()
-	return t.Transfer(ctx, from, to, amount)
+	return token.Transfer(ctx, from, to, amount)
 }
 
 // Mint initial supply of tokens
 func Mint(to []byte) bool {
-	t := createToken()
-	ctx := storage.GetContext()
-	return t.Mint(ctx, to)
+	return token.Mint(ctx, to)
 }