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coin.go
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coin.go
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package types
import (
"fmt"
"regexp"
"sort"
"strconv"
"strings"
)
// Coin hold some amount of one currency
type Coin struct {
Denom string `json:"denom"`
Amount Int `json:"amount"`
}
func NewCoin(denom string, amount Int) Coin {
return Coin{
Denom: denom,
Amount: amount,
}
}
func NewInt64Coin(denom string, amount int64) Coin {
return NewCoin(denom, NewInt(amount))
}
// String provides a human-readable representation of a coin
func (coin Coin) String() string {
return fmt.Sprintf("%v%v", coin.Amount, coin.Denom)
}
// SameDenomAs returns true if the two coins are the same denom
func (coin Coin) SameDenomAs(other Coin) bool {
return (coin.Denom == other.Denom)
}
// IsZero returns if this represents no money
func (coin Coin) IsZero() bool {
return coin.Amount.IsZero()
}
// IsGTE returns true if they are the same type and the receiver is
// an equal or greater value
func (coin Coin) IsGTE(other Coin) bool {
return coin.SameDenomAs(other) && (!coin.Amount.LT(other.Amount))
}
// IsLT returns true if they are the same type and the receiver is
// a smaller value
func (coin Coin) IsLT(other Coin) bool {
return !coin.IsGTE(other)
}
// IsEqual returns true if the two sets of Coins have the same value
func (coin Coin) IsEqual(other Coin) bool {
return coin.SameDenomAs(other) && (coin.Amount.Equal(other.Amount))
}
// IsPositive returns true if coin amount is positive
func (coin Coin) IsPositive() bool {
return (coin.Amount.Sign() == 1)
}
// IsNotNegative returns true if coin amount is not negative
func (coin Coin) IsNotNegative() bool {
return (coin.Amount.Sign() != -1)
}
// Adds amounts of two coins with same denom
func (coin Coin) Plus(coinB Coin) Coin {
if !coin.SameDenomAs(coinB) {
return coin
}
return Coin{coin.Denom, coin.Amount.Add(coinB.Amount)}
}
// Subtracts amounts of two coins with same denom
func (coin Coin) Minus(coinB Coin) Coin {
if !coin.SameDenomAs(coinB) {
return coin
}
return Coin{coin.Denom, coin.Amount.Sub(coinB.Amount)}
}
//----------------------------------------
// Coins
// Coins is a set of Coin, one per currency
type Coins []Coin
func (coins Coins) String() string {
if len(coins) == 0 {
return ""
}
out := ""
for _, coin := range coins {
out += fmt.Sprintf("%v,", coin.String())
}
return out[:len(out)-1]
}
// IsValid asserts the Coins are sorted, and don't have 0 amounts
func (coins Coins) IsValid() bool {
switch len(coins) {
case 0:
return true
case 1:
return !coins[0].IsZero()
default:
lowDenom := coins[0].Denom
for _, coin := range coins[1:] {
if coin.Denom <= lowDenom {
return false
}
if coin.IsZero() {
return false
}
// we compare each coin against the last denom
lowDenom = coin.Denom
}
return true
}
}
// Plus combines two sets of coins
// CONTRACT: Plus will never return Coins where one Coin has a 0 amount.
func (coins Coins) Plus(coinsB Coins) Coins {
sum := ([]Coin)(nil)
indexA, indexB := 0, 0
lenA, lenB := len(coins), len(coinsB)
for {
if indexA == lenA {
if indexB == lenB {
return sum
}
return append(sum, coinsB[indexB:]...)
} else if indexB == lenB {
return append(sum, coins[indexA:]...)
}
coinA, coinB := coins[indexA], coinsB[indexB]
switch strings.Compare(coinA.Denom, coinB.Denom) {
case -1:
sum = append(sum, coinA)
indexA++
case 0:
if coinA.Amount.Add(coinB.Amount).IsZero() {
// ignore 0 sum coin type
} else {
sum = append(sum, coinA.Plus(coinB))
}
indexA++
indexB++
case 1:
sum = append(sum, coinB)
indexB++
}
}
}
// Negative returns a set of coins with all amount negative
func (coins Coins) Negative() Coins {
res := make([]Coin, 0, len(coins))
for _, coin := range coins {
res = append(res, Coin{
Denom: coin.Denom,
Amount: coin.Amount.Neg(),
})
}
return res
}
// Minus subtracts a set of coins from another (adds the inverse)
func (coins Coins) Minus(coinsB Coins) Coins {
return coins.Plus(coinsB.Negative())
}
// IsGTE returns True iff coins is NonNegative(), and for every
// currency in coinsB, the currency is present at an equal or greater
// amount in coinsB
func (coins Coins) IsGTE(coinsB Coins) bool {
diff := coins.Minus(coinsB)
if len(diff) == 0 {
return true
}
return diff.IsNotNegative()
}
// IsLT returns True iff every currency in coins, the currency is
// present at a smaller amount in coins
func (coins Coins) IsLT(coinsB Coins) bool {
return !coins.IsGTE(coinsB)
}
// IsZero returns true if there are no coins
// or all coins are zero.
func (coins Coins) IsZero() bool {
for _, coin := range coins {
if !coin.IsZero() {
return false
}
}
return true
}
// IsEqual returns true if the two sets of Coins have the same value
func (coins Coins) IsEqual(coinsB Coins) bool {
if len(coins) != len(coinsB) {
return false
}
for i := 0; i < len(coins); i++ {
if coins[i].Denom != coinsB[i].Denom || !coins[i].Amount.Equal(coinsB[i].Amount) {
return false
}
}
return true
}
// IsPositive returns true if there is at least one coin, and all
// currencies have a positive value
func (coins Coins) IsPositive() bool {
if len(coins) == 0 {
return false
}
for _, coin := range coins {
if !coin.IsPositive() {
return false
}
}
return true
}
// IsNotNegative returns true if there is no currency with a negative value
// (even no coins is true here)
func (coins Coins) IsNotNegative() bool {
if len(coins) == 0 {
return true
}
for _, coin := range coins {
if !coin.IsNotNegative() {
return false
}
}
return true
}
// Returns the amount of a denom from coins
func (coins Coins) AmountOf(denom string) Int {
switch len(coins) {
case 0:
return ZeroInt()
case 1:
coin := coins[0]
if coin.Denom == denom {
return coin.Amount
}
return ZeroInt()
default:
midIdx := len(coins) / 2 // 2:1, 3:1, 4:2
coin := coins[midIdx]
if denom < coin.Denom {
return coins[:midIdx].AmountOf(denom)
} else if denom == coin.Denom {
return coin.Amount
} else {
return coins[midIdx+1:].AmountOf(denom)
}
}
}
//----------------------------------------
// Sort interface
//nolint
func (coins Coins) Len() int { return len(coins) }
func (coins Coins) Less(i, j int) bool { return coins[i].Denom < coins[j].Denom }
func (coins Coins) Swap(i, j int) { coins[i], coins[j] = coins[j], coins[i] }
var _ sort.Interface = Coins{}
// Sort is a helper function to sort the set of coins inplace
func (coins Coins) Sort() Coins {
sort.Sort(coins)
return coins
}
//----------------------------------------
// Parsing
var (
// Denominations can be 3 ~ 16 characters long.
reDnm = `[[:alpha:]][[:alnum:]]{2,15}`
reAmt = `[[:digit:]]+`
reSpc = `[[:space:]]*`
reCoin = regexp.MustCompile(fmt.Sprintf(`^(%s)%s(%s)$`, reAmt, reSpc, reDnm))
)
// ParseCoin parses a cli input for one coin type, returning errors if invalid.
// This returns an error on an empty string as well.
func ParseCoin(coinStr string) (coin Coin, err error) {
coinStr = strings.TrimSpace(coinStr)
matches := reCoin.FindStringSubmatch(coinStr)
if matches == nil {
err = fmt.Errorf("invalid coin expression: %s", coinStr)
return
}
denomStr, amountStr := matches[2], matches[1]
amount, err := strconv.Atoi(amountStr)
if err != nil {
return
}
return Coin{denomStr, NewInt(int64(amount))}, nil
}
// ParseCoins will parse out a list of coins separated by commas.
// If nothing is provided, it returns nil Coins.
// Returned coins are sorted.
func ParseCoins(coinsStr string) (coins Coins, err error) {
coinsStr = strings.TrimSpace(coinsStr)
if len(coinsStr) == 0 {
return nil, nil
}
coinStrs := strings.Split(coinsStr, ",")
for _, coinStr := range coinStrs {
coin, err := ParseCoin(coinStr)
if err != nil {
return nil, err
}
coins = append(coins, coin)
}
// Sort coins for determinism.
coins.Sort()
// Validate coins before returning.
if !coins.IsValid() {
return nil, fmt.Errorf("parseCoins invalid: %#v", coins)
}
return coins, nil
}