impl all

ledger/delta.go

@@ -36,3 +36,12 @@ func newDelta(d time.Time, a ledger.Account) Delta {
 		Currency: USD, // TODO
 	}
 }
+
+func (delta Delta) Plus(other Delta) Delta {
+	return Delta{
+		Date:     other.Date,
+		Account:  delta.Account,
+		Value:    delta.Value + other.Value,
+		Currency: other.Currency,
+	}
+}

ledger/file.go

@@ -12,7 +12,7 @@ func NewFile(p string) (File, error) {
 	return f, err
 }
 
-func (file File) Deltas(likes ...Like) ([]Delta, error) {
+func (file File) Deltas(like ...Like) ([]Delta, error) {
 	transactions, err := file.transactions()
 	if err != nil {
 		return nil, err
@@ -20,14 +20,7 @@ func (file File) Deltas(likes ...Like) ([]Delta, error) {
 	result := make([]Delta, 0, len(transactions)*2)
 	for _, transaction := range transactions {
 		for _, delta := range newDeltas(transaction) {
-			if got := func() bool {
+			if !likes(like).all(delta) {
-				for _, like := range likes {
-					if !like(delta) {
-						return false
-					}
-				}
-				return true
-			}(); !got {
 				continue
 			}
 			result = append(result, delta)

ledger/like.go

@@ -4,6 +4,8 @@ import "regexp"
 
 type Like func(Delta) bool
 
+type likes []Like
+
 func LikeAcc(pattern string) Like {
 	return func(d Delta) bool {
 		return like(pattern, d.Account)
@@ -13,3 +15,12 @@ func LikeAcc(pattern string) Like {
 func like(pattern string, other string) bool {
 	return regexp.MustCompile(pattern).MatchString(other)
 }
+
+func (likes likes) all(delta Delta) bool {
+	for i := range likes {
+		if !likes[i](delta) {
+			return false
+		}
+	}
+	return true
+}