a reg

cmd/cli/main.go

@@ -3,6 +3,8 @@ package cli
 import (
 	"flag"
 	"fmt"
+	"io"
+	"maps"
 	"os"
 	"slices"
 
@@ -85,6 +87,40 @@ func Main() {
 			balances = balances.NotLike(notLikePattern)
 		}
 
+		FPrintBalances(os.Stdout, balances)
+	case "reg":
+		register := deltas.Register()
+		if likePattern != "" {
+			register = register.Like(likePattern)
+		}
+		if notLikePattern != "" {
+			register = register.NotLike(notLikePattern)
+		}
+
+		var prev ledger.Balances
+		for _, date := range register.Dates() {
+			balances := register[date]
+
+			newBalances := make(ledger.Balances)
+			for k, v := range balances {
+				if got := prev[k]; !maps.Equal(v, got) {
+					newBalances[k] = v
+				}
+			}
+
+			if len(newBalances) > 0 {
+				fmt.Println(date)
+				FPrintBalances(os.Stdout, newBalances)
+			}
+
+			prev = balances
+		}
+	default:
+		panic("unknown command " + positional[0])
+	}
+}
+
+func FPrintBalances(w io.Writer, balances ledger.Balances) {
 	keys := []string{}
 	for k := range balances {
 		keys = append(keys, k)
@@ -100,17 +136,18 @@ func Main() {
 
 	format := fmt.Sprintf("%%-%ds\t%%s%%.2f\n", max)
 	for _, key := range keys {
-			for currency, v := range balances[key] {
-				if currency != "$" {
-					currency += " "
+		currencies := []ledger.Currency{}
+		for currency := range balances[key] {
+			currencies = append(currencies, currency)
 		}
-				fmt.Printf(format, key, currency, v)
+		slices.Sort(currencies)
+
+		for _, currency := range currencies {
+			printableCurrency := currency
+			if printableCurrency != "$" {
+				printableCurrency += " "
+			}
+			fmt.Fprintf(w, format, key, printableCurrency, balances[key][currency])
 		}
 	}
-	case "reg":
-		// register := deltas.Register()
-		panic(cmd)
-	default:
-		panic("unknown command " + positional[0])
-	}
 }

src/ledger/register.go

@@ -51,6 +51,26 @@ func (register Register) Names() []string {
 	return result
 }
 
+func (register Register) Like(pattern string) Register {
+	result := make(Register)
+	for k, v := range register {
+		if got := v.Like(pattern); len(got) > 0 {
+			result[k] = got
+		}
+	}
+	return result
+}
+
+func (register Register) NotLike(pattern string) Register {
+	result := make(Register)
+	for k, v := range register {
+		if got := v.NotLike(pattern); len(got) > 0 {
+			result[k] = got
+		}
+	}
+	return result
+}
+
 func (register Register) Dates() []string {
 	result := make([]string, 0, len(register))
 	for k := range register {