update input/outpu

output/writer.go

@@ -0,0 +1,45 @@
+package output
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"gitoa.ru/go-4devs/console/output/verbosity"
+)
+
+const newline = "\n"
+
+func Stderr() Output {
+	return New(os.Stderr, FormatString)
+}
+
+func Stdout() Output {
+	return New(os.Stdout, FormatString)
+}
+
+func Buffer(buf *bytes.Buffer) Output {
+	return New(buf, FormatString)
+}
+
+func FormatString(_ verbosity.Verbosity, msg string, kv ...KeyValue) string {
+	if len(kv) > 0 {
+		nline := ""
+		if msg[len(msg)-1:] == newline {
+			nline = newline
+		}
+
+		return "msg=\"" + strings.TrimSpace(msg) + "\", " + KeyValues(kv).String() + nline
+	}
+
+	return msg
+}
+
+func New(w io.Writer, format func(verb verbosity.Verbosity, msg string, kv ...KeyValue) string) Output {
+	return func(ctx context.Context, verb verbosity.Verbosity, msg string, kv ...KeyValue) (int, error) {
+		return fmt.Fprint(w, format(verb, msg, kv...))
+	}
+}