initial commits

writerune.go

@@ -0,0 +1,26 @@
+package netln
+
+import (
+	"github.com/reiver/go-utf8"
+
+	"fmt"
+	"io"
+)
+
+// writeRune deals with writing a single rune.
+//
+// It also makes sure that any error condition is represented as a Go error.
+//
+// It also wraps any errors, and provides a more appropriate error message.
+func writeRune(writer io.Writer, r rune, expectedWritten int) error {
+
+	n, err := utf8.WriteRune(writer, r)
+	if nil != err {
+		return fmt.Errorf("problem writing UTF-8 character %U: %w", r, err)
+	}
+	if expectedWritten != n {
+		return fmt.Errorf("problem writing UTF-8 character %U — expected to write %d bytes, but actually wrote %b bytes", r, expectedWritten, n)
+	}
+
+	return nil
+}