move: advanced funcs to functional programming

27-functional-programming/log-parser-exp/textwriter.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"strings"
+)
+
+// TODO: sort by result key interfaces section
+
+func textWriter(w io.Writer, results []result) error {
+	fmt.Fprintf(w, "%-25s %-10s %10s %10s\n",
+		"DOMAINS", "PAGES", "VISITS", "UNIQUES")
+
+	fmt.Fprintln(w, strings.Repeat("-", 58))
+
+	var total result
+
+	for _, r := range results {
+		total = total.add(r)
+
+		fmt.Fprintf(w, "%-25s %-10s %10d %10d\n",
+			r.domain, r.page, r.visits, r.uniques)
+	}
+
+	fmt.Fprintf(w, "\n%-36s %10d %10d\n",
+		"", total.visits, total.uniques)
+
+	return nil
+}