move: advanced funcs to functional programming

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

@@ -0,0 +1,49 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func main() {
+	defer recoverErr()
+
+	_, err := newReport().
+		from(os.Stdin).
+		to(os.Stdout).
+		retrieveFrom(textReader).
+		filterBy(orgDomainsFilter).
+		// filterBy(not(domainExtFilter("org", "io"))).
+		// groupBy(pageGrouper).
+		groupBy(domainGrouper).
+		writeTo(textWriter).
+		run()
+
+	if err != nil {
+		fmt.Println("> Err:", err)
+	}
+}
+
+func recoverErr() {
+	val := recover()
+
+	if val == nil {
+		return
+	}
+
+	if err, ok := val.(string); ok {
+		fmt.Println("> Error occurred:", err)
+	}
+}
+
+/*
+newReport -> stats.NewReport().
+Result    -> stats.Record
+*/