refactor: log parser names (again :))

27-functional-programming/log-parser-exp/log.txt

@@ -1,4 +1,4 @@
-learngoprogramming.com.tr / 10 5
+learngoprogramming.com / 10 5
 learngoprogramming.com /courses 15 10
 learngoprogramming.com /courses 10 5
 learngoprogramming.com /articles 20 15

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

@@ -16,15 +16,12 @@ func main() {
 	defer recoverErr()
 
 	_, err := newReport().
-		from(os.Stdin).
+		from(textReader(os.Stdin)).
-		to(os.Stdout).
+		to(textWriter(os.Stdout)).
-		retrieveFrom(textReader).
+		// filterBy(orgDomainsFilter).
-		filterBy(orgDomainsFilter).
+		filterBy(notUsing(domainExtFilter("com", "io"))).
-		// filterBy(notUsing(domainExtFilter("org", "io"))).
-		// groupBy(pageGrouper).
 		groupBy(domainGrouper).
-		writeTo(textWriter).
+		start()
-		run()
 
 	if err != nil {
 		fmt.Println("> Err:", err)
@@ -49,12 +46,11 @@ Result    -> report.Line
 
 notUsing = report.Not
 
-_, err := stats.Parse().
+_, err := report.New().
-	From(os.Stdin).
+	From(report.TextReader(os.Stdin)).
-	To(os.Stdout).
+	To(report.TextWriter(os.Stdout)).
-	RetrieveFrom(stats.TextReader).
+	// FilterBy(report.OrgDomainsFilter).
-	FilterBy(notUsing(stats.DomainExtFilter("org", "io"))).
+	FilterBy(notUsing(report.DomainExtFilter("com", "io"))).
-	GroupBy(stats.DomainGrouper).
+	GroupBy(report.DomainGrouper).
-	WriteTo(stats.TextWriter).
+	Start()
-	Run()
 */

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

@@ -1,19 +1,15 @@
 package main
 
-import "io"
-
 type (
-	retrieveFunc func(io.Reader) ([]result, error)
+	inputFunc  func() ([]result, error)
-	writeFunc    func(io.Writer, []result) error
+	outputFunc func([]result) error
 )
 
 type report struct {
-	input    io.Reader
+	input  inputFunc
-	output   io.Writer
+	filter filterFunc
-	retrieve retrieveFunc
+	group  groupFunc
-	filter   filterFunc
+	output outputFunc
-	group    groupFunc
-	write    writeFunc
 }
 
 func newReport() *report {
@@ -22,18 +18,13 @@ func newReport() *report {
 	}
 }
 
-func (r *report) from(reader io.Reader) *report {
+func (r *report) from(fn inputFunc) *report {
-	r.input = reader
+	r.input = fn
 	return r
 }
 
-func (r *report) to(writer io.Writer) *report {
+func (r *report) to(fn outputFunc) *report {
-	r.output = writer
+	r.output = fn
-	return r
-}
-
-func (r *report) retrieveFrom(fn retrieveFunc) *report {
-	r.retrieve = fn
 	return r
 }
 
@@ -47,17 +38,12 @@ func (r *report) groupBy(fn groupFunc) *report {
 	return r
 }
 
-func (r *report) writeTo(fn writeFunc) *report {
+func (r *report) start() ([]result, error) {
-	r.write = fn
+	if r.input == nil {
-	return r
+		panic("report input cannot be nil")
-}
-
-func (r *report) run() ([]result, error) {
-	if r.retrieve == nil {
-		panic("report retrieve cannot be nil")
 	}
 
-	results, err := r.retrieve(r.input)
+	results, err := r.input()
 	if err != nil {
 		return nil, err
 	}
@@ -72,8 +58,8 @@ func (r *report) run() ([]result, error) {
 	}
 
 	// TODO: prefer: noop writer
-	if r.write != nil {
+	if r.output != nil {
-		if err := r.write(r.output, results); err != nil {
+		if err := r.output(results); err != nil {
 			return nil, err
 		}
 	}

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

@@ -14,9 +14,11 @@ import (
 	"strings"
 )
 
-func textReader(r io.Reader) ([]result, error) {
+func textReader(r io.Reader) inputFunc {
-	in := bufio.NewScanner(r)
+	return func() ([]result, error) {
-	return parseText(in)
+		in := bufio.NewScanner(r)
+		return parseText(in)
+	}
 }
 
 func parseText(in *bufio.Scanner) ([]result, error) {

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

@@ -19,17 +19,19 @@ const (
 	dashLength = 58
 )
 
-func textWriter(w io.Writer, results []result) error {
+func textWriter(w io.Writer) outputFunc {
-	fmt.Fprintf(w, header, "DOMAINS", "PAGES", "VISITS", "UNIQUES")
+	return func(results []result) error {
-	fmt.Fprintln(w, strings.Repeat("-", dashLength))
+		fmt.Fprintf(w, header, "DOMAINS", "PAGES", "VISITS", "UNIQUES")
+		fmt.Fprintln(w, strings.Repeat("-", dashLength))
 
-	var total result
+		var total result
-	for _, r := range results {
+		for _, r := range results {
-		total = total.add(r)
+			total = total.add(r)
-		fmt.Fprintf(w, line, r.domain, r.page, r.visits, r.uniques)
+			fmt.Fprintf(w, line, r.domain, r.page, r.visits, r.uniques)
+		}
+
+		fmt.Fprintf(w, footer, "", total.visits, total.uniques)
+
+		return nil
 	}
-
-	fmt.Fprintf(w, footer, "", total.visits, total.uniques)
-
-	return nil
 }