add: default from to log parser

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

@@ -9,15 +9,12 @@ package main
 
 import (
 	"fmt"
-	"os"
 )
 
 func main() {
 	defer recoverErr()
 
 	_, err := newReport().
-		from(textReader(os.Stdin)).
-		to(textWriter(os.Stdout)).
 		// filterBy(orgDomainsFilter).
 		filterBy(notUsing(domainExtFilter("com", "io"))).
 		groupBy(domainGrouper).

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

@@ -1,5 +1,7 @@
 package main
 
+import "os"
+
 type (
 	inputFunc  func() ([]result, error)
 	outputFunc func([]result) error
@@ -15,6 +17,8 @@ type report struct {
 func newReport() *report {
 	return &report{
 		filter: noopFilter,
+		input:  textReader(os.Stdin),
+		output: textWriter(os.Stdout),
 	}
 }
 

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

@@ -27,16 +27,18 @@ func parseText(in *bufio.Scanner) ([]result, error) {
 		lines   int
 	)
 
+	results = make([]result, 0, 5000000)
+
 	for in.Scan() {
 		lines++
 
-		result, err := parseFields(strings.Fields(in.Text()))
+		res, err := parseFields(strings.Fields(in.Text()))
 		if err != nil {
 			// TODO: custom error type for line information
 			return nil, fmt.Errorf("line %d: %v", lines, err)
 		}
 
-		results = append(results, result)
+		results = append(results, res)
 	}
 
 	if err := in.Err(); err != nil {