remove: log parser from interfaces

interfaces/log-parser/01-methods/changes.md

@@ -1,36 +0,0 @@
-# Problem
-
-## All these functions operate on a *parser value:
-+ `main.go`:
-  + `summarize(*p parser)`
-+ `parser.go`:
-  + `func parse(p *parser, line string) (r result)`
-  + `func update(p *parser, r result)`
-  + `func err(p *parser) error`
-
-## What is an object in Go?
-+ Object = A value of a type : `&parser{}` is an object.
-  + `type parser struct` is the definition (class/blueprint) of the object.
-
-### Methods are behaviors of objects:
-+ Parser needs to parse, update (analyse) the parsings, and report an error if any.
-+ Parser also needs to summarize the results.
-+ So, all these functions belong to a parser object.
-
-# Solution
-
-+ Attach the functions to the parser using methods.
-+ Methods are the behavior of the parser.
-+ Keep the methods that belong to a single type in the same file.
-
-1. Move the `summarize` into `parser.go`.
-2. `parser.go`: Use methods.
-3. `main()`   : Use methods of the `parser`.
-
-# Convince
-
-+ `p.` shows the fields and methods belong to the `parser`.
-+ `p.` selects a method from the method set of the `parser`.
-+ `p.method` sends the `p` as the first parameter to the method.
-+ `p` is the receiver: `*pointer`. It's a pointer receiver.
-+ Receiver is copied to the method.

interfaces/log-parser/01-methods/log.txt

@@ -1,16 +0,0 @@
-learngoprogramming.com 10
-learngoprogramming.com 15
-learngoprogramming.com 10
-learngoprogramming.com 20
-learngoprogramming.com 5
-golang.org 40
-golang.org 20
-golang.org 45
-golang.org 15
-blog.golang.org 60
-blog.golang.org 30
-blog.golang.org 20
-blog.golang.org 65
-blog.golang.org 15
-inanc.io 30
-inanc.io 70

interfaces/log-parser/01-methods/log_err_missing.txt

@@ -1,16 +0,0 @@
-learngoprogramming.com 10
-learngoprogramming.com 15
-learngoprogramming.com 10
-learngoprogramming.com 20
-learngoprogramming.com
-golang.org 40
-golang.org 20
-golang.org 45
-golang.org 15
-blog.golang.org 60
-blog.golang.org 30
-blog.golang.org 20
-blog.golang.org 65
-blog.golang.org 15
-inanc.io 30
-inanc.io 70

interfaces/log-parser/01-methods/log_err_negative.txt

@@ -1,16 +0,0 @@
-learngoprogramming.com 10
-learngoprogramming.com 15
-learngoprogramming.com 10
-learngoprogramming.com 20
-learngoprogramming.com 5
-golang.org 40
-golang.org 20
-golang.org -50
-golang.org 15
-blog.golang.org 60
-blog.golang.org 30
-blog.golang.org 20
-blog.golang.org 65
-blog.golang.org 15
-inanc.io 30
-inanc.io 70

interfaces/log-parser/01-methods/log_err_str.txt

@@ -1,16 +0,0 @@
-learngoprogramming.com 10
-learngoprogramming.com 15
-learngoprogramming.com 10
-learngoprogramming.com 20
-learngoprogramming.com 5
-golang.org FORTY
-golang.org 20
-golang.org 45
-golang.org 15
-blog.golang.org 60
-blog.golang.org 30
-blog.golang.org 20
-blog.golang.org 65
-blog.golang.org 15
-inanc.io 30
-inanc.io 70

interfaces/log-parser/01-methods/main.go

@@ -1,39 +0,0 @@
-// 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 (
-	"bufio"
-	"fmt"
-	"os"
-)
-
-func main() {
-	p := newParser()
-
-	fmt.Printf("%T\n", (*parser).parse)
-	return
-
-	in := bufio.NewScanner(os.Stdin)
-	for in.Scan() {
-		parsed := p.parse(in.Text())
-		p.update(parsed)
-	}
-
-	p.summarize()
-	dumpErrs([]error{in.Err(), p.err()})
-}
-
-// dumpErrs together to simplify multiple error handling
-func dumpErrs(errs []error) {
-	for _, err := range errs {
-		if err != nil {
-			fmt.Println("> Err:", err)
-		}
-	}
-}

interfaces/log-parser/01-methods/parser.go

@@ -1,100 +0,0 @@
-// 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"
-	"sort"
-	"strconv"
-	"strings"
-)
-
-// result stores details about a log line
-type result struct {
-	domain string
-	visits int
-	// add more metrics when needed
-}
-
-// parser keep tracks of the parsing
-type parser struct {
-	sum     map[string]result // metrics per domain
-	domains []string          // unique domain names
-	total   int               // total visits for all domains
-	lines   int               // number of parsed lines (for the error messages)
-	lerr    error             // the last error occurred
-}
-
-// newParser creates and returns a new parser
-func newParser() *parser {
-	return &parser{sum: make(map[string]result)}
-}
-
-// parse result from a log line
-func (p *parser) parse(line string) (r result) {
-	if p.lerr != nil {
-		return
-	}
-
-	p.lines++
-
-	fields := strings.Fields(line)
-	if len(fields) != 2 {
-		p.lerr = fmt.Errorf("wrong input: %v (line #%d)", fields, p.lines)
-		return
-	}
-
-	var err error
-
-	r.domain = fields[0]
-	r.visits, err = strconv.Atoi(fields[1])
-
-	if r.visits < 0 || err != nil {
-		p.lerr = fmt.Errorf("wrong input: %q (line #%d)", fields[1], p.lines)
-	}
-	return
-}
-
-// update the parsing results
-func (p *parser) update(r result) {
-	if p.lerr != nil {
-		return
-	}
-
-	// collect unique domains for easy access to sum map
-	if _, ok := p.sum[r.domain]; !ok {
-		p.domains = append(p.domains, r.domain)
-	}
-
-	// keep track of total visits
-	p.total += r.visits
-
-	// group the log lines by domain
-	p.sum[r.domain] = result{
-		domain: r.domain,
-		visits: r.visits + p.sum[r.domain].visits,
-	}
-}
-
-// summarize the parsing results
-func (p *parser) summarize() {
-	sort.Strings(p.domains)
-
-	fmt.Printf("%-30s %10s\n", "DOMAIN", "VISITS")
-	fmt.Println(strings.Repeat("-", 45))
-
-	for _, domain := range p.domains {
-		fmt.Printf("%-30s %10d\n", domain, p.sum[domain].visits)
-	}
-	fmt.Printf("\n%-30s %10d\n", "TOTAL", p.total)
-}
-
-// err returns the last error encountered
-func (p *parser) err() error {
-	return p.lerr
-}