Day 035 — Week 1 Review + Recall¶

Month 2 · Week 1 · ⬅ Day 034 · Day 036 ➡ · Journal index

🎯 Learning Objective¶

Consolidate the week's standard-library I/O and text material with closed-book recall, then write the formal weekly review.

📚 Topics¶

Recap: io interfaces, bufio, os/files, fmt verbs, strings/strconv/bytes, strings.Builder

📖 Reading / Sources¶

Re-skimmed my own Day 029–034 notes
io · bufio · fmt verb tables

📝 Notes¶

This is a review day — the full writeup, re-quiz, action items, and metrics live in the week review file: week-1-review.md.
One-line theme: everything in Go is a stream of bytes, and the stdlib gives small composable interfaces (io.Reader/io.Writer) plus buffering and text tools on top.
The threads that connect the week: io.Reader/io.Writer → buffered by bufio → backed by os.File → formatted with fmt → parsed/built with strings/strconv/bytes/Builder.

💻 Code Examples¶

// The week in one pipeline: read a file, scan lines, build a result string.
f, _ := os.Open("data.txt")        // *os.File is an io.Reader (Day 031)
defer f.Close()
sc := bufio.NewScanner(f)          // buffered scanning (Day 030)
var b strings.Builder              // efficient build (Day 034)
for sc.Scan() {
    fmt.Fprintf(&b, "[%s]\n", sc.Text()) // fmt verbs (Day 032)
}
_ = b.String()

🏋️ Exercises / Practice¶

Exercise	Status	Link
Re-run all Week 1 tests	✅	`go test ./exercises/month-02/week-1/...`

🐛 Mistakes Made¶

(Review day) Consolidated this week's mistakes into the weekly review's "Weaknesses" section.

❓ Open Questions¶

Carried into the weekly review's re-quiz and next-week goals.

🧠 Active Recall (answer without looking)¶

Q: Name the two methods that define io.Reader and io.Writer.

A
`Read(p []byte) (int, error)` and `Write(p []byte) (int, error)` — one method each, which is why byte streams are interchangeable.
Q: Two stdlib gotchas from this week that silently lose data?

A
Forgetting `bufio.Writer.Flush()`, and calling `os.Exit` (which skips deferred flush/close). Both drop buffered bytes.

🪶 Feynman Reflection¶

The week clicked into one picture: a file (or socket, or string) is a byte stream behind the io.Reader/io.Writer interfaces; bufio makes streaming fast; fmt formats values into bytes; and strings/strconv/bytes/Builder parse and assemble text without wasteful copying.

🕳️ Knowledge Gaps¶

See the weekly review for the consolidated gap list heading into Week 2 (testing & tooling).

✅ Summary¶

Week 1 of Month 2 is consolidated: I can move, buffer, format, and transform bytes/text idiomatically. Details in the weekly review.

⏭️ Next Steps / Prep for Tomorrow¶

Read the week-1 review, then start Week 2: testing, table-driven tests, and go tooling.

Time spent	Difficulty	Confidence
90 min	🟦⬜⬜⬜⬜	🟦🟦🟦🟦⬜

Suggested commit: docs(journal): month 2 week 1 review and recall (day 035)