Todo Summary - Swift Programming

A todo summary filters task records and prints the matching names.

Summarize visible tasks

showDone showDone = false (default)showDone = true

todo_summary.swift

Replay: real traced execution (multi-file project)

let showDone = false
let tasks = [
    (name: "write", done: false),
    (name: "review", done: true),
    (name: "publish", done: false)
]
var visible: [String] = []

for task in tasks {
    if showDone || !task.done {
        visible.append(task.name)
    }
}

let summary = visible.joined(separator: ",")

print(summary)

let showDone = true
let tasks = [
    (name: "write", done: false),
    (name: "review", done: true),
    (name: "publish", done: false)
]
var visible: [String] = []

for task in tasks {
    if showDone || !task.done {
        visible.append(task.name)
    }
}

let summary = visible.joined(separator: ",")

print(summary)

showDone ← false, tasks ← [(name: "write", done: false), (name: "review", done: true), (name: "publish", done: false)]

1let showDone→ false = false  //@showDone=true2let tasks→ [(name: "write", done: false), (name: "review", done: true), (name: "publish", done: false)] = [3    (name: "write", done: false),4    (name: "review", done: true),5    (name: "publish", done: false)6]7var visible→ []: [String] = []⋯

for task in tasks

pass 1 of 3

⋯9for task(name: "write", done: false) in tasks[(name: "write", done: false), (name: "review", done: true), (name: "publish", done: false)] {10    if showDone || !task.done {⋯

All 3 passes — pass 1 is the card above
pass	`task`	`showDone`	`task.done`	`visible`	`task.name`
1	(name: "write", done: false)	false	false	[]	write
2	(name: "review", done: true)	—	—	—	—
3	(name: "publish", done: false)	false	false	["write"]	publish

if showDone || !task.done

pass 1 of 2

⋯9for task in tasks {10    if showDonefalse || !task.donefalse {11        visible[].append(task.namewrite)12    }⋯

if showDone || !task.done

pass 2 of 2

⋯9for task in tasks {10    if showDonefalse || !task.donefalse {11        visible["write"].append(task.namepublish)12    }⋯

summary ← write,publish

⋯15let summary→ write,publish = visible["write", "publish"].joined(separator: ",")1617print(summarywrite,publish)⋯

outputwrite,publish

showDone ← true, tasks ← [(name: "write", done: false), (name: "review", done: true), (name: "publish", done: false)]

1let showDone→ true = true2let tasks→ [(name: "write", done: false), (name: "review", done: true), (name: "publish", done: false)] = [3    (name: "write", done: false),4    (name: "review", done: true),5    (name: "publish", done: false)6]7var visible→ []: [String] = []⋯

for task in tasks

pass 1 of 3

⋯9for task(name: "write", done: false) in tasks[(name: "write", done: false), (name: "review", done: true), (name: "publish", done: false)] {10    if showDone || !task.done {⋯

All 3 passes — pass 1 is the card above
pass	`task`
1	(name: "write", done: false)
2	(name: "review", done: true)
3	(name: "publish", done: false)

3
if showDone || !task.done
pass 1 of 3
```
⋯9for task in tasks {10    if showDonetrue || !task.donefalse {11        visible[].append(task.namewrite)12    }⋯
```
All 3 passes — pass 1 is the card above
pass task.done visible task.name
1 false [] write
2 true ["write"] review
3 false ["write", "review"] publish

All 3 passes — pass 1 is the card above
pass	`task.done`	`visible`	`task.name`
1	false	[]	write
2	true	["write"]	review
3	false	["write", "review"]	publish

summary ← write,review,publish

⋯15let summary→ write,review,publish = visible["write", "review", "publish"].joined(separator: ",")1617print(summarywrite,review,publish)⋯

outputwrite,review,publish

task filter Filtering a small list is a common program shape: inspect each record, keep the ones that match, and print a compact summary.