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doc: improve examples

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This commit is contained in:
Samuel Berthe
2026-03-01 21:25:04 +01:00
parent ff0e293ce3
commit 6f42e74a11
3 changed files with 175 additions and 111 deletions
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lo_example_test.go
+166 -105
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@@ -1250,11 +1250,14 @@ func ExampleFindDuplicatesByErr() {
}
result, err := FindDuplicatesByErr(users, func(user User) (int, error) {
if user.Name == "Charlie" {
return 0, fmt.Errorf("charlie is not allowed")
}
return user.Age, nil
})
fmt.Printf("%d %v", len(result), err)
// Output: 2 <nil>
// Output: 0 charlie is not allowed
}
func ExampleMin() {
@@ -1326,11 +1329,14 @@ func ExampleMinByErr() {
}
result, err := MinByErr(users, func(a, b User) (bool, error) {
if a.Name == "Bob" {
return false, fmt.Errorf("bob is not allowed")
}
return a.Age < b.Age, nil
})
fmt.Printf("%s %v", result.Name, err)
// Output: Alice <nil>
fmt.Printf("%v %v", result.Name, err)
// Output: bob is not allowed
}
func ExampleMinIndexBy() {
@@ -1365,12 +1371,15 @@ func ExampleMinIndexByErr() {
{Name: "Charlie", Age: 35},
}
result, index, err := MinIndexByErr(users, func(a, b User) (bool, error) {
result, _, err := MinIndexByErr(users, func(a, b User) (bool, error) {
if a.Name == "Bob" {
return false, fmt.Errorf("bob is not allowed")
}
return a.Age < b.Age, nil
})
fmt.Printf("%s %d %v", result.Name, index, err)
// Output: Alice 0 <nil>
fmt.Printf("%v %v", result.Name, err)
// Output: bob is not allowed
}
func ExampleEarliest() {
@@ -1418,12 +1427,15 @@ func ExampleEarliestByErr() {
{Name: "Event C", Time: now.Add(-time.Hour)},
}
result, err := EarliestByErr(events, func(event Event) (time.Time, error) {
_, err := EarliestByErr(events, func(event Event) (time.Time, error) {
if event.Name == "Event B" {
return time.Time{}, fmt.Errorf("event b is not allowed")
}
return event.Time, nil
})
fmt.Printf("%s %v", result.Name, err)
// Output: Event C <nil>
fmt.Printf("%v", err)
// Output: event b is not allowed
}
func ExampleMax() {
@@ -1494,12 +1506,15 @@ func ExampleMaxByErr() {
{Name: "Charlie", Age: 35},
}
result, err := MaxByErr(users, func(a, b User) (bool, error) {
_, err := MaxByErr(users, func(a, b User) (bool, error) {
if b.Name == "Bob" {
return false, fmt.Errorf("bob is not allowed")
}
return a.Age > b.Age, nil
})
fmt.Printf("%s %v", result.Name, err)
// Output: Charlie <nil>
fmt.Printf("%v", err)
// Output: bob is not allowed
}
func ExampleMaxIndexBy() {
@@ -1534,12 +1549,15 @@ func ExampleMaxIndexByErr() {
{Name: "Charlie", Age: 35},
}
result, index, err := MaxIndexByErr(users, func(a, b User) (bool, error) {
_, _, err := MaxIndexByErr(users, func(a, b User) (bool, error) {
if b.Name == "Bob" {
return false, fmt.Errorf("bob is not allowed")
}
return a.Age > b.Age, nil
})
fmt.Printf("%s %d %v", result.Name, index, err)
// Output: Charlie 2 <nil>
fmt.Printf("%v", err)
// Output: bob is not allowed
}
func ExampleLatest() {
@@ -1584,19 +1602,19 @@ func ExampleLatestByErr() {
now := time.Now()
events := []Event{
{Name: "Event A", Time: now.Add(time.Hour), Err: nil},
{Name: "Event B", Time: now, Err: nil},
{Name: "Event B", Time: now, Err: fmt.Errorf("event b error")},
{Name: "Event C", Time: now.Add(-time.Hour), Err: nil},
}
result, err := LatestByErr(events, func(event Event) (time.Time, error) {
_, err := LatestByErr(events, func(event Event) (time.Time, error) {
if event.Err != nil {
return time.Time{}, event.Err
}
return event.Time, nil
})
fmt.Printf("%s %v", result.Name, err)
// Output: Event A <nil>
fmt.Printf("%v", err)
// Output: event b error
}
func ExampleFirst() {
@@ -1816,6 +1834,9 @@ func ExampleWithoutByErr() {
// extract function to get the user ID
extractID := func(user User) (int, error) {
if user.ID == 2 {
return 0, fmt.Errorf("user 2 extraction failed")
}
return user.ID, nil
}
@@ -1825,7 +1846,7 @@ func ExampleWithoutByErr() {
// output the filtered users
fmt.Printf("%v %v", filteredUsers, err)
// Output:
// [{1 Alice}] <nil>
// [] user 2 extraction failed
}
func ExampleKeys() {
@@ -1894,12 +1915,15 @@ func ExamplePickBy() {
func ExamplePickByErr() {
kv := map[string]int{"foo": 1, "bar": 2, "baz": 3}
result, err := PickByErr(kv, func(key string, value int) (bool, error) {
_, err := PickByErr(kv, func(key string, value int) (bool, error) {
if key == "bar" {
return false, fmt.Errorf("key bar is not allowed")
}
return value%2 == 1, nil
})
fmt.Printf("%v %v %v %v", len(result), result["foo"], result["baz"], err)
// Output: 2 1 3 <nil>
fmt.Printf("%v", err)
// Output: key bar is not allowed
}
func ExamplePickByKeys() {
@@ -1934,12 +1958,15 @@ func ExampleOmitBy() {
func ExampleOmitByErr() {
kv := map[string]int{"foo": 1, "bar": 2, "baz": 3}
result, err := OmitByErr(kv, func(key string, value int) (bool, error) {
_, err := OmitByErr(kv, func(key string, value int) (bool, error) {
if key == "bar" {
return false, fmt.Errorf("key bar is not allowed")
}
return value%2 == 1, nil
})
fmt.Printf("%v %v", result, err)
// Output: map[bar:2] <nil>
fmt.Printf("%v", err)
// Output: key bar is not allowed
}
func ExampleOmitByKeys() {
@@ -2045,12 +2072,15 @@ func ExampleMapKeys() {
func ExampleMapKeysErr() {
kv := map[int]int{1: 1, 2: 2, 3: 3, 4: 4}
result, err := MapKeysErr(kv, func(_, k int) (string, error) {
_, err := MapKeysErr(kv, func(_, k int) (string, error) {
if k == 3 {
return "", fmt.Errorf("key 3 is not allowed")
}
return strconv.FormatInt(int64(k), 10), nil
})
fmt.Printf("%v %v %v %v %v %v", len(result), result["1"], result["2"], result["3"], result["4"], err)
// Output: 4 1 2 3 4 <nil>
fmt.Printf("%v", err)
// Output: key 3 is not allowed
}
func ExampleMapValues() {
@@ -2067,12 +2097,15 @@ func ExampleMapValues() {
func ExampleMapValuesErr() {
kv := map[int]int{1: 1, 2: 2, 3: 3, 4: 4}
result, err := MapValuesErr(kv, func(v, _ int) (string, error) {
_, err := MapValuesErr(kv, func(v, _ int) (string, error) {
if v == 3 {
return "", fmt.Errorf("value 3 is not allowed")
}
return strconv.FormatInt(int64(v), 10), nil
})
fmt.Printf("%v %q %q %q %q %v", len(result), result[1], result[2], result[3], result[4], err)
// Output: 4 "1" "2" "3" "4" <nil>
fmt.Printf("%v", err)
// Output: value 3 is not allowed
}
func ExampleMapEntries() {
@@ -2089,12 +2122,15 @@ func ExampleMapEntries() {
func ExampleMapEntriesErr() {
kv := map[string]int{"foo": 1, "bar": 2}
result, err := MapEntriesErr(kv, func(k string, v int) (int, string, error) {
_, err := MapEntriesErr(kv, func(k string, v int) (int, string, error) {
if k == "foo" {
return 0, "", fmt.Errorf("entry foo is not allowed")
}
return v, k, nil
})
fmt.Printf("%v %v", result, err)
// Output: map[1:foo 2:bar] <nil>
fmt.Printf("%v", err)
// Output: entry foo is not allowed
}
func ExampleMapToSlice() {
@@ -2112,13 +2148,15 @@ func ExampleMapToSlice() {
func ExampleMapToSliceErr() {
kv := map[int]int64{1: 1, 2: 2, 3: 3, 4: 4}
result, err := MapToSliceErr(kv, func(k int, v int64) (string, error) {
_, err := MapToSliceErr(kv, func(k int, v int64) (string, error) {
if k == 3 {
return "", fmt.Errorf("key 3 is not allowed")
}
return fmt.Sprintf("%d_%d", k, v), nil
})
sort.Strings(result)
fmt.Printf("%v %v", result, err)
// Output: [1_1 2_2 3_3 4_4] <nil>
fmt.Printf("%v", err)
// Output: key 3 is not allowed
}
func ExampleFilterMapToSlice() {
@@ -2136,13 +2174,15 @@ func ExampleFilterMapToSlice() {
func ExampleFilterMapToSliceErr() {
kv := map[int]int64{1: 1, 2: 2, 3: 3, 4: 4}
result, err := FilterMapToSliceErr(kv, func(k int, v int64) (string, bool, error) {
_, err := FilterMapToSliceErr(kv, func(k int, v int64) (string, bool, error) {
if k == 3 {
return "", false, fmt.Errorf("key 3 is not allowed")
}
return fmt.Sprintf("%d_%d", k, v), k%2 == 0, nil
})
sort.Strings(result)
fmt.Printf("%v %v", result, err)
// Output: [2_2 4_4] <nil>
fmt.Printf("%v", err)
// Output: key 3 is not allowed
}
func ExampleFilterKeys() {
@@ -2271,14 +2311,17 @@ func ExampleSumBy() {
}
func ExampleSumByErr() {
list := []string{"foo", "bar"}
list := []string{"foo", "bar", "baz"}
result, err := SumByErr(list, func(item string) (int, error) {
_, err := SumByErr(list, func(item string) (int, error) {
if item == "bar" {
return 0, fmt.Errorf("bar is not allowed")
}
return len(item), nil
})
fmt.Printf("%v %v", result, err)
// Output: 6 <nil>
fmt.Printf("%v", err)
// Output: bar is not allowed
}
func ExampleProduct() {
@@ -2302,14 +2345,17 @@ func ExampleProductBy() {
}
func ExampleProductByErr() {
list := []string{"foo", "bar"}
list := []string{"foo", "bar", "baz"}
result, err := ProductByErr(list, func(item string) (int, error) {
_, err := ProductByErr(list, func(item string) (int, error) {
if item == "bar" {
return 0, fmt.Errorf("bar is not allowed")
}
return len(item), nil
})
fmt.Printf("%v %v", result, err)
// Output: 9 <nil>
fmt.Printf("%v", err)
// Output: bar is not allowed
}
func ExampleMean() {
@@ -2333,14 +2379,17 @@ func ExampleMeanBy() {
}
func ExampleMeanByErr() {
list := []string{"foo", "bar"}
list := []string{"foo", "bar", "baz"}
result, err := MeanByErr(list, func(item string) (int, error) {
_, err := MeanByErr(list, func(item string) (int, error) {
if item == "bar" {
return 0, fmt.Errorf("bar is not allowed")
}
return len(item), nil
})
fmt.Printf("%v %v", result, err)
// Output: 3 <nil>
fmt.Printf("%v", err)
// Output: bar is not allowed
}
func ExampleFilter() {
@@ -2388,12 +2437,15 @@ func ExampleMap() {
func ExampleMapErr() {
list := []int64{1, 2, 3, 4}
result, err := MapErr(list, func(nbr int64, index int) (string, error) {
_, err := MapErr(list, func(nbr int64, index int) (string, error) {
if nbr == 3 {
return "", fmt.Errorf("number 3 is not allowed")
}
return strconv.FormatInt(nbr*2, 10), nil
})
fmt.Printf("%v %v", result, err)
// Output: [2 4 6 8] <nil>
fmt.Printf("%v", err)
// Output: number 3 is not allowed
}
func ExampleUniqMap() {
@@ -2441,15 +2493,18 @@ func ExampleFlatMap() {
func ExampleFlatMapErr() {
list := []int64{1, 2, 3, 4}
result, err := FlatMapErr(list, func(nbr int64, index int) ([]string, error) {
_, err := FlatMapErr(list, func(nbr int64, index int) ([]string, error) {
if nbr == 3 {
return nil, fmt.Errorf("number 3 is not allowed")
}
return []string{
strconv.FormatInt(nbr, 10), // base 10
strconv.FormatInt(nbr, 2), // base 2
}, nil
})
fmt.Printf("%v %v", result, err)
// Output: [1 1 2 10 3 11 4 100] <nil>
fmt.Printf("%v", err)
// Output: number 3 is not allowed
}
func ExampleReduce() {
@@ -2466,12 +2521,15 @@ func ExampleReduce() {
func ExampleReduceErr() {
list := []int64{1, 2, 3, 4}
result, err := ReduceErr(list, func(agg, item int64, index int) (int64, error) {
_, err := ReduceErr(list, func(agg, item int64, index int) (int64, error) {
if item == 3 {
return 0, fmt.Errorf("number 3 is not allowed")
}
return agg + item, nil
}, 0)
fmt.Printf("%v %v", result, err)
// Output: 10 <nil>
fmt.Printf("%v", err)
// Output: number 3 is not allowed
}
func ExampleReduceRight() {
@@ -2488,12 +2546,15 @@ func ExampleReduceRight() {
func ExampleReduceRightErr() {
list := [][]int{{0, 1}, {2, 3}, {4, 5}}
result, err := ReduceRightErr(list, func(agg, item []int, index int) ([]int, error) {
_, err := ReduceRightErr(list, func(agg, item []int, index int) ([]int, error) {
if index == 0 {
return nil, fmt.Errorf("index 0 is not allowed")
}
return append(agg, item...), nil
}, []int{})
fmt.Printf("%v %v", result, err)
// Output: [4 5 2 3 0 1] <nil>
fmt.Printf("%v", err)
// Output: index 0 is not allowed
}
func ExampleForEach() {
@@ -2558,12 +2619,15 @@ func ExampleUniqBy() {
func ExampleUniqByErr() {
list := []int{0, 1, 2, 3, 4, 5}
result, err := UniqByErr(list, func(i int) (int, error) {
_, err := UniqByErr(list, func(i int) (int, error) {
if i == 3 {
return 0, fmt.Errorf("number 3 is not allowed")
}
return i % 3, nil
})
fmt.Printf("%v %v", result, err)
// Output: [0 1 2] <nil>
fmt.Printf("%v", err)
// Output: number 3 is not allowed
}
func ExampleGroupBy() {
@@ -2585,19 +2649,15 @@ func ExampleGroupBy() {
func ExampleGroupByErr() {
list := []int{0, 1, 2, 3, 4, 5}
result, err := GroupByErr(list, func(i int) (int, error) {
_, err := GroupByErr(list, func(i int) (int, error) {
if i == 3 {
return 0, fmt.Errorf("number 3 is not allowed")
}
return i % 3, nil
})
fmt.Printf("%v\n", result[0])
fmt.Printf("%v\n", result[1])
fmt.Printf("%v\n", result[2])
fmt.Printf("%v", err)
// Output:
// [0 3]
// [1 4]
// [2 5]
// <nil>
// Output: number 3 is not allowed
}
func ExampleGroupByMap() {
@@ -2619,19 +2679,15 @@ func ExampleGroupByMap() {
func ExampleGroupByMapErr() {
list := []int{0, 1, 2, 3, 4, 5}
result, err := GroupByMapErr(list, func(i int) (int, int, error) {
_, err := GroupByMapErr(list, func(i int) (int, int, error) {
if i == 3 {
return 0, 0, fmt.Errorf("number 3 is not allowed")
}
return i % 3, i * 2, nil
})
fmt.Printf("%v\n", result[0])
fmt.Printf("%v\n", result[1])
fmt.Printf("%v\n", result[2])
fmt.Printf("%v", err)
// Output:
// [0 6]
// [2 8]
// [4 10]
// <nil>
// Output: number 3 is not allowed
}
func ExampleChunk() {
@@ -2707,7 +2763,10 @@ func ExamplePartitionBy() {
func ExamplePartitionByErr() {
list := []int{-2, -1, 0, 1, 2, 3, 4}
result, err := PartitionByErr(list, func(x int) (string, error) {
_, err := PartitionByErr(list, func(x int) (string, error) {
if x == 0 {
return "", fmt.Errorf("zero is not allowed")
}
if x < 0 {
return "negative", nil
} else if x%2 == 0 {
@@ -2716,15 +2775,8 @@ func ExamplePartitionByErr() {
return "odd", nil
})
for _, item := range result {
fmt.Printf("%v\n", item)
}
fmt.Printf("%v", err)
// Output:
// [-2 -1]
// [0 2 4]
// [1 3]
// <nil>
// Output: zero is not allowed
}
func ExampleFlatten() {
@@ -2802,12 +2854,15 @@ func ExampleRepeatBy() {
}
func ExampleRepeatByErr() {
result, err := RepeatByErr(3, func(i int) (string, error) {
result, err := RepeatByErr(5, func(i int) (string, error) {
if i == 3 {
return "", fmt.Errorf("index 3 is not allowed")
}
return fmt.Sprintf("item-%d", i), nil
})
fmt.Printf("%d %v", len(result), err)
// Output: 3 <nil>
// Output: 0 index 3 is not allowed
}
func ExampleKeyBy() {
@@ -2824,12 +2879,15 @@ func ExampleKeyBy() {
func ExampleKeyByErr() {
list := []string{"a", "aa", "aaa"}
result, err := KeyByErr(list, func(str string) (int, error) {
_, err := KeyByErr(list, func(str string) (int, error) {
if str == "aa" {
return 0, fmt.Errorf("aa is not allowed")
}
return len(str), nil
})
fmt.Printf("%v %v", result, err)
// Output: map[1:a 2:aa 3:aaa] <nil>
fmt.Printf("%v", err)
// Output: aa is not allowed
}
func ExampleSliceToMap() {
@@ -2986,12 +3044,15 @@ func ExampleCountBy() {
func ExampleCountByErr() {
list := []int{0, 1, 2, 3, 4, 5, 0, 1, 2, 3}
result, err := CountByErr(list, func(i int) (bool, error) {
_, err := CountByErr(list, func(i int) (bool, error) {
if i == 3 {
return false, fmt.Errorf("number 3 is not allowed")
}
return i < 4, nil
})
fmt.Printf("%v %v", result, err)
// Output: 8 <nil>
fmt.Printf("%v", err)
// Output: number 3 is not allowed
}
func ExampleCountValues() {