英文:
Golang: Read ints from stdin until EOF while reporting format errors
问题
nums := make([]int, 0)
{
var d int
for {
_, err := fmt.Scan(&d)
if err != nil {
break
}
nums = append(nums, d)
}
}
这段代码用于从标准输入中读取整数。但是如果标准输入看起来像 1 2 3 f4 5，nums 最终会变成 [1 2 3]，而不报告任何错误。
如何处理这种情况最好？（即，我希望从 fmt.Scan 中获得 EOF 时，循环会静默退出，但其他所有错误都应该报告）。
编辑：我只需要 io.EOF -- 我在 http://golang.org/pkg/fmt/ 上没有找到这个文档
nums := make([]int, 0)
{
var d int
for {
_, err := fmt.Scan(&d)
if err != nil {
if err != io.EOF {
log.Fatal(err)
}
break
}
nums = append(nums, d)
}
}
英文:
nums := make([]int, 0)
{
var d int
for {
_, err := fmt.Scan(&d)
if err != nil {
break
}
nums = append(nums, d)
}
}
This works to read in ints from stdin. But if stdin looks like 1 2 3 f4 5, nums will end up being [1 2 3] without reporting any error.
What's the best way of handling this? (Ie, I want EOF from fmt.Scan to silently exit the loop, but all other errors should be reported).
edit: io.EOF was all I needed -- I hadn't found that documented at http://golang.org/pkg/fmt/
nums := make([]int, 0)
{
var d int
for {
_, err := fmt.Scan(&d)
if err != nil {
if err != io.EOF {
log.Fatal(err)
}
break
}
nums = append(nums, d)
}
}
答案1
得分: 16
你可以这样做-当你得到一个错误的数字时，读取下一个以空格分隔的内容。设置一个标志或在出现错误时保留一个错误列表，在最后报告这些错误。
package main
import (
"bytes"
"fmt"
"io"
)
func main() {
in := bytes.NewBufferString("1 2 3 f4 5")
nums := make([]int, 0)
var d int
for i := 0; i < 10; i++ {
_, err := fmt.Fscan(in, &d)
if err == io.EOF {
break
}
if err != nil {
var s string
_, err := fmt.Fscan(in, &s)
if err != nil {
break
}
fmt.Printf("跳过错误的数字：%q\n", s)
} else {
nums = append(nums, d)
}
}
fmt.Printf("nums = %v\n", nums)
}
输出结果为：
跳过错误的数字："f4"
nums = [1 2 3 5]
英文:
You could do it like this - when you get a bad number, read the next space separated thing. Set a flag or on an error or keep a list of the errors to report at the end.
package main
import (
"bytes"
"fmt"
"io"
)
func main() {
in := bytes.NewBufferString("1 2 3 f4 5")
nums := make([]int, 0)
var d int
for i := 0; i < 10; i++ {
_, err := fmt.Fscan(in, &d)
if err == io.EOF {
break
}
if err != nil {
var s string
_, err := fmt.Fscan(in, &s)
if err != nil {
break
}
fmt.Printf("Skipping bad number: %q\n", s)
} else {
nums = append(nums, d)
}
}
fmt.Printf("nums = %v\n", nums)
}
Which prints
Skipping bad number: "f4"
nums = [1 2 3 5]
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