在Go中匹配段落

Question

I'm a Go beginner. I'm trying to match paragraphs with regexp:

package main

import (
    "fmt"
    "regexp"
)

func main() {
    str := `first paragraph

second paragraph

third paragraph`

    r, _ := regexp.Compile(`(.+)(

)`)

    fmt.Println(r.FindAllString(str, -1))
}

The output is this:

[first paragraph

 second paragraph

]

I think it's matching the empty lines also. I only want to match the paragraphs (first paragraph, second paragraph).

How to modify my code to accomplish that?

Answer 1

You can try, using a re2-compliant regexp, (?s).*?( |$) (see playground example):

package main

import (
    "fmt"
    "regexp"
)

func main() {
    str := `first paragraph
second line of first paragraph

second paragraph

third paragraph
second line of third paragraph`

    r, _ := regexp.Compile(`(?s).*?(

|$)`)

    res := r.FindAllString(str, -1)
    fmt.Printf("%+v %d", res, len(res))
}

That would output:

[first paragraph
second line of first paragraph

 second paragraph

 third paragraph
second line of third paragraph] 3