Re: Lock code block without explicit lock variable ?

[jackhftang]

The effect is like this example written in vlang, which has a lock section to 
prevent race on cursor
    
    
    const STORIES_URL = 'https://hacker-news.firebaseio.com/v0/topstories.json'
    const ITEM_URL_BASE = 'https://hacker-news.firebaseio.com/v0/item'
    
    struct Story {
        title string
    }
    
    fn main() {
        resp := http.get(STORIES_URL)?
        ids := json.decode([]int, resp.body)?
        mut cursor := 0
        for _ in 0..8 {
            go fn() {
                for {
                    lock {
                        if cursor >= ids.len {
                            break
                        }
                        id := ids[cursor]
                        cursor++
                    }
                    resp := http.get('$ITEM_URL_BASE/$id.json')?
                    story := json.decode(Story, resp.body)?
                    println(story.title)
                }
            }()
        }
        runtime.wait()
    }
    
    
    Run