How can I pass a function with arguments in map?

help
1

Hi All,

I have a map condition like below,

lines.position(|line| does_line_contain(line, "keyword"));

This works. Then I tried below and it fails,

lines.position(does_line_contain("keyword"));

Is it possible to do like this?

2

No, Rust doesn't support implicit partial application.

3

You could make a function that returns a closure, for example (essentially doing “manual” partial application):

fn does_line_contain(needle: &str) -> impl Fn(&str) -> bool + '_ {
    move |haystack| haystack.contains(needle)
}

lines.position(does_line_contain("keyword"));
2 Likes
4

Thanks! That works. Sorry for late response.

5

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