Code review for str split

code review
1

Here's my code

struct Split<'reminder, 'delimiter> {
    reminder: &'reminder str,
    delimiter: &'delimiter str,
}

impl<'reminder, 'delimiter> Split<'reminder, 'delimiter> {
    pub fn new(reminder: &'reminder str,
               delimiter: &'delimiter str,) -> Self {
        if let Some(index) = reminder.find(delimiter) {
            //it is to check if the delimiter appears in the first character
            if index == 0 {
                //then remove that character
                return Split { reminder: &reminder[(delimiter.len())..], delimiter };
            }
        }
        Split { reminder, delimiter }
    }
}

impl<'reminder, 'delimiter> Iterator for Split<'reminder, 'delimiter> {
    type Item = &'reminder str;

    fn next(&mut self) -> Option<Self::Item> {
        if self.reminder.is_empty() {
            None
        } else if let Some(index) = self.reminder.find(self.delimiter) {
            let until_delimiter = &self.reminder[..index];
            self.reminder = &self.reminder[(index+ self.delimiter.len())..];
            Some(until_delimiter)
        } else {
            let val = Some(self.reminder);
            self.reminder = "";
            val
        }
    }
}

#[cfg(test)]
pub mod tests {
    use super::Split;
    #[test]
    fn basics() {
        let arr: Vec<&str> = Split::new("👍👍abc👍👍cde👍def👍", "👍").collect();
        assert_eq!(arr, vec! ["", "abc", "", "cde", "def"]);
    }
}

I tried moving the logic of checking if the first character is a delimiter to impl block. but, I'm finding it really hard. Whatever solution I come up with either looks very ugly, or fail the test case. So, how to do it so it would fit nicely with other conditions?

2

I think you need the explicit return because there is no else clause.

You can perhaps move the logic of checking if the first character is a delimiter into the impl block of Iterator

3

A block consists of a sequence of statements optionally followed an expression. There are two ways that a function can return:

  • when an explicit return expression is evaluated, it directly returns the relevant value;

  • when control flow falls to the end of the function, the result of the trailing expression in the function body is returned (or () if there is no trailing expression).

1 Like
4

I tried moving the first character logic to impl block. but, I'm finding it really hard. Whatever solution I come up with either looks very ugly, or fail the test case. I'm kind of stuck there. I'll update the above topic to reflect the issue

5

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