serde_at 0.18.0

use serde::de;

use crate::de::{Deserializer, Error, Result};

#[allow(clippy::module_name_repetitions)]
pub struct SeqAccess<'a, 'b> {
    first: bool,
    de: &'a mut Deserializer<'b>,
}

impl<'a, 'b> SeqAccess<'a, 'b> {
    pub(crate) fn new(de: &'a mut Deserializer<'b>) -> Self {
        SeqAccess { de, first: true }
    }
}

impl<'a, 'de> de::SeqAccess<'de> for SeqAccess<'a, 'de> {
    type Error = Error;

    fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>>
    where
        T: de::DeserializeSeed<'de>,
    {
        match self.de.parse_whitespace() {
            Some(b',') => {
                self.de.eat_char();
                self.de
                    .parse_whitespace()
                    .ok_or(Error::EofWhileParsingValue)?;
            }
            Some(c) => {
                if self.first {
                    self.first = false;
                } else if c != b'+' {
                    return Ok(None);
                }
            }
            None => {
                // No more characters!
                // Fall-through to deserialize any `Option<..>` to `None`
            }
        };

        match seed.deserialize(&mut *self.de) {
            // Misuse EofWhileParsingObject here to indicate finished object in vec cases.
            // See matching TODO in `de::mod`..
            Err(Error::EofWhileParsingObject) => Ok(None),
            Err(e) => Err(e),
            Ok(v) => Ok(Some(v)),
        }
    }
}