fn deserialize()

in elasticsearch/src/params.rs [431:491]
54 lines of code
4 McCabe index (conditional complexity)

    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        struct SlicesVisitor;

        impl<'de> Visitor<'de> for SlicesVisitor {
            type Value = Slices;

            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
                write!(formatter, "expected integer or string")
            }

            fn visit_i64<E>(self, value: i64) -> Result<Self::Value, E>
            where
                E: de::Error,
            {
                if value <= i32::MAX as i64 {
                    Ok(Slices::Count(value as i32))
                } else {
                    Err(E::custom(format!("i32 out of range: {}", value)))
                }
            }

            fn visit_u64<E>(self, value: u64) -> Result<Self::Value, E>
            where
                E: de::Error,
            {
                if value <= i32::MAX as u64 {
                    Ok(Slices::Count(value as i32))
                } else {
                    Err(E::custom(format!("i32 out of range: {}", value)))
                }
            }

            fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
            where
                E: de::Error,
            {
                match value {
                    "auto" => Ok(Slices::Auto),
                    n => match n.parse::<i32>() {
                        Ok(i) => Ok(Slices::Count(i)),
                        Err(_) => Err(E::custom(format!(
                            "expected 'auto' or i32 but received: {}",
                            n
                        ))),
                    },
                }
            }

            fn visit_string<E>(self, value: String) -> Result<Self::Value, E>
            where
                E: de::Error,
            {
                self.visit_str(&value)
            }
        }

        deserializer.deserialize_any(SlicesVisitor)
    }