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use percent_encoding::{utf8_percent_encode, NON_ALPHANUMERIC};
// -----------------------------------------------------------------------------
impl crate::traits::QueryString for crate::roads::nearest_roads::Request<'_> {
/// Builds the URL [query string](https://en.wikipedia.org/wiki/Query_string)
/// for the HTTP [GET](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/GET)
/// request. The query string is generated from the data found in this
/// `Request` structure.
///
/// ## Arguments
///
/// This method accepts no arguments.
///
/// ## Notes
///
/// * This function does not validate the request before generating the
/// _query string_. However, the superior method that generates the _query
/// URL_ does perform validation.
///
/// * The query string is the part of the URL after the `?` question mark.
/// For example, in the URL `https://example.com/over/there?name=ferret`
/// the query string is `name=ferret`
///
/// * There's no benefit to working on an owned `Request` struct (i.e. an
/// owned `self` versus an borrowed `&self`).
/// [percent-encoding](https://crates.io/crates/percent-encoding)
/// works on borrowed UTF-8 strings. Other types, such as enums and
/// numeric values are converted into strings. Therefore no zero-copy
/// operations are possible with an owned `self`.
fn query_string(&self) -> String {
// This section builds the "required parameters" portion of the query
// string:
// Convert `Vec<LatLng>` to `String`:
let points: String = self
.points
.iter()
.map(String::from)
.collect::<Vec<String>>()
.join("|");
// URL encode path `String`:
let points: String = utf8_percent_encode(&points, NON_ALPHANUMERIC).to_string();
// Build "required parameters" portion of the query string:
let query = format!("key={key}&points={points}", key = self.client.key);
// Return built query string to caller:
query
} // fn
} // impl