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use std::fmt;
/// [SPARQL query](https://www.w3.org/TR/sparql11-query/) results serialization formats.
#[derive(Eq, PartialEq, Debug, Clone, Copy, Hash)]
#[non_exhaustive]
pub enum QueryResultsFormat {
/// [SPARQL Query Results XML Format](https://www.w3.org/TR/rdf-sparql-XMLres/)
Xml,
/// [SPARQL Query Results JSON Format](https://www.w3.org/TR/sparql11-results-json/)
Json,
/// [SPARQL Query Results CSV Format](https://www.w3.org/TR/sparql11-results-csv-tsv/)
Csv,
/// [SPARQL Query Results TSV Format](https://www.w3.org/TR/sparql11-results-csv-tsv/)
Tsv,
}
impl QueryResultsFormat {
/// The format canonical IRI according to the [Unique URIs for file formats registry](https://www.w3.org/ns/formats/).
///
/// ```
/// use sparesults::QueryResultsFormat;
///
/// assert_eq!(
/// QueryResultsFormat::Json.iri(),
/// "http://www.w3.org/ns/formats/SPARQL_Results_JSON"
/// )
/// ```
#[inline]
pub fn iri(self) -> &'static str {
match self {
Self::Xml => "http://www.w3.org/ns/formats/SPARQL_Results_XML",
Self::Json => "http://www.w3.org/ns/formats/SPARQL_Results_JSON",
Self::Csv => "http://www.w3.org/ns/formats/SPARQL_Results_CSV",
Self::Tsv => "http://www.w3.org/ns/formats/SPARQL_Results_TSV",
}
}
/// The format [IANA media type](https://tools.ietf.org/html/rfc2046).
///
/// ```
/// use sparesults::QueryResultsFormat;
///
/// assert_eq!(
/// QueryResultsFormat::Json.media_type(),
/// "application/sparql-results+json"
/// )
/// ```
#[inline]
pub fn media_type(self) -> &'static str {
match self {
Self::Xml => "application/sparql-results+xml",
Self::Json => "application/sparql-results+json",
Self::Csv => "text/csv; charset=utf-8",
Self::Tsv => "text/tab-separated-values; charset=utf-8",
}
}
/// The format [IANA-registered](https://tools.ietf.org/html/rfc2046) file extension.
///
/// ```
/// use sparesults::QueryResultsFormat;
///
/// assert_eq!(QueryResultsFormat::Json.file_extension(), "srj")
/// ```
#[inline]
pub fn file_extension(self) -> &'static str {
match self {
Self::Xml => "srx",
Self::Json => "srj",
Self::Csv => "csv",
Self::Tsv => "tsv",
}
}
/// The format name.
///
/// ```
/// use sparesults::QueryResultsFormat;
///
/// assert_eq!(QueryResultsFormat::Json.name(), "SPARQL Results in JSON")
/// ```
#[inline]
pub const fn name(self) -> &'static str {
match self {
Self::Xml => "SPARQL Results in XML",
Self::Json => "SPARQL Results in JSON",
Self::Csv => "SPARQL Results in CSV",
Self::Tsv => "SPARQL Results in TSV",
}
}
/// Looks for a known format from a media type.
///
/// It supports some media type aliases.
/// For example, "application/xml" is going to return `Xml` even if it is not its canonical media type.
///
/// Example:
/// ```
/// use sparesults::QueryResultsFormat;
///
/// assert_eq!(
/// QueryResultsFormat::from_media_type("application/sparql-results+json; charset=utf-8"),
/// Some(QueryResultsFormat::Json)
/// )
/// ```
#[inline]
pub fn from_media_type(media_type: &str) -> Option<Self> {
const MEDIA_SUBTYPES: [(&str, QueryResultsFormat); 8] = [
("csv", QueryResultsFormat::Csv),
("json", QueryResultsFormat::Json),
("plain", QueryResultsFormat::Csv),
("sparql-results+json", QueryResultsFormat::Json),
("sparql-results+xml", QueryResultsFormat::Xml),
("tab-separated-values", QueryResultsFormat::Tsv),
("tsv", QueryResultsFormat::Tsv),
("xml", QueryResultsFormat::Xml),
];
let (r#type, subtype) = media_type
.split_once(';')
.unwrap_or((media_type, ""))
.0
.trim()
.split_once('/')?;
let r#type = r#type.trim();
if !r#type.eq_ignore_ascii_case("application") && !r#type.eq_ignore_ascii_case("text") {
return None;
}
let subtype = subtype.trim();
let subtype = subtype.strip_prefix("x-").unwrap_or(subtype);
for (candidate_subtype, candidate_id) in MEDIA_SUBTYPES {
if candidate_subtype.eq_ignore_ascii_case(subtype) {
return Some(candidate_id);
}
}
None
}
/// Looks for a known format from an extension.
///
/// It supports some aliases.
///
/// Example:
/// ```
/// use sparesults::QueryResultsFormat;
///
/// assert_eq!(
/// QueryResultsFormat::from_extension("json"),
/// Some(QueryResultsFormat::Json)
/// )
/// ```
#[inline]
pub fn from_extension(extension: &str) -> Option<Self> {
const MEDIA_TYPES: [(&str, QueryResultsFormat); 7] = [
("csv", QueryResultsFormat::Csv),
("json", QueryResultsFormat::Json),
("srj", QueryResultsFormat::Json),
("srx", QueryResultsFormat::Xml),
("tsv", QueryResultsFormat::Tsv),
("txt", QueryResultsFormat::Csv),
("xml", QueryResultsFormat::Xml),
];
for (candidate_extension, candidate_id) in MEDIA_TYPES {
if candidate_extension.eq_ignore_ascii_case(extension) {
return Some(candidate_id);
}
}
None
}
}
impl fmt::Display for QueryResultsFormat {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str(self.name())
}
}