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pub mod errors;
use std::iter::Peekable;
pub use self::errors::ParserError;
use crate::subtags;
use crate::LanguageIdentifier;
pub fn parse_language_identifier_from_iter<'a>(
iter: &mut Peekable<impl Iterator<Item = &'a [u8]>>,
allow_extension: bool,
) -> Result<LanguageIdentifier, ParserError> {
let language = if let Some(subtag) = iter.next() {
subtags::Language::from_bytes(subtag)?
} else {
subtags::Language::default()
};
let mut script = None;
let mut region = None;
let mut variants = vec![];
let mut position = 1;
while let Some(subtag) = iter.peek() {
if position == 1 {
if let Ok(s) = subtags::Script::from_bytes(subtag) {
script = Some(s);
position = 2;
} else if let Ok(s) = subtags::Region::from_bytes(subtag) {
region = Some(s);
position = 3;
} else if let Ok(v) = subtags::Variant::from_bytes(subtag) {
variants.push(v);
position = 3;
} else {
break;
}
} else if position == 2 {
if let Ok(s) = subtags::Region::from_bytes(subtag) {
region = Some(s);
position = 3;
} else if let Ok(v) = subtags::Variant::from_bytes(subtag) {
variants.push(v);
position = 3;
} else {
break;
}
} else {
// Variants
if let Ok(v) = subtags::Variant::from_bytes(subtag) {
variants.push(v);
} else {
break;
}
}
iter.next();
}
if !allow_extension && iter.peek().is_some() {
return Err(ParserError::InvalidSubtag);
}
let variants = if variants.is_empty() {
None
} else {
variants.sort_unstable();
variants.dedup();
Some(variants.into_boxed_slice())
};
Ok(LanguageIdentifier {
language,
script,
region,
variants,
})
}
pub fn parse_language_identifier(t: &[u8]) -> Result<LanguageIdentifier, ParserError> {
let mut iter = t.split(|c| *c == b'-' || *c == b'_').peekable();
parse_language_identifier_from_iter(&mut iter, false)
}