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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /vendor/nom/src/branch/mod.rs
parentInitial commit. (diff)
downloadrustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz
rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/nom/src/branch/mod.rs')
-rw-r--r--vendor/nom/src/branch/mod.rs291
1 files changed, 291 insertions, 0 deletions
diff --git a/vendor/nom/src/branch/mod.rs b/vendor/nom/src/branch/mod.rs
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+//! Choice combinators
+
+macro_rules! succ (
+ (0, $submac:ident ! ($($rest:tt)*)) => ($submac!(1, $($rest)*));
+ (1, $submac:ident ! ($($rest:tt)*)) => ($submac!(2, $($rest)*));
+ (2, $submac:ident ! ($($rest:tt)*)) => ($submac!(3, $($rest)*));
+ (3, $submac:ident ! ($($rest:tt)*)) => ($submac!(4, $($rest)*));
+ (4, $submac:ident ! ($($rest:tt)*)) => ($submac!(5, $($rest)*));
+ (5, $submac:ident ! ($($rest:tt)*)) => ($submac!(6, $($rest)*));
+ (6, $submac:ident ! ($($rest:tt)*)) => ($submac!(7, $($rest)*));
+ (7, $submac:ident ! ($($rest:tt)*)) => ($submac!(8, $($rest)*));
+ (8, $submac:ident ! ($($rest:tt)*)) => ($submac!(9, $($rest)*));
+ (9, $submac:ident ! ($($rest:tt)*)) => ($submac!(10, $($rest)*));
+ (10, $submac:ident ! ($($rest:tt)*)) => ($submac!(11, $($rest)*));
+ (11, $submac:ident ! ($($rest:tt)*)) => ($submac!(12, $($rest)*));
+ (12, $submac:ident ! ($($rest:tt)*)) => ($submac!(13, $($rest)*));
+ (13, $submac:ident ! ($($rest:tt)*)) => ($submac!(14, $($rest)*));
+ (14, $submac:ident ! ($($rest:tt)*)) => ($submac!(15, $($rest)*));
+ (15, $submac:ident ! ($($rest:tt)*)) => ($submac!(16, $($rest)*));
+ (16, $submac:ident ! ($($rest:tt)*)) => ($submac!(17, $($rest)*));
+ (17, $submac:ident ! ($($rest:tt)*)) => ($submac!(18, $($rest)*));
+ (18, $submac:ident ! ($($rest:tt)*)) => ($submac!(19, $($rest)*));
+ (19, $submac:ident ! ($($rest:tt)*)) => ($submac!(20, $($rest)*));
+ (20, $submac:ident ! ($($rest:tt)*)) => ($submac!(21, $($rest)*));
+);
+
+#[cfg(test)]
+mod tests;
+
+use crate::error::ErrorKind;
+use crate::error::ParseError;
+use crate::internal::{Err, IResult, Parser};
+
+/// Helper trait for the [alt()] combinator.
+///
+/// This trait is implemented for tuples of up to 21 elements
+pub trait Alt<I, O, E> {
+ /// Tests each parser in the tuple and returns the result of the first one that succeeds
+ fn choice(&mut self, input: I) -> IResult<I, O, E>;
+}
+
+/// Tests a list of parsers one by one until one succeeds.
+///
+/// It takes as argument a tuple of parsers. There is a maximum of 21
+/// parsers. If you need more, it is possible to nest them in other `alt` calls,
+/// like this: `alt(parser_a, alt(parser_b, parser_c))`
+///
+/// ```rust
+/// # use nom::error_position;
+/// # use nom::{Err,error::ErrorKind, Needed, IResult};
+/// use nom::character::complete::{alpha1, digit1};
+/// use nom::branch::alt;
+/// # fn main() {
+/// fn parser(input: &str) -> IResult<&str, &str> {
+/// alt((alpha1, digit1))(input)
+/// };
+///
+/// // the first parser, alpha1, recognizes the input
+/// assert_eq!(parser("abc"), Ok(("", "abc")));
+///
+/// // the first parser returns an error, so alt tries the second one
+/// assert_eq!(parser("123456"), Ok(("", "123456")));
+///
+/// // both parsers failed, and with the default error type, alt will return the last error
+/// assert_eq!(parser(" "), Err(Err::Error(error_position!(" ", ErrorKind::Digit))));
+/// # }
+/// ```
+///
+/// With a custom error type, it is possible to have alt return the error of the parser
+/// that went the farthest in the input data
+pub fn alt<I: Clone, O, E: ParseError<I>, List: Alt<I, O, E>>(
+ mut l: List,
+) -> impl FnMut(I) -> IResult<I, O, E> {
+ move |i: I| l.choice(i)
+}
+
+/// Helper trait for the [permutation()] combinator.
+///
+/// This trait is implemented for tuples of up to 21 elements
+pub trait Permutation<I, O, E> {
+ /// Tries to apply all parsers in the tuple in various orders until all of them succeed
+ fn permutation(&mut self, input: I) -> IResult<I, O, E>;
+}
+
+/// Applies a list of parsers in any order.
+///
+/// Permutation will succeed if all of the child parsers succeeded.
+/// It takes as argument a tuple of parsers, and returns a
+/// tuple of the parser results.
+///
+/// ```rust
+/// # use nom::{Err,error::{Error, ErrorKind}, Needed, IResult};
+/// use nom::character::complete::{alpha1, digit1};
+/// use nom::branch::permutation;
+/// # fn main() {
+/// fn parser(input: &str) -> IResult<&str, (&str, &str)> {
+/// permutation((alpha1, digit1))(input)
+/// }
+///
+/// // permutation recognizes alphabetic characters then digit
+/// assert_eq!(parser("abc123"), Ok(("", ("abc", "123"))));
+///
+/// // but also in inverse order
+/// assert_eq!(parser("123abc"), Ok(("", ("abc", "123"))));
+///
+/// // it will fail if one of the parsers failed
+/// assert_eq!(parser("abc;"), Err(Err::Error(Error::new(";", ErrorKind::Digit))));
+/// # }
+/// ```
+///
+/// The parsers are applied greedily: if there are multiple unapplied parsers
+/// that could parse the next slice of input, the first one is used.
+/// ```rust
+/// # use nom::{Err, error::{Error, ErrorKind}, IResult};
+/// use nom::branch::permutation;
+/// use nom::character::complete::{anychar, char};
+///
+/// fn parser(input: &str) -> IResult<&str, (char, char)> {
+/// permutation((anychar, char('a')))(input)
+/// }
+///
+/// // anychar parses 'b', then char('a') parses 'a'
+/// assert_eq!(parser("ba"), Ok(("", ('b', 'a'))));
+///
+/// // anychar parses 'a', then char('a') fails on 'b',
+/// // even though char('a') followed by anychar would succeed
+/// assert_eq!(parser("ab"), Err(Err::Error(Error::new("b", ErrorKind::Char))));
+/// ```
+///
+pub fn permutation<I: Clone, O, E: ParseError<I>, List: Permutation<I, O, E>>(
+ mut l: List,
+) -> impl FnMut(I) -> IResult<I, O, E> {
+ move |i: I| l.permutation(i)
+}
+
+macro_rules! alt_trait(
+ ($first:ident $second:ident $($id: ident)+) => (
+ alt_trait!(__impl $first $second; $($id)+);
+ );
+ (__impl $($current:ident)*; $head:ident $($id: ident)+) => (
+ alt_trait_impl!($($current)*);
+
+ alt_trait!(__impl $($current)* $head; $($id)+);
+ );
+ (__impl $($current:ident)*; $head:ident) => (
+ alt_trait_impl!($($current)*);
+ alt_trait_impl!($($current)* $head);
+ );
+);
+
+macro_rules! alt_trait_impl(
+ ($($id:ident)+) => (
+ impl<
+ Input: Clone, Output, Error: ParseError<Input>,
+ $($id: Parser<Input, Output, Error>),+
+ > Alt<Input, Output, Error> for ( $($id),+ ) {
+
+ fn choice(&mut self, input: Input) -> IResult<Input, Output, Error> {
+ match self.0.parse(input.clone()) {
+ Err(Err::Error(e)) => alt_trait_inner!(1, self, input, e, $($id)+),
+ res => res,
+ }
+ }
+ }
+ );
+);
+
+macro_rules! alt_trait_inner(
+ ($it:tt, $self:expr, $input:expr, $err:expr, $head:ident $($id:ident)+) => (
+ match $self.$it.parse($input.clone()) {
+ Err(Err::Error(e)) => {
+ let err = $err.or(e);
+ succ!($it, alt_trait_inner!($self, $input, err, $($id)+))
+ }
+ res => res,
+ }
+ );
+ ($it:tt, $self:expr, $input:expr, $err:expr, $head:ident) => (
+ Err(Err::Error(Error::append($input, ErrorKind::Alt, $err)))
+ );
+);
+
+alt_trait!(A B C D E F G H I J K L M N O P Q R S T U);
+
+// Manually implement Alt for (A,), the 1-tuple type
+impl<Input, Output, Error: ParseError<Input>, A: Parser<Input, Output, Error>>
+ Alt<Input, Output, Error> for (A,)
+{
+ fn choice(&mut self, input: Input) -> IResult<Input, Output, Error> {
+ self.0.parse(input)
+ }
+}
+
+macro_rules! permutation_trait(
+ (
+ $name1:ident $ty1:ident $item1:ident
+ $name2:ident $ty2:ident $item2:ident
+ $($name3:ident $ty3:ident $item3:ident)*
+ ) => (
+ permutation_trait!(__impl $name1 $ty1 $item1, $name2 $ty2 $item2; $($name3 $ty3 $item3)*);
+ );
+ (
+ __impl $($name:ident $ty:ident $item:ident),+;
+ $name1:ident $ty1:ident $item1:ident $($name2:ident $ty2:ident $item2:ident)*
+ ) => (
+ permutation_trait_impl!($($name $ty $item),+);
+ permutation_trait!(__impl $($name $ty $item),+ , $name1 $ty1 $item1; $($name2 $ty2 $item2)*);
+ );
+ (__impl $($name:ident $ty:ident $item:ident),+;) => (
+ permutation_trait_impl!($($name $ty $item),+);
+ );
+);
+
+macro_rules! permutation_trait_impl(
+ ($($name:ident $ty:ident $item:ident),+) => (
+ impl<
+ Input: Clone, $($ty),+ , Error: ParseError<Input>,
+ $($name: Parser<Input, $ty, Error>),+
+ > Permutation<Input, ( $($ty),+ ), Error> for ( $($name),+ ) {
+
+ fn permutation(&mut self, mut input: Input) -> IResult<Input, ( $($ty),+ ), Error> {
+ let mut res = ($(Option::<$ty>::None),+);
+
+ loop {
+ let mut err: Option<Error> = None;
+ permutation_trait_inner!(0, self, input, res, err, $($name)+);
+
+ // If we reach here, every iterator has either been applied before,
+ // or errored on the remaining input
+ if let Some(err) = err {
+ // There are remaining parsers, and all errored on the remaining input
+ return Err(Err::Error(Error::append(input, ErrorKind::Permutation, err)));
+ }
+
+ // All parsers were applied
+ match res {
+ ($(Some($item)),+) => return Ok((input, ($($item),+))),
+ _ => unreachable!(),
+ }
+ }
+ }
+ }
+ );
+);
+
+macro_rules! permutation_trait_inner(
+ ($it:tt, $self:expr, $input:ident, $res:expr, $err:expr, $head:ident $($id:ident)*) => (
+ if $res.$it.is_none() {
+ match $self.$it.parse($input.clone()) {
+ Ok((i, o)) => {
+ $input = i;
+ $res.$it = Some(o);
+ continue;
+ }
+ Err(Err::Error(e)) => {
+ $err = Some(match $err {
+ Some(err) => err.or(e),
+ None => e,
+ });
+ }
+ Err(e) => return Err(e),
+ };
+ }
+ succ!($it, permutation_trait_inner!($self, $input, $res, $err, $($id)*));
+ );
+ ($it:tt, $self:expr, $input:ident, $res:expr, $err:expr,) => ();
+);
+
+permutation_trait!(
+ FnA A a
+ FnB B b
+ FnC C c
+ FnD D d
+ FnE E e
+ FnF F f
+ FnG G g
+ FnH H h
+ FnI I i
+ FnJ J j
+ FnK K k
+ FnL L l
+ FnM M m
+ FnN N n
+ FnO O o
+ FnP P p
+ FnQ Q q
+ FnR R r
+ FnS S s
+ FnT T t
+ FnU U u
+);