| //! # List of parsers and combinators |
| //! |
| //! **Note**: this list is meant to provide a nicer way to find a parser than reading through the documentation on docs.rs. Function combinators are organized in module so they are a bit easier to find. |
| //! |
| //! ## Basic elements |
| //! |
| //! Those are used to recognize the lowest level elements of your grammar, like, "here is a dot", or "here is an big endian integer". |
| //! |
| //! | combinator | usage | input | output | comment | |
| //! |---|---|---|---|---| |
| //! | [`one_of`][crate::bytes::one_of] | `one_of("abc")` | `"abc"` | `Ok(("bc", 'a'))` |Matches one of the provided characters (works with non ASCII characters too)| |
| //! | [`none_of`][crate::bytes::none_of] | `none_of("abc")` | `"xyab"` | `Ok(("yab", 'x'))` |Matches anything but the provided characters| |
| //! | [`tag`][crate::bytes::tag] | `"hello"` | `"hello world"` | `Ok((" world", "hello"))` |Recognizes a specific suite of characters or bytes| |
| //! | [`tag_no_case`][crate::bytes::tag_no_case] | `tag_no_case("hello")` | `"HeLLo World"` | `Ok((" World", "HeLLo"))` |Case insensitive comparison. Note that case insensitive comparison is not well defined for unicode, and that you might have bad surprises| |
| //! | [`take`][crate::bytes::take] | `take(4)` | `"hello"` | `Ok(("o", "hell"))` |Takes a specific number of bytes or characters| |
| //! | [`take_while0`][crate::bytes::take_while0] | `take_while0(is_alphabetic)` | `"abc123"` | `Ok(("123", "abc"))` |Returns the longest list of bytes for which the provided pattern matches. `take_while1` does the same, but must return at least one character| |
| //! | [`take_till0`][crate::bytes::take_till0] | `take_till0(is_alphabetic)` | `"123abc"` | `Ok(("abc", "123"))` |Returns the longest list of bytes or characters until the provided pattern matches. `take_till1` does the same, but must return at least one character. This is the reverse behaviour from `take_while0`: `take_till(f)` is equivalent to `take_while0(\|c\| !f(c))`| |
| //! | [`take_until0`][crate::bytes::take_until0] | `take_until0("world")` | `"Hello world"` | `Ok(("world", "Hello "))` |Returns the longest list of bytes or characters until the provided tag is found. `take_until1` does the same, but must return at least one character| |
| //! |
| //! ## Choice combinators |
| //! |
| //! | combinator | usage | input | output | comment | |
| //! |---|---|---|---|---| |
| //! | [`alt`][crate::branch::alt] | `alt(("ab", "cd"))` | `"cdef"` | `Ok(("ef", "cd"))` |Try a list of parsers and return the result of the first successful one| |
| //! | [`dispatch`][crate::branch::dispatch] | \- | \- | \- | `match` for parsers | |
| //! | [`permutation`][crate::branch::permutation] | `permutation(("ab", "cd", "12"))` | `"cd12abc"` | `Ok(("c", ("ab", "cd", "12"))` |Succeeds when all its child parser have succeeded, whatever the order| |
| //! |
| //! ## Sequence combinators |
| //! |
| //! | combinator | usage | input | output | comment | |
| //! |---|---|---|---|---| |
| //! | [`(...)` (tuples)][crate::Parser] | `("ab", "XY", take(1))` | `"abXYZ!"` | `Ok(("!", ("ab", "XY", "Z")))` |Chains parsers and assemble the sub results in a tuple. You can use as many child parsers as you can put elements in a tuple| |
| //! | [`delimited`][crate::sequence::delimited] | `delimited(char('('), take(2), char(')'))` | `"(ab)cd"` | `Ok(("cd", "ab"))` || |
| //! | [`preceded`][crate::sequence::preceded] | `preceded("ab", "XY")` | `"abXYZ"` | `Ok(("Z", "XY"))` || |
| //! | [`terminated`][crate::sequence::terminated] | `terminated("ab", "XY")` | `"abXYZ"` | `Ok(("Z", "ab"))` || |
| //! | [`separated_pair`][crate::sequence::separated_pair] | `separated_pair("hello", char(','), "world")` | `"hello,world!"` | `Ok(("!", ("hello", "world")))` || |
| //! |
| //! ## Applying a parser multiple times |
| //! |
| //! | combinator | usage | input | output | comment | |
| //! |---|---|---|---|---| |
| //! | [`count`][crate::multi::count] | `count(take(2), 3)` | `"abcdefgh"` | `Ok(("gh", vec!["ab", "cd", "ef"]))` |Applies the child parser a specified number of times| |
| //! | [`many0`][crate::multi::many0] | `many0("ab")` | `"abababc"` | `Ok(("c", vec!["ab", "ab", "ab"]))` |Applies the parser 0 or more times and returns the list of results in a Vec. `many1` does the same operation but must return at least one element| |
| //! | [`many_m_n`][crate::multi::many_m_n] | `many_m_n(1, 3, "ab")` | `"ababc"` | `Ok(("c", vec!["ab", "ab"]))` |Applies the parser between m and n times (n included) and returns the list of results in a Vec| |
| //! | [`many_till0`][crate::multi::many_till0] | `many_till0(tag( "ab" ), tag( "ef" ))` | `"ababefg"` | `Ok(("g", (vec!["ab", "ab"], "ef")))` |Applies the first parser until the second applies. Returns a tuple containing the list of results from the first in a Vec and the result of the second| |
| //! | [`separated0`][crate::multi::separated0] | `separated0("ab", ",")` | `"ab,ab,ab."` | `Ok((".", vec!["ab", "ab", "ab"]))` |`separated1` works like `separated0` but must returns at least one element| |
| //! | [`fold_many0`][crate::multi::fold_many0] | `fold_many0(be_u8, \|\| 0, \|acc, item\| acc + item)` | `[1, 2, 3]` | `Ok(([], 6))` |Applies the parser 0 or more times and folds the list of return values. The `fold_many1` version must apply the child parser at least one time| |
| //! | [`fold_many_m_n`][crate::multi::fold_many_m_n] | `fold_many_m_n(1, 2, be_u8, \|\| 0, \|acc, item\| acc + item)` | `[1, 2, 3]` | `Ok(([3], 3))` |Applies the parser between m and n times (n included) and folds the list of return value| |
| //! | [`length_count`][crate::multi::length_count] | `length_count(number, "ab")` | `"2ababab"` | `Ok(("ab", vec!["ab", "ab"]))` |Gets a number from the first parser, then applies the second parser that many times| |
| //! |
| //! ## Partial related |
| //! |
| //! - [`eof`][eof]: Returns its input if it is at the end of input data |
| //! - [`Parser::complete_err`]: Replaces an `Incomplete` returned by the child parser with an `Backtrack` |
| //! |
| //! ## Modifiers |
| //! |
| //! - [`cond`][cond]: Conditional combinator. Wraps another parser and calls it if the condition is met |
| //! - [`Parser::flat_map`][crate::Parser::flat_map]: method to map a new parser from the output of the first parser, then apply that parser over the rest of the input |
| //! - [`Parser::value`][crate::Parser::value]: method to replace the result of a parser |
| //! - [`Parser::map`][crate::Parser::map]: method to map a function on the result of a parser |
| //! - [`Parser::and_then`][crate::Parser::and_then]: Applies a second parser over the output of the first one |
| //! - [`Parser::verify_map`][Parser::verify_map]: Maps a function returning an `Option` on the output of a parser |
| //! - [`Parser::map_res`][Parser::map_res]: Maps a function returning a `Result` on the output of a parser |
| //! - [`Parser::parse_to`][crate::Parser::parse_to]: Apply [`std::str::FromStr`] to the output of the parser |
| //! - [`not`][not]: Returns a result only if the embedded parser returns `Backtrack` or `Incomplete`. Does not consume the input |
| //! - [`opt`][opt]: Make the underlying parser optional |
| //! - [`peek`][peek]: Returns a result without consuming the input |
| //! - [`Parser::recognize`][Parser::recognize]: If the child parser was successful, return the consumed input as the produced value |
| //! - [`Parser::with_recognized`][Parser::with_recognized]: If the child parser was successful, return a tuple of the consumed input and the produced output. |
| //! - [`Parser::span`][Parser::span]: If the child parser was successful, return the location of the consumed input as the produced value |
| //! - [`Parser::with_span`][Parser::with_span]: If the child parser was successful, return a tuple of the location of the consumed input and the produced output. |
| //! - [`Parser::verify`]: Returns the result of the child parser if it satisfies a verification function |
| //! |
| //! ## Error management and debugging |
| //! |
| //! - [`cut_err`]: Commit the parse result, disallowing alternative parsers from being attempted |
| //! - [`backtrack_err`]: Attemmpts a parse, allowing alternative parsers to be attempted despite |
| //! use of `cut_err` |
| //! - [`Parser::context`]: Add context to the error if the parser fails |
| //! - [`trace`][crate::trace::trace]: Print the parse state with the `debug` feature flag |
| //! - [`todo()`]: Placeholder parser |
| //! |
| //! ## Remaining combinators |
| //! |
| //! - [`success`][success]: Returns a value without consuming any input, always succeeds |
| //! - [`fail`][fail]: Inversion of `success`. Always fails. |
| //! - [`Parser::by_ref`]: Allow moving `&mut impl Parser` into other parsers |
| //! |
| //! ## Text parsing |
| //! |
| //! - [`any`][crate::bytes::any]: Matches one token |
| //! - [`tab`][crate::character::tab]: Matches a tab character `\t` |
| //! - [`crlf`][crate::character::crlf]: Recognizes the string `\r\n` |
| //! - [`line_ending`][crate::character::line_ending]: Recognizes an end of line (both `\n` and `\r\n`) |
| //! - [`newline`][crate::character::newline]: Matches a newline character `\n` |
| //! - [`not_line_ending`][crate::character::not_line_ending]: Recognizes a string of any char except `\r` or `\n` |
| //! - [`rest`][rest]: Return the remaining input |
| //! |
| //! - [`alpha0`][crate::character::alpha0]: Recognizes zero or more lowercase and uppercase alphabetic characters: `[a-zA-Z]`. [`alpha1`][crate::character::alpha1] does the same but returns at least one character |
| //! - [`alphanumeric0`][crate::character::alphanumeric0]: Recognizes zero or more numerical and alphabetic characters: `[0-9a-zA-Z]`. [`alphanumeric1`][crate::character::alphanumeric1] does the same but returns at least one character |
| //! - [`space0`][crate::character::space0]: Recognizes zero or more spaces and tabs. [`space1`][crate::character::space1] does the same but returns at least one character |
| //! - [`multispace0`][crate::character::multispace0]: Recognizes zero or more spaces, tabs, carriage returns and line feeds. [`multispace1`][crate::character::multispace1] does the same but returns at least one character |
| //! - [`digit0`][crate::character::digit0]: Recognizes zero or more numerical characters: `[0-9]`. [`digit1`][crate::character::digit1] does the same but returns at least one character |
| //! - [`hex_digit0`][crate::character::hex_digit0]: Recognizes zero or more hexadecimal numerical characters: `[0-9A-Fa-f]`. [`hex_digit1`][crate::character::hex_digit1] does the same but returns at least one character |
| //! - [`oct_digit0`][crate::character::oct_digit0]: Recognizes zero or more octal characters: `[0-7]`. [`oct_digit1`][crate::character::oct_digit1] does the same but returns at least one character |
| //! |
| //! - [`float`][crate::character::float]: Parse a floating point number in a byte string |
| //! - [`dec_int`][crate::character::dec_uint]: Decode a variable-width, decimal signed integer |
| //! - [`dec_uint`][crate::character::dec_uint]: Decode a variable-width, decimal unsigned integer |
| //! - [`hex_uint`][crate::character::hex_uint]: Decode a variable-width, hexadecimal integer |
| //! |
| //! - [`escaped`][crate::character::escaped]: Matches a byte string with escaped characters |
| //! - [`escaped_transform`][crate::character::escaped_transform]: Matches a byte string with escaped characters, and returns a new string with the escaped characters replaced |
| //! |
| //! ### Character test functions |
| //! |
| //! Use these functions with a combinator like `take_while0`: |
| //! |
| //! - [`AsChar::is_alpha`][crate::stream::AsChar::is_alpha]: Tests if byte is ASCII alphabetic: `[A-Za-z]` |
| //! - [`AsChar::is_alphanum`][crate::stream::AsChar::is_alphanum]: Tests if byte is ASCII alphanumeric: `[A-Za-z0-9]` |
| //! - [`AsChar::is_dec_digit`][crate::stream::AsChar::is_dec_digit]: Tests if byte is ASCII digit: `[0-9]` |
| //! - [`AsChar::is_hex_digit`][crate::stream::AsChar::is_hex_digit]: Tests if byte is ASCII hex digit: `[0-9A-Fa-f]` |
| //! - [`AsChar::is_oct_digit`][crate::stream::AsChar::is_oct_digit]: Tests if byte is ASCII octal digit: `[0-7]` |
| //! - [`AsChar::is_space`][crate::stream::AsChar::is_space]: Tests if byte is ASCII space or tab: `[ \t]` |
| //! - [`AsChar::is_newline`][crate::stream::AsChar::is_newline]: Tests if byte is ASCII newline: `[\n]` |
| //! |
| //! ## Binary format parsing |
| //! |
| //! - [`length_data`][crate::multi::length_data]: Gets a number from the first parser, then takes a subslice of the input of that size, and returns that subslice |
| //! - [`length_value`][crate::multi::length_value]: Gets a number from the first parser, takes a subslice of the input of that size, then applies the second parser on that subslice. If the second parser returns `Incomplete`, `length_value` will return an error |
| //! |
| //! ### Integers |
| //! |
| //! Parsing integers from binary formats can be done in two ways: With parser functions, or combinators with configurable endianness. |
| //! |
| //! - **configurable endianness:** [`i16`][crate::number::i16], [`i32`][crate::number::i32], |
| //! [`i64`][crate::number::i64], [`u16`][crate::number::u16], [`u32`][crate::number::u32], |
| //! [`u64`][crate::number::u64] are combinators that take as argument a |
| //! [`winnow::number::Endianness`][crate::number::Endianness], like this: `i16(endianness)`. If the |
| //! parameter is `winnow::number::Endianness::Big`, parse a big endian `i16` integer, otherwise a |
| //! little endian `i16` integer. |
| //! - **fixed endianness**: The functions are prefixed by `be_` for big endian numbers, and by `le_` for little endian numbers, and the suffix is the type they parse to. As an example, `be_u32` parses a big endian unsigned integer stored in 32 bits. |
| //! - [`be_f32`][crate::number::be_f32], [`be_f64`][crate::number::be_f64]: Big endian floating point numbers |
| //! - [`le_f32`][crate::number::le_f32], [`le_f64`][crate::number::le_f64]: Little endian floating point numbers |
| //! - [`be_i8`][crate::number::be_i8], [`be_i16`][crate::number::be_i16], [`be_i24`][crate::number::be_i24], [`be_i32`][crate::number::be_i32], [`be_i64`][crate::number::be_i64], [`be_i128`][crate::number::be_i128]: Big endian signed integers |
| //! - [`be_u8`][crate::number::be_u8], [`be_u16`][crate::number::be_u16], [`be_u24`][crate::number::be_u24], [`be_u32`][crate::number::be_u32], [`be_u64`][crate::number::be_u64], [`be_u128`][crate::number::be_u128]: Big endian unsigned integers |
| //! - [`le_i8`][crate::number::le_i8], [`le_i16`][crate::number::le_i16], [`le_i24`][crate::number::le_i24], [`le_i32`][crate::number::le_i32], [`le_i64`][crate::number::le_i64], [`le_i128`][crate::number::le_i128]: Little endian signed integers |
| //! - [`le_u8`][crate::number::le_u8], [`le_u16`][crate::number::le_u16], [`le_u24`][crate::number::le_u24], [`le_u32`][crate::number::le_u32], [`le_u64`][crate::number::le_u64], [`le_u128`][crate::number::le_u128]: Little endian unsigned integers |
| //! |
| //! ### Bit stream parsing |
| //! |
| //! - [`bits`][crate::bits::bits]: Transforms the current input type (byte slice `&[u8]`) to a bit stream on which bit specific parsers and more general combinators can be applied |
| //! - [`bytes`][crate::bits::bytes]: Transforms its bits stream input back into a byte slice for the underlying parser |
| //! - [`take`][crate::bits::take]: Take a set number of its |
| //! - [`tag`][crate::bits::tag]: Check if a set number of bis matches a pattern |
| //! - [`bool`][crate::bits::bool]: Match any one bit |
| |
| use crate::error::{ContextError, ErrMode, ErrorKind, FromExternalError, Needed, ParseError}; |
| use crate::lib::std::borrow::Borrow; |
| use crate::lib::std::ops::Range; |
| use crate::stream::{Location, Stream}; |
| use crate::stream::{Offset, StreamIsPartial}; |
| use crate::trace::trace; |
| use crate::trace::trace_result; |
| use crate::*; |
| |
| #[cfg(test)] |
| mod tests; |
| |
| /// Return the remaining input. |
| /// |
| /// # Example |
| /// |
| /// ```rust |
| /// # use winnow::error::ErrorKind; |
| /// # use winnow::error::Error; |
| /// use winnow::combinator::rest; |
| /// assert_eq!(rest::<_,Error<_>>("abc"), Ok(("", "abc"))); |
| /// assert_eq!(rest::<_,Error<_>>(""), Ok(("", ""))); |
| /// ``` |
| #[inline] |
| pub fn rest<I, E: ParseError<I>>(input: I) -> IResult<I, <I as Stream>::Slice, E> |
| where |
| I: Stream, |
| { |
| trace("rest", move |input: I| { |
| Ok(input.next_slice(input.eof_offset())) |
| }) |
| .parse_next(input) |
| } |
| |
| /// Return the length of the remaining input. |
| /// |
| /// Note: this does not advance the [`Stream`] |
| /// |
| /// # Example |
| /// |
| /// ```rust |
| /// # use winnow::error::ErrorKind; |
| /// # use winnow::error::Error; |
| /// use winnow::combinator::rest_len; |
| /// assert_eq!(rest_len::<_,Error<_>>("abc"), Ok(("abc", 3))); |
| /// assert_eq!(rest_len::<_,Error<_>>(""), Ok(("", 0))); |
| /// ``` |
| #[inline] |
| pub fn rest_len<I, E: ParseError<I>>(input: I) -> IResult<I, usize, E> |
| where |
| I: Stream, |
| { |
| trace("rest_len", move |input: I| { |
| let len = input.eof_offset(); |
| Ok((input, len)) |
| }) |
| .parse_next(input) |
| } |
| |
| /// Implementation of [`Parser::by_ref`][Parser::by_ref] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct ByRef<'p, P> { |
| p: &'p mut P, |
| } |
| |
| impl<'p, P> ByRef<'p, P> { |
| pub(crate) fn new(p: &'p mut P) -> Self { |
| Self { p } |
| } |
| } |
| |
| impl<'p, I, O, E, P: Parser<I, O, E>> Parser<I, O, E> for ByRef<'p, P> { |
| fn parse_next(&mut self, i: I) -> IResult<I, O, E> { |
| self.p.parse_next(i) |
| } |
| } |
| |
| /// Implementation of [`Parser::map`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct Map<F, G, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: Fn(O) -> O2, |
| { |
| parser: F, |
| map: G, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| o2: core::marker::PhantomData<O2>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, G, I, O, O2, E> Map<F, G, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: Fn(O) -> O2, |
| { |
| pub(crate) fn new(parser: F, map: G) -> Self { |
| Self { |
| parser, |
| map, |
| i: Default::default(), |
| o: Default::default(), |
| o2: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, G, I, O, O2, E> Parser<I, O2, E> for Map<F, G, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: Fn(O) -> O2, |
| { |
| fn parse_next(&mut self, i: I) -> IResult<I, O2, E> { |
| match self.parser.parse_next(i) { |
| Err(e) => Err(e), |
| Ok((i, o)) => Ok((i, (self.map)(o))), |
| } |
| } |
| } |
| |
| /// Implementation of [`Parser::map_res`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct MapRes<F, G, I, O, O2, E, E2> |
| where |
| F: Parser<I, O, E>, |
| G: FnMut(O) -> Result<O2, E2>, |
| I: Clone, |
| E: FromExternalError<I, E2>, |
| { |
| parser: F, |
| map: G, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| o2: core::marker::PhantomData<O2>, |
| e: core::marker::PhantomData<E>, |
| e2: core::marker::PhantomData<E2>, |
| } |
| |
| impl<F, G, I, O, O2, E, E2> MapRes<F, G, I, O, O2, E, E2> |
| where |
| F: Parser<I, O, E>, |
| G: FnMut(O) -> Result<O2, E2>, |
| I: Clone, |
| E: FromExternalError<I, E2>, |
| { |
| pub(crate) fn new(parser: F, map: G) -> Self { |
| Self { |
| parser, |
| map, |
| i: Default::default(), |
| o: Default::default(), |
| o2: Default::default(), |
| e: Default::default(), |
| e2: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, G, I, O, O2, E, E2> Parser<I, O2, E> for MapRes<F, G, I, O, O2, E, E2> |
| where |
| F: Parser<I, O, E>, |
| G: FnMut(O) -> Result<O2, E2>, |
| I: Clone, |
| E: FromExternalError<I, E2>, |
| { |
| fn parse_next(&mut self, input: I) -> IResult<I, O2, E> { |
| let i = input.clone(); |
| let (input, o) = self.parser.parse_next(input)?; |
| let res = match (self.map)(o) { |
| Ok(o2) => Ok((input, o2)), |
| Err(e) => Err(ErrMode::from_external_error(i, ErrorKind::Verify, e)), |
| }; |
| trace_result("verify", &res); |
| res |
| } |
| } |
| |
| /// Implementation of [`Parser::verify_map`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct VerifyMap<F, G, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: FnMut(O) -> Option<O2>, |
| I: Clone, |
| E: ParseError<I>, |
| { |
| parser: F, |
| map: G, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| o2: core::marker::PhantomData<O2>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, G, I, O, O2, E> VerifyMap<F, G, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: FnMut(O) -> Option<O2>, |
| I: Clone, |
| E: ParseError<I>, |
| { |
| pub(crate) fn new(parser: F, map: G) -> Self { |
| Self { |
| parser, |
| map, |
| i: Default::default(), |
| o: Default::default(), |
| o2: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, G, I, O, O2, E> Parser<I, O2, E> for VerifyMap<F, G, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: FnMut(O) -> Option<O2>, |
| I: Clone, |
| E: ParseError<I>, |
| { |
| fn parse_next(&mut self, input: I) -> IResult<I, O2, E> { |
| let i = input.clone(); |
| let (input, o) = self.parser.parse_next(input)?; |
| let res = match (self.map)(o) { |
| Some(o2) => Ok((input, o2)), |
| None => Err(ErrMode::from_error_kind(i, ErrorKind::Verify)), |
| }; |
| trace_result("verify", &res); |
| res |
| } |
| } |
| |
| /// Implementation of [`Parser::and_then`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct AndThen<F, G, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: Parser<O, O2, E>, |
| O: StreamIsPartial, |
| { |
| outer: F, |
| inner: G, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| o2: core::marker::PhantomData<O2>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, G, I, O, O2, E> AndThen<F, G, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: Parser<O, O2, E>, |
| O: StreamIsPartial, |
| { |
| pub(crate) fn new(outer: F, inner: G) -> Self { |
| Self { |
| outer, |
| inner, |
| i: Default::default(), |
| o: Default::default(), |
| o2: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, G, I, O, O2, E> Parser<I, O2, E> for AndThen<F, G, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: Parser<O, O2, E>, |
| O: StreamIsPartial, |
| { |
| fn parse_next(&mut self, i: I) -> IResult<I, O2, E> { |
| let (i, mut o) = self.outer.parse_next(i)?; |
| let _ = o.complete(); |
| let (_, o2) = self.inner.parse_next(o)?; |
| Ok((i, o2)) |
| } |
| } |
| |
| /// Implementation of [`Parser::parse_to`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct ParseTo<P, I, O, O2, E> |
| where |
| P: Parser<I, O, E>, |
| I: Stream, |
| O: crate::stream::ParseSlice<O2>, |
| E: ParseError<I>, |
| { |
| p: P, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| o2: core::marker::PhantomData<O2>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<P, I, O, O2, E> ParseTo<P, I, O, O2, E> |
| where |
| P: Parser<I, O, E>, |
| I: Stream, |
| O: crate::stream::ParseSlice<O2>, |
| E: ParseError<I>, |
| { |
| pub(crate) fn new(p: P) -> Self { |
| Self { |
| p, |
| i: Default::default(), |
| o: Default::default(), |
| o2: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<P, I, O, O2, E> Parser<I, O2, E> for ParseTo<P, I, O, O2, E> |
| where |
| P: Parser<I, O, E>, |
| I: Stream, |
| O: crate::stream::ParseSlice<O2>, |
| E: ParseError<I>, |
| { |
| fn parse_next(&mut self, i: I) -> IResult<I, O2, E> { |
| let input = i.clone(); |
| let (i, o) = self.p.parse_next(i)?; |
| |
| let res = o |
| .parse_slice() |
| .ok_or_else(|| ErrMode::from_error_kind(input, ErrorKind::Verify)); |
| trace_result("verify", &res); |
| Ok((i, res?)) |
| } |
| } |
| |
| /// Implementation of [`Parser::flat_map`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct FlatMap<F, G, H, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: FnMut(O) -> H, |
| H: Parser<I, O2, E>, |
| { |
| f: F, |
| g: G, |
| h: core::marker::PhantomData<H>, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| o2: core::marker::PhantomData<O2>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, G, H, I, O, O2, E> FlatMap<F, G, H, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: FnMut(O) -> H, |
| H: Parser<I, O2, E>, |
| { |
| pub(crate) fn new(f: F, g: G) -> Self { |
| Self { |
| f, |
| g, |
| h: Default::default(), |
| i: Default::default(), |
| o: Default::default(), |
| o2: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, G, H, I, O, O2, E> Parser<I, O2, E> for FlatMap<F, G, H, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: FnMut(O) -> H, |
| H: Parser<I, O2, E>, |
| { |
| fn parse_next(&mut self, i: I) -> IResult<I, O2, E> { |
| let (i, o) = self.f.parse_next(i)?; |
| (self.g)(o).parse_next(i) |
| } |
| } |
| |
| /// Apply a [`Parser`], producing `None` on [`ErrMode::Backtrack`]. |
| /// |
| /// To chain an error up, see [`cut_err`]. |
| /// |
| /// # Example |
| /// |
| /// ```rust |
| /// # use winnow::{error::ErrMode, error::ErrorKind, error::Error}; |
| /// # use winnow::prelude::*; |
| /// use winnow::combinator::opt; |
| /// use winnow::character::alpha1; |
| /// # fn main() { |
| /// |
| /// fn parser(i: &str) -> IResult<&str, Option<&str>> { |
| /// opt(alpha1).parse_next(i) |
| /// } |
| /// |
| /// assert_eq!(parser("abcd;"), Ok((";", Some("abcd")))); |
| /// assert_eq!(parser("123;"), Ok(("123;", None))); |
| /// # } |
| /// ``` |
| pub fn opt<I: Stream, O, E: ParseError<I>, F>(mut f: F) -> impl Parser<I, Option<O>, E> |
| where |
| F: Parser<I, O, E>, |
| { |
| trace("opt", move |input: I| { |
| let i = input.clone(); |
| match f.parse_next(input) { |
| Ok((i, o)) => Ok((i, Some(o))), |
| Err(ErrMode::Backtrack(_)) => Ok((i, None)), |
| Err(e) => Err(e), |
| } |
| }) |
| } |
| |
| /// Calls the parser if the condition is met. |
| /// |
| /// # Example |
| /// |
| /// ```rust |
| /// # use winnow::{error::ErrMode, error::{Error, ErrorKind}, IResult}; |
| /// # use winnow::prelude::*; |
| /// use winnow::combinator::cond; |
| /// use winnow::character::alpha1; |
| /// # fn main() { |
| /// |
| /// fn parser(b: bool, i: &str) -> IResult<&str, Option<&str>> { |
| /// cond(b, alpha1).parse_next(i) |
| /// } |
| /// |
| /// assert_eq!(parser(true, "abcd;"), Ok((";", Some("abcd")))); |
| /// assert_eq!(parser(false, "abcd;"), Ok(("abcd;", None))); |
| /// assert_eq!(parser(true, "123;"), Err(ErrMode::Backtrack(Error::new("123;", ErrorKind::Slice)))); |
| /// assert_eq!(parser(false, "123;"), Ok(("123;", None))); |
| /// # } |
| /// ``` |
| pub fn cond<I, O, E: ParseError<I>, F>(b: bool, mut f: F) -> impl Parser<I, Option<O>, E> |
| where |
| I: Stream, |
| F: Parser<I, O, E>, |
| { |
| trace("cond", move |input: I| { |
| if b { |
| match f.parse_next(input) { |
| Ok((i, o)) => Ok((i, Some(o))), |
| Err(e) => Err(e), |
| } |
| } else { |
| Ok((input, None)) |
| } |
| }) |
| } |
| |
| /// Tries to apply its parser without consuming the input. |
| /// |
| /// # Example |
| /// |
| /// ```rust |
| /// # use winnow::{error::ErrMode, error::ErrorKind, error::Error, IResult}; |
| /// # use winnow::prelude::*; |
| /// use winnow::combinator::peek; |
| /// use winnow::character::alpha1; |
| /// # fn main() { |
| /// |
| /// let mut parser = peek(alpha1); |
| /// |
| /// assert_eq!(parser.parse_next("abcd;"), Ok(("abcd;", "abcd"))); |
| /// assert_eq!(parser.parse_next("123;"), Err(ErrMode::Backtrack(Error::new("123;", ErrorKind::Slice)))); |
| /// # } |
| /// ``` |
| #[doc(alias = "look_ahead")] |
| #[doc(alias = "rewind")] |
| pub fn peek<I: Stream, O, E: ParseError<I>, F>(mut f: F) -> impl Parser<I, O, E> |
| where |
| F: Parser<I, O, E>, |
| { |
| trace("peek", move |input: I| { |
| let i = input.clone(); |
| match f.parse_next(input) { |
| Ok((_, o)) => Ok((i, o)), |
| Err(e) => Err(e), |
| } |
| }) |
| } |
| |
| /// Match the end of the [`Stream`] |
| /// |
| /// Otherwise, it will error. |
| /// |
| /// # Example |
| /// |
| /// ```rust |
| /// # use std::str; |
| /// # use winnow::{error::ErrMode, error::ErrorKind, error::Error}; |
| /// # use winnow::combinator::eof; |
| /// # use winnow::prelude::*; |
| /// |
| /// let mut parser = eof; |
| /// assert_eq!(parser.parse_next("abc"), Err(ErrMode::Backtrack(Error::new("abc", ErrorKind::Eof)))); |
| /// assert_eq!(parser.parse_next(""), Ok(("", ""))); |
| /// ``` |
| #[doc(alias = "end")] |
| #[doc(alias = "eoi")] |
| pub fn eof<I, E: ParseError<I>>(input: I) -> IResult<I, <I as Stream>::Slice, E> |
| where |
| I: Stream, |
| { |
| trace("eof", move |input: I| { |
| if input.eof_offset() == 0 { |
| Ok(input.next_slice(0)) |
| } else { |
| Err(ErrMode::from_error_kind(input, ErrorKind::Eof)) |
| } |
| }) |
| .parse_next(input) |
| } |
| |
| /// Implementation of [`Parser::complete_err`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct CompleteErr<F> { |
| f: F, |
| } |
| |
| impl<F> CompleteErr<F> { |
| pub(crate) fn new(f: F) -> Self { |
| Self { f } |
| } |
| } |
| |
| impl<F, I, O, E> Parser<I, O, E> for CompleteErr<F> |
| where |
| I: Stream, |
| F: Parser<I, O, E>, |
| E: ParseError<I>, |
| { |
| fn parse_next(&mut self, input: I) -> IResult<I, O, E> { |
| trace("complete_err", |input: I| { |
| let i = input.clone(); |
| match (self.f).parse_next(input) { |
| Err(ErrMode::Incomplete(_)) => { |
| Err(ErrMode::from_error_kind(i, ErrorKind::Complete)) |
| } |
| rest => rest, |
| } |
| }) |
| .parse_next(input) |
| } |
| } |
| |
| /// Implementation of [`Parser::verify`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct Verify<F, G, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: Fn(&O2) -> bool, |
| I: Clone, |
| O: Borrow<O2>, |
| O2: ?Sized, |
| E: ParseError<I>, |
| { |
| parser: F, |
| filter: G, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| o2: core::marker::PhantomData<O2>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, G, I, O, O2, E> Verify<F, G, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: Fn(&O2) -> bool, |
| I: Clone, |
| O: Borrow<O2>, |
| O2: ?Sized, |
| E: ParseError<I>, |
| { |
| pub(crate) fn new(parser: F, filter: G) -> Self { |
| Self { |
| parser, |
| filter, |
| i: Default::default(), |
| o: Default::default(), |
| o2: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, G, I, O, O2, E> Parser<I, O, E> for Verify<F, G, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| G: Fn(&O2) -> bool, |
| I: Clone, |
| O: Borrow<O2>, |
| O2: ?Sized, |
| E: ParseError<I>, |
| { |
| fn parse_next(&mut self, input: I) -> IResult<I, O, E> { |
| let i = input.clone(); |
| let (input, o) = self.parser.parse_next(input)?; |
| |
| let res = if (self.filter)(o.borrow()) { |
| Ok((input, o)) |
| } else { |
| Err(ErrMode::from_error_kind(i, ErrorKind::Verify)) |
| }; |
| trace_result("verify", &res); |
| res |
| } |
| } |
| |
| /// Implementation of [`Parser::value`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct Value<F, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| O2: Clone, |
| { |
| parser: F, |
| val: O2, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, I, O, O2, E> Value<F, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| O2: Clone, |
| { |
| pub(crate) fn new(parser: F, val: O2) -> Self { |
| Self { |
| parser, |
| val, |
| i: Default::default(), |
| o: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, I, O, O2, E> Parser<I, O2, E> for Value<F, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| O2: Clone, |
| { |
| fn parse_next(&mut self, input: I) -> IResult<I, O2, E> { |
| (self.parser) |
| .parse_next(input) |
| .map(|(i, _)| (i, self.val.clone())) |
| } |
| } |
| |
| /// Implementation of [`Parser::void`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct Void<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| { |
| parser: F, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, I, O, E> Void<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| { |
| pub(crate) fn new(parser: F) -> Self { |
| Self { |
| parser, |
| i: Default::default(), |
| o: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, I, O, E> Parser<I, (), E> for Void<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| { |
| fn parse_next(&mut self, input: I) -> IResult<I, (), E> { |
| (self.parser).parse_next(input).map(|(i, _)| (i, ())) |
| } |
| } |
| |
| /// Succeeds if the child parser returns an error. |
| /// |
| /// **Note:** This does not advance the [`Stream`] |
| /// |
| /// # Example |
| /// |
| /// ```rust |
| /// # use winnow::{error::ErrMode, error::ErrorKind, error::Error, IResult}; |
| /// # use winnow::prelude::*; |
| /// use winnow::combinator::not; |
| /// use winnow::character::alpha1; |
| /// # fn main() { |
| /// |
| /// let mut parser = not(alpha1); |
| /// |
| /// assert_eq!(parser.parse_next("123"), Ok(("123", ()))); |
| /// assert_eq!(parser.parse_next("abcd"), Err(ErrMode::Backtrack(Error::new("abcd", ErrorKind::Not)))); |
| /// # } |
| /// ``` |
| pub fn not<I: Stream, O, E: ParseError<I>, F>(mut parser: F) -> impl Parser<I, (), E> |
| where |
| F: Parser<I, O, E>, |
| { |
| trace("not", move |input: I| { |
| let i = input.clone(); |
| match parser.parse_next(input) { |
| Ok(_) => Err(ErrMode::from_error_kind(i, ErrorKind::Not)), |
| Err(ErrMode::Backtrack(_)) => Ok((i, ())), |
| Err(e) => Err(e), |
| } |
| }) |
| } |
| |
| /// Implementation of [`Parser::recognize`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct Recognize<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Stream + Offset, |
| { |
| parser: F, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, I, O, E> Recognize<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Stream + Offset, |
| { |
| pub(crate) fn new(parser: F) -> Self { |
| Self { |
| parser, |
| i: Default::default(), |
| o: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<I, O, E, F> Parser<I, <I as Stream>::Slice, E> for Recognize<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Stream + Offset, |
| { |
| fn parse_next(&mut self, input: I) -> IResult<I, <I as Stream>::Slice, E> { |
| let i = input.clone(); |
| match (self.parser).parse_next(i) { |
| Ok((i, _)) => { |
| let offset = input.offset_to(&i); |
| Ok(input.next_slice(offset)) |
| } |
| Err(e) => Err(e), |
| } |
| } |
| } |
| |
| /// Implementation of [`Parser::with_recognized`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct WithRecognized<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Stream + Offset, |
| { |
| parser: F, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, I, O, E> WithRecognized<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Stream + Offset, |
| { |
| pub(crate) fn new(parser: F) -> Self { |
| Self { |
| parser, |
| i: Default::default(), |
| o: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, I, O, E> Parser<I, (O, <I as Stream>::Slice), E> for WithRecognized<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Stream + Offset, |
| { |
| fn parse_next(&mut self, input: I) -> IResult<I, (O, <I as Stream>::Slice), E> { |
| let i = input.clone(); |
| match (self.parser).parse_next(i) { |
| Ok((remaining, result)) => { |
| let offset = input.offset_to(&remaining); |
| let (remaining, recognized) = input.next_slice(offset); |
| Ok((remaining, (result, recognized))) |
| } |
| Err(e) => Err(e), |
| } |
| } |
| } |
| |
| /// Implementation of [`Parser::span`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct Span<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Clone + Location, |
| { |
| parser: F, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, I, O, E> Span<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Clone + Location, |
| { |
| pub(crate) fn new(parser: F) -> Self { |
| Self { |
| parser, |
| i: Default::default(), |
| o: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<I, O, E, F> Parser<I, Range<usize>, E> for Span<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Clone + Location, |
| { |
| fn parse_next(&mut self, input: I) -> IResult<I, Range<usize>, E> { |
| let start = input.location(); |
| self.parser.parse_next(input).map(move |(remaining, _)| { |
| let end = remaining.location(); |
| (remaining, (start..end)) |
| }) |
| } |
| } |
| |
| /// Implementation of [`Parser::with_span`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct WithSpan<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Clone + Location, |
| { |
| parser: F, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, I, O, E> WithSpan<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Clone + Location, |
| { |
| pub(crate) fn new(parser: F) -> Self { |
| Self { |
| parser, |
| i: Default::default(), |
| o: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, I, O, E> Parser<I, (O, Range<usize>), E> for WithSpan<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Clone + Location, |
| { |
| fn parse_next(&mut self, input: I) -> IResult<I, (O, Range<usize>), E> { |
| let start = input.location(); |
| self.parser |
| .parse_next(input) |
| .map(move |(remaining, output)| { |
| let end = remaining.location(); |
| (remaining, (output, (start..end))) |
| }) |
| } |
| } |
| |
| /// Transforms an [`ErrMode::Backtrack`] (recoverable) to [`ErrMode::Cut`] (unrecoverable) |
| /// |
| /// This commits the parse result, preventing alternative branch paths like with |
| /// [`winnow::branch::alt`][crate::branch::alt]. |
| /// |
| /// # Example |
| /// |
| /// Without `cut_err`: |
| /// ```rust |
| /// # use winnow::{error::ErrMode, error::ErrorKind, error::Error}; |
| /// # use winnow::bytes::one_of; |
| /// # use winnow::character::digit1; |
| /// # use winnow::combinator::rest; |
| /// # use winnow::branch::alt; |
| /// # use winnow::sequence::preceded; |
| /// # use winnow::prelude::*; |
| /// # fn main() { |
| /// |
| /// fn parser(input: &str) -> IResult<&str, &str> { |
| /// alt(( |
| /// preceded(one_of("+-"), digit1), |
| /// rest |
| /// )).parse_next(input) |
| /// } |
| /// |
| /// assert_eq!(parser("+10 ab"), Ok((" ab", "10"))); |
| /// assert_eq!(parser("ab"), Ok(("", "ab"))); |
| /// assert_eq!(parser("+"), Ok(("", "+"))); |
| /// # } |
| /// ``` |
| /// |
| /// With `cut_err`: |
| /// ```rust |
| /// # use winnow::{error::ErrMode, error::ErrorKind, error::Error}; |
| /// # use winnow::prelude::*; |
| /// # use winnow::bytes::one_of; |
| /// # use winnow::character::digit1; |
| /// # use winnow::combinator::rest; |
| /// # use winnow::branch::alt; |
| /// # use winnow::sequence::preceded; |
| /// use winnow::combinator::cut_err; |
| /// # fn main() { |
| /// |
| /// fn parser(input: &str) -> IResult<&str, &str> { |
| /// alt(( |
| /// preceded(one_of("+-"), cut_err(digit1)), |
| /// rest |
| /// )).parse_next(input) |
| /// } |
| /// |
| /// assert_eq!(parser("+10 ab"), Ok((" ab", "10"))); |
| /// assert_eq!(parser("ab"), Ok(("", "ab"))); |
| /// assert_eq!(parser("+"), Err(ErrMode::Cut(Error { input: "", kind: ErrorKind::Slice }))); |
| /// # } |
| /// ``` |
| pub fn cut_err<I, O, E: ParseError<I>, F>(mut parser: F) -> impl Parser<I, O, E> |
| where |
| I: Stream, |
| F: Parser<I, O, E>, |
| { |
| trace("cut_err", move |input: I| { |
| parser.parse_next(input).map_err(|e| e.cut()) |
| }) |
| } |
| |
| /// Transforms an [`ErrMode::Cut`] (unrecoverable) to [`ErrMode::Backtrack`] (recoverable) |
| /// |
| /// This attempts the parse, allowing other parsers to be tried on failure, like with |
| /// [`winnow::branch::alt`][crate::branch::alt]. |
| pub fn backtrack_err<I, O, E: ParseError<I>, F>(mut parser: F) -> impl Parser<I, O, E> |
| where |
| I: Stream, |
| F: Parser<I, O, E>, |
| { |
| trace("backtrack_err", move |input: I| { |
| parser.parse_next(input).map_err(|e| e.backtrack()) |
| }) |
| } |
| |
| /// A placeholder for a not-yet-implemented [`Parser`] |
| /// |
| /// This is analogous to the [`todo!`] macro and helps with prototyping. |
| /// |
| /// # Panic |
| /// |
| /// This will panic when parsing |
| /// |
| /// # Example |
| /// |
| /// ```rust |
| /// # use winnow::prelude::*; |
| /// # use winnow::combinator::todo; |
| /// |
| /// fn parser(input: &str) -> IResult<&str, u64> { |
| /// todo(input) |
| /// } |
| /// ``` |
| #[track_caller] |
| pub fn todo<I, O, E>(input: I) -> IResult<I, O, E> |
| where |
| I: Stream, |
| { |
| #![allow(clippy::todo)] |
| trace("todo", move |_input: I| todo!("unimplemented parse")).parse_next(input) |
| } |
| |
| /// Implementation of [`Parser::output_into`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct OutputInto<F, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| O: Into<O2>, |
| { |
| parser: F, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| o2: core::marker::PhantomData<O2>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, I, O, O2, E> OutputInto<F, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| O: Into<O2>, |
| { |
| pub(crate) fn new(parser: F) -> Self { |
| Self { |
| parser, |
| i: Default::default(), |
| o: Default::default(), |
| o2: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, I, O, O2, E> Parser<I, O2, E> for OutputInto<F, I, O, O2, E> |
| where |
| F: Parser<I, O, E>, |
| O: Into<O2>, |
| { |
| fn parse_next(&mut self, i: I) -> IResult<I, O2, E> { |
| match self.parser.parse_next(i) { |
| Ok((i, o)) => Ok((i, o.into())), |
| Err(err) => Err(err), |
| } |
| } |
| } |
| |
| /// Implementation of [`Parser::err_into`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct ErrInto<F, I, O, E, E2> |
| where |
| F: Parser<I, O, E>, |
| E: Into<E2>, |
| { |
| parser: F, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| e: core::marker::PhantomData<E>, |
| e2: core::marker::PhantomData<E2>, |
| } |
| |
| impl<F, I, O, E, E2> ErrInto<F, I, O, E, E2> |
| where |
| F: Parser<I, O, E>, |
| E: Into<E2>, |
| { |
| pub(crate) fn new(parser: F) -> Self { |
| Self { |
| parser, |
| i: Default::default(), |
| o: Default::default(), |
| e: Default::default(), |
| e2: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, I, O, E, E2> Parser<I, O, E2> for ErrInto<F, I, O, E, E2> |
| where |
| F: Parser<I, O, E>, |
| E: Into<E2>, |
| { |
| fn parse_next(&mut self, i: I) -> IResult<I, O, E2> { |
| match self.parser.parse_next(i) { |
| Ok(ok) => Ok(ok), |
| Err(ErrMode::Backtrack(e)) => Err(ErrMode::Backtrack(e.into())), |
| Err(ErrMode::Cut(e)) => Err(ErrMode::Cut(e.into())), |
| Err(ErrMode::Incomplete(e)) => Err(ErrMode::Incomplete(e)), |
| } |
| } |
| } |
| |
| /// Creates an iterator from input data and a parser. |
| /// |
| /// Call the iterator's [`ParserIterator::finish`] method to get the remaining input if successful, |
| /// or the error value if we encountered an error. |
| /// |
| /// On [`ErrMode::Backtrack`], iteration will stop. To instead chain an error up, see [`cut_err`]. |
| /// |
| /// # Example |
| /// |
| /// ```rust |
| /// use winnow::{combinator::iterator, IResult, bytes::tag, character::alpha1, sequence::terminated}; |
| /// use std::collections::HashMap; |
| /// |
| /// let data = "abc|defg|hijkl|mnopqr|123"; |
| /// let mut it = iterator(data, terminated(alpha1, "|")); |
| /// |
| /// let parsed = it.map(|v| (v, v.len())).collect::<HashMap<_,_>>(); |
| /// let res: IResult<_,_> = it.finish(); |
| /// |
| /// assert_eq!(parsed, [("abc", 3usize), ("defg", 4), ("hijkl", 5), ("mnopqr", 6)].iter().cloned().collect()); |
| /// assert_eq!(res, Ok(("123", ()))); |
| /// ``` |
| pub fn iterator<I, O, E, F>(input: I, parser: F) -> ParserIterator<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Stream, |
| E: ParseError<I>, |
| { |
| ParserIterator { |
| parser, |
| input, |
| state: Some(State::Running), |
| o: Default::default(), |
| } |
| } |
| |
| /// Main structure associated to [`iterator`]. |
| pub struct ParserIterator<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Stream, |
| { |
| parser: F, |
| input: I, |
| state: Option<State<E>>, |
| o: core::marker::PhantomData<O>, |
| } |
| |
| impl<F, I, O, E> ParserIterator<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Stream, |
| { |
| /// Returns the remaining input if parsing was successful, or the error if we encountered an error. |
| pub fn finish(mut self) -> IResult<I, (), E> { |
| match self.state.take().unwrap() { |
| State::Running | State::Done => Ok((self.input, ())), |
| State::Failure(e) => Err(ErrMode::Cut(e)), |
| State::Incomplete(i) => Err(ErrMode::Incomplete(i)), |
| } |
| } |
| } |
| |
| impl<'a, F, I, O, E> core::iter::Iterator for &'a mut ParserIterator<F, I, O, E> |
| where |
| F: Parser<I, O, E>, |
| I: Stream, |
| { |
| type Item = O; |
| |
| fn next(&mut self) -> Option<Self::Item> { |
| if let State::Running = self.state.take().unwrap() { |
| let input = self.input.clone(); |
| |
| match self.parser.parse_next(input) { |
| Ok((i, o)) => { |
| self.input = i; |
| self.state = Some(State::Running); |
| Some(o) |
| } |
| Err(ErrMode::Backtrack(_)) => { |
| self.state = Some(State::Done); |
| None |
| } |
| Err(ErrMode::Cut(e)) => { |
| self.state = Some(State::Failure(e)); |
| None |
| } |
| Err(ErrMode::Incomplete(i)) => { |
| self.state = Some(State::Incomplete(i)); |
| None |
| } |
| } |
| } else { |
| None |
| } |
| } |
| } |
| |
| enum State<E> { |
| Running, |
| Done, |
| Failure(E), |
| Incomplete(Needed), |
| } |
| |
| /// Always succeeds with given value without consuming any input. |
| /// |
| /// For example, it can be used as the last alternative in `alt` to |
| /// specify the default case. |
| /// |
| /// **Note:** This never advances the [`Stream`] |
| /// |
| /// # Example |
| /// |
| /// ```rust |
| /// # use winnow::{error::ErrMode, error::ErrorKind, error::Error}; |
| /// # use winnow::prelude::*; |
| /// use winnow::branch::alt; |
| /// use winnow::combinator::success; |
| /// |
| /// let mut parser = success::<_,_,Error<_>>(10); |
| /// assert_eq!(parser.parse_next("xyz"), Ok(("xyz", 10))); |
| /// |
| /// fn sign(input: &str) -> IResult<&str, isize> { |
| /// alt(( |
| /// '-'.value(-1), |
| /// '+'.value(1), |
| /// success::<_,_,Error<_>>(1) |
| /// )).parse_next(input) |
| /// } |
| /// assert_eq!(sign("+10"), Ok(("10", 1))); |
| /// assert_eq!(sign("-10"), Ok(("10", -1))); |
| /// assert_eq!(sign("10"), Ok(("10", 1))); |
| /// ``` |
| #[doc(alias = "value")] |
| #[doc(alias = "empty")] |
| pub fn success<I: Stream, O: Clone, E: ParseError<I>>(val: O) -> impl Parser<I, O, E> { |
| trace("success", move |input: I| Ok((input, val.clone()))) |
| } |
| |
| /// A parser which always fails. |
| /// |
| /// For example, it can be used as the last alternative in `alt` to |
| /// control the error message given. |
| /// |
| /// # Example |
| /// |
| /// ```rust |
| /// # use winnow::{error::ErrMode, error::ErrorKind, error::Error, IResult}; |
| /// use winnow::combinator::fail; |
| /// |
| /// let s = "string"; |
| /// assert_eq!(fail::<_, &str, _>(s), Err(ErrMode::Backtrack(Error::new(s, ErrorKind::Fail)))); |
| /// ``` |
| #[doc(alias = "unexpected")] |
| pub fn fail<I: Stream, O, E: ParseError<I>>(i: I) -> IResult<I, O, E> { |
| trace("fail", |i| { |
| Err(ErrMode::from_error_kind(i, ErrorKind::Fail)) |
| }) |
| .parse_next(i) |
| } |
| |
| /// Implementation of [`Parser::context`] |
| #[cfg_attr(nightly, warn(rustdoc::missing_doc_code_examples))] |
| pub struct Context<F, I, O, E, C> |
| where |
| F: Parser<I, O, E>, |
| I: Stream, |
| E: ContextError<I, C>, |
| C: Clone + crate::lib::std::fmt::Debug, |
| { |
| parser: F, |
| context: C, |
| i: core::marker::PhantomData<I>, |
| o: core::marker::PhantomData<O>, |
| e: core::marker::PhantomData<E>, |
| } |
| |
| impl<F, I, O, E, C> Context<F, I, O, E, C> |
| where |
| F: Parser<I, O, E>, |
| I: Stream, |
| E: ContextError<I, C>, |
| C: Clone + crate::lib::std::fmt::Debug, |
| { |
| pub(crate) fn new(parser: F, context: C) -> Self { |
| Self { |
| parser, |
| context, |
| i: Default::default(), |
| o: Default::default(), |
| e: Default::default(), |
| } |
| } |
| } |
| |
| impl<F, I, O, E, C> Parser<I, O, E> for Context<F, I, O, E, C> |
| where |
| F: Parser<I, O, E>, |
| I: Stream, |
| E: ContextError<I, C>, |
| C: Clone + crate::lib::std::fmt::Debug, |
| { |
| fn parse_next(&mut self, i: I) -> IResult<I, O, E> { |
| #[cfg(feature = "debug")] |
| let name = format!("context={:?}", self.context); |
| #[cfg(not(feature = "debug"))] |
| let name = "context"; |
| trace(name, move |i: I| { |
| (self.parser) |
| .parse_next(i.clone()) |
| .map_err(|err| err.map(|err| err.add_context(i, self.context.clone()))) |
| }) |
| .parse_next(i) |
| } |
| } |