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#![warn( future_incompatible, rust_2018_idioms, missing_docs, missing_doc_code_examples, missing_debug_implementations )] //! # A performant, low-level, lightweight and intuitive combinatoric parser library. //! //! Manger allows for translation of the intuition developed for _Rust_'s primitive and standard //! library types into your intuition for using this library. Most of the behaviour is defined with //! the [`Consumable`] trait, which can be easily implemented using the [`consume_struct`] and //! [`consume_enum`] macros. //! //! This library is suited for deterministic regular languages. It is optimally used in addition to //! a predefined syntax. For example, if you have a predefined //! [EBNF](https://en.wikipedia.org/wiki/Extended_Backus–Naur_form), it is really easy to //! implement the syntax within this crate. //! //! # Getting Started //! //! To get started with implementing [`Consumable`] on your own traits, I suggest taking a look at //! the [`consume_struct`] or [`consume_enum`] documentation. Then you can come back here and look //! at some common patterns. //! //! ## Common patterns //! //! Parsing and thus consuming has a lot of often used patterns. Ofcourse, these are very easily //! available here aswell. //! //! ### Concatenation //! //! Often we want to express that two patterns follow eachother in a `source` string. For example, //! you might want to express that every `Line` is followed by a `';'`. In manger there are two //! ways to do this. //! //! #### Macro's //! //! The first way, and the preferred way, is with the [`consume_struct`] or [`consume_enum`] macros //! where you can present sequential consume instructions. You can see in the following example that //! we are first consuming a `'('`, followed by a [`i32`], followed by a closing `')'`. //! //! ``` //! use manger::{ Consumable, consume_struct }; //! //! struct EncasedInteger(i32); //! consume_struct!( //! EncasedInteger => [ //! > '(', //! value: i32, //! > ')'; //! (value) //! ] //! ); //! ``` //! //! #### Tuples //! //! Another way to represent the same concept is with the tuple type syntax. This can be done with //! up to 10 types. Here we are again parsing the same `(i32)` structure. //! //! ``` //! use manger::chars; //! //! type EncasedInteger = (chars::OpenParenthese, i32, chars::CloseParenthese); //! ``` //! //! ### Repetition //! //! Most of the time you want to represent some kind of repetition. There are a lot of different //! way to represent repetition. Here there are two easy ways. //! //! #### Vec //! //! The easiest way to do repetition is with the [`Vec<T>`][std::vec::Vec]. This will consume 0 or //! more instances of type `T`. Ofcourse, the type `T` has have has [`Consumable`] implemented. //! Here you can see how what that looks like: //! //! > Since [`Vec<T>`][std::vec::Vec] will consume instances of type `T` until it finds a error, it //! can never fail itself. You are therefore safe to unwrap the result. //! //! ``` //! use manger::{ Consumable, consume_struct }; //! //! struct EncasedInteger(i32); //! consume_struct!( //! EncasedInteger => [ //! > '[', //! value: i32, //! > ']'; //! (value) //! ] //! ); //! //! let source = "[3][-4][5]"; //! //! let (encased_integers, _) = <Vec<EncasedInteger>>::consume_from(source)?; //! //! let sum: i32 = encased_integers //! .iter() //! .map(|EncasedInteger(value)| value) //! .sum(); //! //! assert_eq!(sum, 4); //! # Ok::<(), manger::ConsumeError>(()) //! ``` //! //! #### OneOrMore //! //! The other easy way to do repetition is with [`OneOrMore<T>`][common::OneOrMore]. This allows for //! consuming 1 or more instances of type `T`. And again, type `T` has to have [`Consumable`] //! implemented. Here you can see what that looks like: //! //! ``` //! use manger::{ Consumable, consume_struct }; //! use manger::common::OneOrMore; //! //! struct EncasedInteger(i32); //! consume_struct!( //! EncasedInteger => [ //! > '[', //! value: i32, //! > ']'; //! (value) //! ] //! ); //! //! let source = "[3][-4][5]"; //! //! let (encased_integers, _) = <OneOrMore<EncasedInteger>>::consume_from(source)?; //! //! let product: i32 = encased_integers //! .into_iter() //! .map(|EncasedInteger(value)| value) //! .product(); //! //! assert_eq!(product, -60); //! # Ok::<(), manger::ConsumeError>(()) //! ``` //! //! ### Optional value //! //! To express optional values you can use the [`Option<T>`][std::option::Option] standard rust //! type. This will consume either 0 or 1 of type `T`. //! //! > Since [`Option<T>`][std::option::Option] will consume a instance of type `T` if it finds no error, it //! can never fail itself. You are therefore safe to unwrap the result. //! //! ``` //! use manger::consume_struct; //! use manger::chars; //! //! struct PossiblyEncasedInteger(i32); //! consume_struct!( //! PossiblyEncasedInteger => [ //! : Option<chars::OpenParenthese>, //! value: i32, //! : Option<chars::CloseParenthese>; //! (value) //! ] //! ); //! ``` //! //! ### Recursion //! //! Another common pattern seen within combinatoric parsers is recursion. Since rust types need to //! have a predefined since, we cannot do direct type recursion and we need to do heap allocation //! with the [`Box<T>`][std::box::Box] type from the standard library. We can make a prefixed //! math expression parser as followed: //! //! ``` //! use manger::consume_enum; //! use manger::common::{OneOrMore, Whitespace}; //! //! enum Expression { //! Times(Box<Expression>, Box<Expression>), //! Plus(Box<Expression>, Box<Expression>), //! Constant(u32), //! } //! //! consume_enum!( //! Expression { //! Times => [ //! > '*', //! : OneOrMore<Whitespace>, //! left: Box<Expression>, //! : OneOrMore<Whitespace>, //! right: Box<Expression>; //! (left, right) //! ], //! Plus => [ //! > '+', //! : OneOrMore<Whitespace>, //! left: Box<Expression>, //! : OneOrMore<Whitespace>, //! right: Box<Expression>; //! (left, right) //! ], //! Constant => [ //! value: u32; //! (value) //! ] //! } //! ); //! ``` //! //! ### Whitespace //! //! For whitespace we can use the [`manger::common::Whitespace`] struct. This will consume any //! utf-8 character that is identified as a whitespace character by the [`char::is_whitespace`] //! function. //! //! ### Either //! //! If two possibilities are present for consuming there are two options to choose from. Both are //! valid in certain scenarios. //! //! ## Macro //! //! Using the [`consume_enum`] you can create an struct which can be consuming in a number of //! options and you can see which option was selected. If you need to see which of the different //! options was selected, this should be your choice. //! //! ## Either<L, R> //! //! You can also use the [`Either<L, R>`][either::Either] type to represent the either //! relationship. This option is preferred if we do not care about which option is selected. #[doc(inline)] pub use error::{ConsumeError, ConsumeErrorType}; /// Trait that defines whether a trait can be interpretted for a `source` string or not. It is the /// trait that defines most behaviour for [manger][crate]. /// /// [`Consumable`] allows for taking a part of the start of a `source` string and turn it into a /// instance of `Self` and the unconsumed part of the `source`. /// /// # Implementation /// /// Most of the implementations for this trait can be done with the [`consume_struct`] or /// [`consume_enum`]. It is also the preferred way to implement [`Consumable`] for most types since /// it handles error handling properly as well. /// /// ## Custom implementations /// /// This trait can be implemented for types by implementing the /// [`consume_from`][Consumable::consume_from] function. The /// [`consume_from`][Consumable::consume_from] function takes a `source` string and outputs the /// instance of `Self` and the unconsumed part of the `source` or will return how the consuming /// failed. /// /// It is highly suggested that the implementation of consume_from takes into account /// [utf-8](https://en.wikipedia.org/wiki/UTF-8), since most functions in [manger][crate] work with /// the [utf-8](https://en.wikipedia.org/wiki/UTF-8) standard. This can be more easily done crates /// like [utf8-slice][utf8_slice], which allows for using utf-8 character indicices in slices /// instead of using byte indices. /// /// # Examples /// /// ``` /// use manger::{ Consumable, consume_struct }; /// /// let source = "[3][4][-5]"; /// /// struct EncasedInteger(i32); /// consume_struct!( /// EncasedInteger => [ /// > '[', /// value: i32, /// > ']'; /// (value) /// ] /// ); /// /// let product: i32 = EncasedInteger::consume_iter(source) /// .map(|EncasedInteger(value)| value) /// .product(); /// /// assert_eq!(product, -60); /// ``` pub trait Consumable: Sized { /// Attempt consume from `source` to form an item of `Self`. When consuming is /// succesful, it returns the item along with the unconsumed part of the source. /// When consuming is unsuccesful it returns the corresponding error. /// /// This is the core function to implement when implementing the /// [`Consumable`](#) trait. /// /// # Implementation note /// /// It is highly recommended to take into account UTF-8 characters. This is /// reasonably easy with `.chars()` on `&str` or with the crate /// [`utf8-slice`](https://crates.io/crates/utf8_slice). /// /// # Examples /// /// ``` /// use manger::Consumable; /// /// let source = "42 is the answer!"; /// /// let (answer, unconsumed) = u32::consume_from(source)?; /// /// assert_eq!(answer, 42); /// assert_eq!(unconsumed, " is the answer!"); /// # Ok::<(), manger::ConsumeError>(()) /// ``` fn consume_from(source: &str) -> Result<(Self, &str), ConsumeError>; /// Attempt consume from `source` to form an item of `Self`. When consuming is /// succesful, it returns the item along with the unconsumed part of the source /// and the amount of consumed characters. /// When consuming is unsuccesful it returns the corresponding error. /// /// # Note /// /// This counts UTF-8 characters and not byte indices. This can create some /// confusion when slicing afterwards. One can use a crate such as /// [`utf8-slice`](https://crates.io/crates/utf8_slice) to compensate for this. /// /// # Examples /// /// ``` /// use manger::Consumable; /// /// let source = "42 is the answer!"; /// /// let (answer, unconsumed, consumed_amount) = u32::consume_how_many_from(source)?; /// /// assert_eq!(answer, 42); /// assert_eq!(unconsumed, " is the answer!"); /// assert_eq!(consumed_amount, 2); /// # Ok::<(), manger::ConsumeError>(()) /// ``` fn consume_how_many_from(source: &str) -> Result<(Self, &str, usize), ConsumeError> { let start_len = utf8_slice::len(source); let (item, unconsumed) = Self::consume_from(source)?; let end_len = utf8_slice::len(unconsumed); Ok((item, unconsumed, start_len - end_len)) } /// Fetch a iterator of `source` to inorderly consume items of `Self`. /// /// # Examples /// /// ``` /// use manger::{ Consumable, consume_struct }; /// /// let source = "(3)(4)(5)"; /// /// struct EncasedInteger(u32); /// consume_struct!( /// EncasedInteger => [ /// > '(', /// value: u32, /// > ')'; /// (value) /// ] /// ); /// /// let product: u32 = EncasedInteger::consume_iter(source) /// .map(|EncasedInteger(value)| value) /// .product(); /// /// assert_eq!(product, 60); /// ``` fn consume_iter<'a>(source: &'a str) -> ConsumeIter<'a, Self> { ConsumeIter { phantom: std::marker::PhantomData, unconsumed: source, } } } /// Trait which allows for consuming of instances and literals from a string. /// /// This trait should be mostly used for types with a bijection to a string representation, /// which includes the `char` and `&str`. This does not include floating points, because /// "42" and "4.2e1" will both consume to 42. /// /// # Note /// /// For the reason mentioned before, this is not implemented for `f32` and `f64`. Similarly, /// this is also not implemented for `u8`, `u16`, `u32`, `u64`, `i8`, `i1 pub trait SelfConsumable { /// Attempt to consume a literal `item` from a `source` string. When consuming /// is succesful, it will return the unconsumed part of the `source`. When consuming /// fails, it will return an error. /// /// This is the core function implement when implementing [`SelfConsumable`](#). /// /// # Implementation note /// /// It is highly recommended to take into account UTF-8 characters. This is /// reasonably easy with `.chars()` on `&str` or with the crate /// [`utf8-slice`](https://crates.io/crates/utf8_slice). /// /// # Examples /// /// ``` /// use manger::{ Consumable, SelfConsumable }; /// /// let source = "scalar*42"; /// /// let unconsumed = <&str>::consume_item(source, &"scalar")?; /// assert_eq!(unconsumed, "*42"); /// /// let unconsumed = char::consume_item(unconsumed, &'*')?; /// assert_eq!(unconsumed, "42"); /// /// let (num, unconsumed) = u32::consume_from(unconsumed)?; /// assert_eq!(num, 42); /// assert_eq!(unconsumed, ""); /// # Ok::<(), manger::ConsumeError>(()) /// ``` fn consume_item<'a>(source: &'a str, item: &'_ Self) -> Result<&'a str, ConsumeError>; } /// Trait that exposes some functions for easier consuming syntax on `&str`. /// /// ConsumeSource is only implemented for `&str`. pub trait ConsumeSource: Sized { /// A shorthand for the [`consume_item`](trait.SelfConsumable.html#tymethod.consume_item). /// Here the `source` is `self` and the `item` is `literal`. /// /// # Examples /// /// ``` /// use manger::ConsumeSource; /// /// let source = "{42}"; /// /// let unconsumed = source.consume_lit(&'{')?; /// assert_eq!(unconsumed, "42}"); /// /// let (num, unconsumed) = unconsumed.consume::<u32>()?; /// assert_eq!(num, 42); /// assert_eq!(unconsumed, "}"); /// /// let unconsumed = unconsumed.consume_lit(&'}')?; /// assert_eq!(unconsumed, ""); /// # Ok::<(), manger::ConsumeError>(()) /// ``` fn consume_lit<T: SelfConsumable>(self, literal: &T) -> Result<Self, ConsumeError>; /// A shorthand for the [`consume_from`](trait.Consumable.html#tymethod.consume_from). /// Here the `source` is `self`. Returns how many utf-8 characters where consumed, when /// succesful. /// /// # Examples /// /// ``` /// use manger::ConsumeSource; /// /// let source = "{42}"; /// /// let unconsumed = source.consume_lit(&'{')?; /// assert_eq!(unconsumed, "42}"); /// /// let (num, unconsumed) = unconsumed.consume::<u32>()?; /// assert_eq!(num, 42); /// assert_eq!(unconsumed, "}"); /// /// let unconsumed = unconsumed.consume_lit(&'}')?; /// assert_eq!(unconsumed, ""); /// # Ok::<(), manger::ConsumeError>(()) /// ``` fn consume<T: Consumable>(self) -> Result<(T, Self), ConsumeError>; /// A shorthand for the [`consume_item`](trait.SelfConsumable.html#tymethod.consume_item). /// Here the `source` is `self` and the `item` is `literal`. /// /// Will mutate `source` to have the unconsumed part. /// /// # Examples /// /// ``` /// use manger::ConsumeSource; /// /// let mut source = "{42}"; /// /// source.mut_consume_lit(&'{')?; /// assert_eq!(source, "42}"); /// /// let num = source.mut_consume::<u32>()?; /// assert_eq!(num, 42); /// assert_eq!(source, "}"); /// /// source.mut_consume_lit(&'}')?; /// assert_eq!(source, ""); /// # Ok::<(), manger::ConsumeError>(()) /// ``` fn mut_consume_lit<T: SelfConsumable>(&mut self, literal: &T) -> Result<usize, ConsumeError>; /// A shorthand for the [`consume_from`](trait.Consumable.html#tymethod.consume_from). /// Here the `source` is `self`. /// /// Will mutate `source` to have the unconsumed part. /// /// # Examples /// /// ``` /// use manger::ConsumeSource; /// /// let mut source = "{42}"; /// /// source.mut_consume_lit(&'{')?; /// assert_eq!(source, "42}"); /// /// let num = source.mut_consume::<u32>()?; /// assert_eq!(num, 42); /// assert_eq!(source, "}"); /// /// source.mut_consume_lit(&'}')?; /// assert_eq!(source, ""); /// # Ok::<(), manger::ConsumeError>(()) /// ``` fn mut_consume<T: Consumable>(&mut self) -> Result<T, ConsumeError>; /// A shorthand for the [`consume_how_many_from`](trait.Consumable.html#tymethod.consume_from). /// Here the `source` is `self`. /// /// Will mutate `source` to have the unconsumed part. /// /// # Examples /// /// ``` /// use manger::ConsumeSource; /// /// let mut source = "{42}"; /// /// source.mut_consume_lit(&'{')?; /// assert_eq!(source, "42}"); /// /// let (num, amount) = source.mut_consume_by::<u32>()?; /// assert_eq!(num, 42); /// assert_eq!(amount, 2); /// assert_eq!(source, "}"); /// /// source.mut_consume_lit(&'}')?; /// assert_eq!(source, ""); /// # Ok::<(), manger::ConsumeError>(()) /// ``` fn mut_consume_by<T: Consumable>(&mut self) -> Result<(T, usize), ConsumeError>; } impl<'s> ConsumeSource for &'s str { fn consume_lit<T: SelfConsumable>(self, item: &T) -> Result<Self, ConsumeError> { <T>::consume_item(self, item) } fn consume<T: Consumable>(self) -> Result<(T, Self), ConsumeError> { <T>::consume_from(self) } fn mut_consume<T: Consumable>(&mut self) -> Result<T, ConsumeError> { let (item, unconsumed) = self.consume()?; *self = unconsumed; Ok(item) } fn mut_consume_lit<T: SelfConsumable>(&mut self, literal: &T) -> Result<usize, ConsumeError> { let length = utf8_slice::len(self); let unconsumed = self.consume_lit(literal)?; *self = unconsumed; Ok(length - utf8_slice::len(self)) } fn mut_consume_by<T: Consumable>(&mut self) -> Result<(T, usize), ConsumeError> { let length = utf8_slice::len(self); let (item, unconsumed) = self.consume()?; *self = unconsumed; Ok((item, length - utf8_slice::len(self))) } } /// Iterator over a `source` for a `Consumable` type `T`. /// /// Will consume items of type 'T' in the order of the `source`. /// /// # Examples /// /// ``` /// use manger::{ Consumable, consume_struct }; /// /// let source = "(3)(4)(5)"; /// /// struct EncasedInteger(u32); /// consume_struct!( /// EncasedInteger => [ /// > '(', /// value: u32, /// > ')'; /// (value) /// ] /// ); /// /// let product: u32 = EncasedInteger::consume_iter(source) /// .map(|EncasedInteger(value)| value) /// .product(); /// /// assert_eq!(product, 60); /// ``` #[derive(Debug)] pub struct ConsumeIter<'a, T> where T: Consumable, { phantom: std::marker::PhantomData<T>, unconsumed: &'a str, } impl<'a, T> Iterator for ConsumeIter<'a, T> where T: Consumable, { type Item = T; fn next(&mut self) -> Option<Self::Item> { let (item_option, unconsumed) = <Option<T>>::consume_from(self.unconsumed).unwrap(); self.unconsumed = unconsumed; item_option } } pub mod chars; pub mod common; mod either; mod enum_macro; mod error; mod floats; mod impls; mod integers; mod strs; mod struct_macro;