Crate abortable_parser[−][src]
An opinionated parser combinator library with a focus on fully abortable parsing and easy error handling.
The approach to macro composition is heavily inspired by nom. It focuses on a simple API for combinators, and easy error handling.
We have a number of macros that assist in the gneration or handling of each type of error.
Simple parsing of a url.
#[macro_use] extern crate abortable_parser; use abortable_parser::iter::StrIter; use abortable_parser::{Result, eoi, ascii_ws}; make_fn!(proto<StrIter, &str>, do_each!( proto => until!(text_token!("://")), _ => must!(text_token!("://")), (proto) ) ); make_fn!(domain<StrIter, &str>, do_each!( // domains do not start with a slash _ => peek!(not!(text_token!("/"))), domain => until!(either!( discard!(text_token!("/")), discard!(ascii_ws), eoi)), (domain) ) ); make_fn!(path<StrIter, &str>, until!(either!(discard!(ascii_ws), eoi)) ); make_fn!(full_url<StrIter, (Option<&str>, Option<&str>, Option<&str>)>, do_each!( protocol => proto, // If we match the protocol then we must have a domain. // This is an example of an unrecoverable parsing error so we // abort with the must! macro if it doesn't match. domain => must!(domain), path => optional!(path), (Some(protocol), Some(domain), path) ) ); make_fn!(relative_url<StrIter, (Option<&str>, Option<&str>, Option<&str>)>, do_each!( _ => not!(either!(text_token!("//"), proto)), // we require a valid path for relative urls. path => path, (None, None, Some(path)) ) ); make_fn!(url<StrIter, (Option<&str>, Option<&str>, Option<&str>)>, either!( full_url, relative_url, ) ); let iter = StrIter::new("http://example.com/some/path "); let result = url(iter); assert!(result.is_complete()); if let Result::Complete(_, (proto, domain, path)) = result { assert!(proto.is_some()); assert!(domain.is_some()); if let Some(domain) = domain { assert_eq!(domain, "example.com"); } assert!(path.is_some()); if let Some(path) = path { assert_eq!(path, "/some/path"); } } let bad_input = StrIter::new("http:///some/path"); let bad_result = url(bad_input); assert!(bad_result.is_abort());
Re-exports
pub use combinators::*; |
pub use iter::SliceIter; |
pub use iter::StrIter; |
Modules
combinators |
Contains combinators that can assemble other matchers or combinators into more complex grammars. |
iter |
Contains implementations of |
Macros
complete |
Turns |
consume_all |
Consumes the input until the $rule fails and then returns the consumed input as a slice. |
discard |
Discards the output of a combinator rule when it completes and just returns |
do_each |
Captures a sequence of sub parsers output. |
either |
Returns the output of the first sub parser to succeed. |
input |
Helper macro that returns the input without consuming it. |
make_fn |
Constructs a function named $name that takes an input of type $i and produces an output of type $o. |
must |
Turns |
must_complete |
Turns |
not |
Turns a matcher into it's inverse, only succeeding if the the matcher returns a Fail. Does not consume it's input and only returns (). |
optional |
Treats a sub parser as optional. It returns Some(output) for a successful match and None for failures. |
peek |
Checks the given matcher without consuming the input. |
repeat |
Runs a single matcher repeating 0 or more times and returns a possibly empty vector of the parsed results. |
run |
Converts a function indentifier into a macro call. Useful when writing your own macro combinator. |
separated |
Parses separated list of items. |
text_token |
Convenience macro for looking for a specific text token in a byte input stream. |
trap |
Turns |
until |
Consumes an input until it reaches a term that the contained rule matches. It does not consume the subrule. |
wrap_err |
Wraps any Error return from a subparser in another error. Stores the position at this point in the parse tree allowing you to associate context with wrapped errors. |
Structs
Error |
The custom error type for use in |
Enums
Result |
The result of a parsing attempt. |
SpanRange |
SpanRange encompasses the valid Ops::Range types for use with the Span trait. |
Traits
InputIter |
A Cloneable Iterator that can report an offset as a count of processed Items. |
Offsetable |
A trait for types that can have an offset as a count of processed items. |
Peekable | |
Seekable | |
Span |
An input that can provide a span of a range of the input. |
TextPositionTracker |
Trait for Inputs that can track lines and columns in a text input. |