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// Copyright 2017 Jeremy Wall <jeremy@marzhillstudios.com>
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//! Contains combinators that can assemble other matchers or combinators into more complex grammars.
use super::{Error, InputIter, Result};
/// Turns a `Result` to it's inverse.
///
/// `Result::Fail` becomes `Result::Complete` and `Result::Complete` becomes `Result::Fail`.
/// You must pass in an iterator at the appropriate spot for the next combinator
/// to start at.
///
/// The `not!` macro provides syntactic sugar for using this combinator properly.
pub fn not<I, O>(i: I, result: Result<I, O>) -> Result<I, ()>
where
I: InputIter,
{
match result {
Result::Complete(i, _) => Result::Fail(Error::new(
"Matched on input when we shouldn't have.",
Box::new(i.clone()),
)),
Result::Abort(e) => Result::Abort(e),
Result::Incomplete(ctx) => Result::Incomplete(ctx),
Result::Fail(_) => Result::Complete(i, ()),
}
}
/// 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 ().
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// # use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// # use std::convert::From;
/// # fn main() {
/// # let iter: iter::SliceIter<u8> = "foo".into();
/// let tok = not!(iter, text_token!("bar"));
/// assert!(tok.is_complete());
/// if let Result::Complete(i, o) = tok {
/// assert_eq!(i.get_offset(), 0);
/// assert_eq!(o, ());
/// }
/// # }
/// ```
#[macro_export]
macro_rules! not {
($i:expr, $f:ident!( $( $args:tt )* ) ) => {{
let _i = $i.clone();
$crate::combinators::not(_i, trap!($i.clone(), $f!($($args)*)))
}};
($i:expr, $f:ident( $( $args:tt )* ) ) => {
not!($i, run!($f($($args)*)))
};
($i:expr, $f:ident) => {
not!($i, run!($f))
};
}
/// Checks the given matcher without consuming the input.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// # use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// # use std::convert::From;
/// # fn main() {
/// # let iter: iter::SliceIter<u8> = "foo".into();
/// let tok = peek!(iter, text_token!("foo"));
/// # assert!(tok.is_complete());
/// # if let Result::Complete(i, o) = tok {
/// # assert_eq!(i.get_offset(), 0);
/// # assert_eq!(o, "foo");
/// # }
/// # }
/// ```
#[macro_export]
macro_rules! peek {
($i:expr, $f:ident!( $( $args:tt )* ) ) => {{
use $crate::Result;
let _i = $i.clone();
match $f!(_i, $($args)*) {
Result::Complete(_, o) => Result::Complete($i, o),
Result::Incomplete(ctx) => Result::Incomplete(ctx),
Result::Abort(e) => Result::Abort(e),
Result::Fail(e) => Result::Fail(e),
}
}};
($i:expr, $f:ident( $( $args:tt )* ) ) => {
peek!($i, run!($f($($args)*)))
};
($i:expr, $f:ident) => {
peek!($i, run!($f))
};
}
/// Converts a function indentifier into a macro call. Useful when writing your own macro combinator.
#[macro_export]
macro_rules! run {
($i:expr, $f:ident) => {
$f($i)
};
}
/// Maps a `Result::Fail` to a `Result::Abort`.
///
/// It leaves the rest of the Result variants untouched.
///
/// The `must!` macro provided syntactice sugar for using this combinator.
pub fn must<I, O>(result: Result<I, O>) -> Result<I, O>
where
I: InputIter,
{
match result {
Result::Complete(i, o) => Result::Complete(i, o),
Result::Incomplete(ctx) => Result::Incomplete(ctx),
Result::Fail(e) => Result::Abort(e),
Result::Abort(e) => Result::Abort(e),
}
}
/// Turns `Result::Fail` into `Result::Abort`.
///
/// Allows you to turn any parse failure into a hard abort of the parser.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// use abortable_parser::iter;
/// # use abortable_parser::Result;
/// # use std::convert::From;
/// # fn main() {
///
/// let iter: iter::SliceIter<u8> = "foo".into();
///
/// let tok = must!(iter, text_token!("foo"));
/// # assert!(tok.is_complete());
///
/// let fail = must!(iter, text_token!("bar"));
/// # assert!(fail.is_abort());
/// # }
/// ```
#[macro_export]
macro_rules! must {
($i:expr, $f:ident!( $( $args:tt )* ) ) => {
$crate::combinators::must($f!($i, $($args)*))
};
($i:expr, $f:ident) => {
must!($i, run!($f))
};
}
#[macro_export]
/// Replaces the the sub error in a Fail case with one of your own errors.
macro_rules! with_err {
($i:expr, $f:ident!( $( $args:tt )* ), $e:expr) => {{
let _i = $i.clone();
match $f!($i, $($args)*) {
$crate::Result::Complete(i, o) => $crate::Result::Complete(i, o),
$crate::Result::Incomplete(ctx) => $crate::Result::Incomplete(ctx),
$crate::Result::Fail(e) => $crate::Result::Fail($crate::Error::new($e, Box::new(_i.clone()))),
$crate::Result::Abort(e) => $crate::Result::Abort($crate::Error::new($e, Box::new(_i.clone()))),
}
}};
($i:expr, $f:ident( $( $args:tt )* ), $e:expr ) => {
with_err!($i, run!($f($($args)*)), $e:expr)
};
($i:expr, $f:ident, $e:expr) => {
with_err!($i, run!($f), $e)
};
}
/// Wraps any Error return from a subparser in another error. Stores the position at
/// this point in the parse tree allowing you to associate context with wrapped errors.
#[macro_export]
macro_rules! wrap_err {
($i:expr, $f:ident!( $( $args:tt )* ), $e:expr) => {{
let _i = $i.clone();
match $f!($i, $($args)*) {
$crate::Result::Complete(i, o) => $crate::Result::Complete(i, o),
$crate::Result::Incomplete(ctx) => $crate::Result::Incomplete(ctx),
$crate::Result::Fail(e) => $crate::Result::Fail($crate::Error::caused_by($e, Box::new(e), Box::new(_i.clone()))),
$crate::Result::Abort(e) => $crate::Result::Abort($crate::Error::caused_by($e, Box::new(e), Box::new(_i.clone()))),
}
}};
($i:expr, $f:ident( $( $args:tt )* ), $e:expr ) => {
wrap_err!($i, run!($f($($args)*)), $e:expr)
};
($i:expr, $f:ident, $e:expr) => {
wrap_err!($i, run!($f), $e)
};
}
/// Traps a `Result::Abort` and converts it into a `Result::Fail`.
///
/// This is the semantic inverse of `must`.
///
/// The `trap!` macro provides syntactic sugar for using this combinator.
pub fn trap<I, O>(result: Result<I, O>) -> Result<I, O>
where
I: InputIter,
{
match result {
Result::Complete(i, o) => Result::Complete(i, o),
Result::Incomplete(ctx) => Result::Incomplete(ctx),
Result::Fail(e) => Result::Fail(e),
Result::Abort(e) => Result::Fail(e),
}
}
/// Turns `Result::Abort` into `Result::Fail` allowing you to trap and then convert any `Result::Abort`
/// into a normal Fail.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// # fn main() {
/// let input_str = "foo";
/// let iter = iter::SliceIter::new(input_str.as_bytes());
/// let result = trap!(iter, must!(text_token!("bar")));
/// # assert!(result.is_fail());
/// # }
/// ```
#[macro_export]
macro_rules! trap {
($i:expr, $f:ident!( $( $args:tt )* ) ) => {
$crate::combinators::trap($f!($i, $($args)*))
};
($i:expr, $f:ident) => {
trap!($i, run!($f))
};
}
/// Turns `Result::Fail` or `Result::Incomplete` into `Result::Abort`.
///
/// You must specify the error message to use in case the matcher is incomplete.
///
/// The must_complete! macro provides syntactic sugar for using this combinator.
pub fn must_complete<I, O>(result: Result<I, O>, msg: String) -> Result<I, O>
where
I: InputIter,
{
match result {
Result::Complete(i, o) => Result::Complete(i, o),
Result::Incomplete(ctx) => Result::Abort(Error::new(msg, Box::new(ctx))),
Result::Fail(e) => Result::Abort(e),
Result::Abort(e) => Result::Abort(e),
}
}
/// Turns `Result::Incomplete` into `Result::Fail`.
pub fn complete<I, O, S>(result: Result<I, O>, msg: S) -> Result<I, O>
where
I: InputIter,
S: Into<String>,
{
match result {
Result::Incomplete(ctx) => Result::Fail(Error::new(msg.into(), Box::new(ctx))),
Result::Complete(i, o) => Result::Complete(i, o),
Result::Fail(e) => Result::Fail(e),
Result::Abort(e) => Result::Abort(e),
}
}
/// Turns `Result::Incomplete` into `Result::Fail`.
#[macro_export]
macro_rules! complete {
($i:expr, $e:expr, $f:ident!( $( $args:tt )* ) ) => {
$crate::combinators::complete($f!($i, $($args)*), $e)
};
($i:expr, $efn:expr, $f:ident) => {
complete!($i, $efn, run!($f))
};
}
/// Turns `Result::Fail` and `Result::Incomplete` into `Result::Abort`.
///
/// You must specify the error message to use in case the matcher is incomplete.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// # fn main() {
/// let input_str = "foo";
/// let iter = iter::SliceIter::new(input_str.as_bytes());
/// let mut result = must_complete!(iter, "AHHH".to_string(), text_token!("fooooo"));
/// # assert!(result.is_abort());
/// # }
#[macro_export]
macro_rules! must_complete {
($i:expr, $e:expr, $f:ident!( $( $args:tt )* ) ) => {{
$crate::combinators::must_complete($f!($i.clone(), $($args)*), $e)
}};
($i:expr, $efn:expr, $f:ident) => {
must_complete!($i, $efn, run!($f))
};
}
/// Captures a sequence of sub parsers output.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// # fn main() {
/// let input_str = "(foobar)";
/// let iter = iter::SliceIter::new(input_str.as_bytes());
/// let result = do_each!(iter,
/// _ => text_token!("("),
/// foo => text_token!("foo"),
/// bar => text_token!("bar"),
/// _ => text_token!(")"),
/// (foo, bar) // This expression will be the result of the parse
/// );
/// # assert!(result.is_complete());
/// if let Result::Complete(_, o) = result {
/// assert_eq!("foo", o.0);
/// assert_eq!("bar", o.1);
/// }
/// # }
/// ```
///
/// Or alternatively rather than a tuple as the output you can return a single
/// expression.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// # use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// # fn main() {
/// # let input_str = "(foobar)";
/// # let iter = iter::SliceIter::new(input_str.as_bytes());
/// let result = do_each!(iter,
/// _ => text_token!("("),
/// foo => text_token!("foo"),
/// bar => text_token!("bar"),
/// _ => text_token!(")"),
/// (vec![foo, bar]) // Non tuple expression as a result.
/// );
/// # assert!(result.is_complete());
/// if let Result::Complete(_, o) = result {
/// assert_eq!(vec!["foo", "bar"], o);
/// }
/// # }
/// ```
///
/// The output from this combinator must be indicated by parentheses.
#[macro_export]
macro_rules! do_each {
($i:expr, $val:ident => $f:ident) => {
// This is a compile failure.
compile_error!("do_each! must end with a tuple capturing the results")
};
($i:expr, $val:ident => $f:ident!($( $args:tt )* ), $($rest:tt)* ) => {
// If any single one of these matchers fails then all of them are failures.
match $f!($i, $($args)*) {
$crate::Result::Complete(i, o) => {
let $val = o;
do_each!(i, $($rest)*)
}
$crate::Result::Incomplete(ctx) => {
Result::Incomplete(ctx)
}
$crate::Result::Fail(e) => Result::Fail(e),
$crate::Result::Abort(e) => Result::Abort(e),
}
};
($i:expr, _ => $f:ident!($( $args:tt )* ), $($rest:tt)* ) => {
// If any single one of these matchers fails then all of them are failures.
match $f!($i, $($args)*) {
$crate::Result::Complete(i, _) => {
do_each!(i, $($rest)*)
}
$crate::Result::Incomplete(ctx) => {
Result::Incomplete(ctx)
}
$crate::Result::Fail(e) => Result::Fail(e),
$crate::Result::Abort(e) => Result::Abort(e),
}
};
($i:expr, $val:ident => $f:ident, $($rest:tt)* ) => {
// If any single one of these matchers fails then all of them are failures.
do_each!($i, $val => run!($f), $( $rest )* )
};
($i:expr, _ => $f:ident, $($rest:tt)* ) => {
// If any single one of these matchers fails then all of them are failures.
do_each!($i, _ => run!($f), $( $rest )* )
};
// Our Terminal condition
($i:expr, ( $($rest:tt)* ) ) => {
Result::Complete($i, ($($rest)*))
};
}
/// Returns the output of the first sub parser to succeed.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// # fn main() {
/// let input_str = "foo";
/// let iter = iter::SliceIter::new(input_str.as_bytes());
/// let result = either!(iter, text_token!("bar"), text_token!("foo"));
/// # assert!(result.is_complete());
/// # if let Result::Complete(_, o) = result {
/// # assert_eq!("foo", o);
/// # } else {
/// # assert!(false, "either! did not complete");
/// # }
/// # }
#[macro_export]
macro_rules! either {
// Initialization case.
($i:expr, $f:ident!( $( $args:tt )* ), $( $rest:tt)* ) => { // 0
either!(__impl $i, $f!( $($args)* ), $($rest)*)
};
// Initialization case.
($i:expr, $f:ident, $($rest:tt)* ) => { // 1
either!(__impl $i, run!($f), $($rest)*)
};
// Initialization failure case.
($i:expr, $f:ident!( $( $args:tt )* )) => { // 2
compile_error!("Either requires at least two sub matchers.")
};
// Initialization failure case.
($i:expr, $f:ident) => { // 3
either!($i, run!($f))
};
// Termination clause
(__impl $i:expr, $f:ident) => { // 4
either!(__impl $i, run!($f))
};
// Termination clause
(__impl $i:expr, $f:ident,) => { // 5
either!(__impl $i, run!($f))
};
// Termination clause
(__impl $i:expr, $f:ident!( $( $args:tt )* ),) => { // 6
either!(__impl $i, $f!($($args)*) __end)
};
// Termination clause
(__impl $i:expr, $f:ident!( $( $args:tt )* )) => {{ // 7
match $f!($i, $($args)*) {
// The first one to match is our result.
$crate::Result::Complete(i, o) => {
Result::Complete(i, o)
}
// Incompletes may still be parseable.
$crate::Result::Incomplete(ctx) => {
Result::Incomplete(ctx)
}
// Fail means it didn't match so we are now done.
$crate::Result::Fail(e) => {
$crate::Result::Fail(e)
},
// Aborts are hard failures that the parser can't recover from.
$crate::Result::Abort(e) => Result::Abort(e),
}
}};
// Internal Loop Implementation
(__impl $i:expr, $f:ident!( $( $args:tt )* ), $( $rest:tt )* ) => {{ // 8
let _i = $i.clone();
match $f!($i, $($args)*) {
// The first one to match is our result.
$crate::Result::Complete(i, o) => {
Result::Complete(i, o)
}
// Incompletes may still be parseable.
$crate::Result::Incomplete(ctx) => {
Result::Incomplete(ctx)
}
// Fail means it didn't match so continue to next one.
$crate::Result::Fail(_) => {
either!(__impl _i, $($rest)*)
},
// Aborts are hard failures that the parser can't recover from.
$crate::Result::Abort(e) => Result::Abort(e),
}
}};
// Internal Loop Implementation
(__impl $i:expr, $f:ident, $( $rest:tt )* ) => { // 9
either!(__impl $i, run!($f), $( $rest )* )
}
}
/// Maps a `Result` to be optional.
///
/// `Result::Fail` maps to None and `Result::Complete` maps to Some. The rest of the
/// `Result` variants are left untouched. You must pass in the iterator that the
/// next matcher should use in the event of a fail.
///
/// The `optional!` macro provides some syntactice sugar for using this combinator
/// properly.
pub fn optional<I, O>(iter: I, result: Result<I, O>) -> Result<I, Option<O>>
where
I: InputIter,
{
match result {
Result::Complete(i, o) => Result::Complete(i, Some(o)),
// Incomplete could still work possibly parse.
Result::Incomplete(ctx) => Result::Incomplete(ctx),
// Fail just means it didn't match.
Result::Fail(_) => Result::Complete(iter, None),
// Aborts are hard failures that the parser can't recover from.
Result::Abort(e) => Result::Abort(e),
}
}
/// Treats a sub parser as optional. It returns Some(output) for a successful match
/// and None for failures.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// # fn main() {
/// let input_str = "foo";
/// let iter = iter::SliceIter::new(input_str.as_bytes());
/// let result = optional!(iter, text_token!("foo"));
/// # assert!(result.is_complete());
/// # if let Result::Complete(_, o) = result {
/// # assert_eq!("foo", o.unwrap());
/// # } else {
/// # assert!(false, "optional! did not complete");
/// # }
/// # }
#[macro_export]
macro_rules! optional {
($i:expr, $f:ident) => {
optional!(__impl $i, run!($f))
};
($i:expr, $f:ident!( $( $args:tt )* ) ) => {
optional!(__impl $i, $f!( $( $args )* ))
};
(__impl $i:expr, $f:ident!( $( $args:tt )* )) => {{
let _i = $i.clone();
$crate::combinators::optional(_i, $f!($i, $($args)*))
}};
}
/// Runs a single matcher repeating 0 or more times and returns a possibly empty
/// vector of the parsed results.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// # fn main() {
/// let input_str = "foofoo";
/// let iter = iter::SliceIter::new(input_str.as_bytes());
/// let result = repeat!(iter, text_token!("foo"));
/// # assert!(result.is_complete());
/// if let Result::Complete(_, o) = result {
/// assert_eq!(2, o.len());
/// assert_eq!("foo", o[0]);
/// assert_eq!("foo", o[1]);
/// }
/// # }
/// ```
#[macro_export]
macro_rules! repeat {
($i:expr, $f:ident!( $( $args:tt )* ) ) => {{
let mut _i = $i.clone();
let mut seq = Vec::new();
let mut opt_error = None;
loop {
let __i = _i.clone();
match $f!(_i, $($args)*) {
$crate::Result::Complete(i, o) => {
seq.push(o);
_i = i;
}
// Aborts are always a hard fail.
$crate::Result::Abort(e) => {
opt_error = Some($crate::Result::Abort(e));
_i = $i.clone();
break;
}
// Everything else just means we are finished parsing.
$crate::Result::Incomplete(_) => {
_i = __i;
break;
}
$crate::Result::Fail(_) => {
_i = __i;
break;
}
}
}
match opt_error {
Some(e) => e,
None => $crate::Result::Complete(_i, seq),
}
}};
($i:expr, $f:ident) => {
repeat!($i, run!($f))
};
}
/// Parses separated list of items.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// # fn main() {
/// let input_str = "foo,foo";
/// let iter = iter::SliceIter::new(input_str.as_bytes());
/// let result = separated!(iter, text_token!(","), text_token!("foo"));
/// # assert!(result.is_complete());
/// if let Result::Complete(_, o) = result {
/// assert_eq!(2, o.len());
/// assert_eq!("foo", o[0]);
/// assert_eq!("foo", o[1]);
/// }
/// # }
/// ```
#[macro_export]
macro_rules! separated {
($i:expr, $sep_rule:ident!( $( $sep_args:tt )* ), $item_rule:ident!( $( $item_args:tt )* ) ) => {{
use $crate::Result;
let _i = $i.clone();
// We require at least one item for our list
let head = $item_rule!($i.clone(), $($item_args)*);
match head {
Result::Incomplete(ctx) => Result::Incomplete(ctx),
Result::Fail(e) => Result::Fail(e),
Result::Abort(e) => Result::Abort(e),
Result::Complete(i,item) => {
let mut list = vec![item];
// Now we parse a repeat of sep_rule and item_rule.
let tail_result = repeat!(i,
do_each!(
_ => $sep_rule!($($sep_args)*),
item => $item_rule!($($item_args)*),
(item)
)
);
match tail_result {
Result::Fail(e) => Result::Fail(e),
Result::Incomplete(ctx) => Result::Incomplete(ctx),
Result::Abort(e) => Result::Abort(e),
Result::Complete(i, mut tail) => {
list.extend(tail.drain(0..));
Result::Complete(i, list)
}
}
}
}
}};
($i:expr, $sep_rule:ident, $item_rule:ident ) => {
separated!($i, run!($sep_rule), run!($item_rule))
};
($i:expr, $sep_rule:ident!( $( $args:tt )* ), $item_rule:ident ) => {
separated!($i, $sep_rule!($($args)*), run!($item_rule))
};
($i:expr, $sep_rule:ident, $item_rule:ident!( $( $args:tt )* ) ) => {
separated!($i, run!($sep_rule), $item_rule!($($args)*))
};
}
/// Convenience macro for looking for a specific text token in a byte input stream.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// use std::convert::From;
/// # fn main() {
/// let iter: iter::SliceIter<u8> = "foo bar".into();
/// let tok = text_token!(iter, "foo");
/// # assert!(tok.is_complete());
/// if let Result::Complete(i, o) = tok {
/// assert_eq!(i.get_offset(), 3);
/// assert_eq!(o, "foo");
/// }
/// # }
/// ```
#[macro_export]
macro_rules! text_token {
($i:expr, $e:expr) => {{
use $crate::Error;
use $crate::Result;
let mut _i = $i.clone();
let mut count = 0;
for expected in $e.bytes() {
let item = match _i.next() {
Some(item) => item,
None => break,
};
if item == &expected {
count += 1;
}
}
if count == $e.len() {
Result::Complete(_i.clone(), $e)
} else {
Result::Fail(Error::new(
format!("Expected {} but didn't get it.", $e),
Box::new($i.clone()),
))
}
}};
}
/// Consumes an input until it reaches a term that the contained rule matches.
/// It does not consume the subrule.
///
/// If the term never matches then returns incomplete.
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// use std::convert::From;
/// # fn main() {
/// let iter: iter::SliceIter<u8> = "foo;".into();
/// let tok = until!(iter, text_token!(";"));
/// # assert!(tok.is_complete());
/// if let Result::Complete(i, o) = tok {
/// assert_eq!(i.get_offset(), 3);
/// }
/// # }
/// ```
#[macro_export]
macro_rules! until {
($i:expr, $rule:ident!( $( $args:tt )* ) ) => {{
use $crate::{Result, Offsetable, Span, SpanRange};
let start_offset = $i.get_offset();
let mut _i = $i.clone();
let pfn = || {
loop {
match $rule!(_i.clone(), $($args)*) {
Result::Complete(_, _) => {
let range = SpanRange::Range(start_offset.._i.get_offset());
return Result::Complete(_i, $i.span(range));
},
Result::Abort(e) => return Result::Abort(e),
Result::Incomplete(ctx) => return Result::Incomplete(ctx),
Result::Fail(_) => {
// noop
}
}
if let None = _i.next() {
return Result::Incomplete(_i.clone());
}
}
};
pfn()
}};
($i:expr, $rule:ident) => {
until!($i, run!($rule))
};
}
/// Discards the output of a combinator rule when it completes and just returns `()`.
/// Leaves Failures, Aborts, and Incompletes untouched.
#[macro_export]
macro_rules! discard {
($i:expr, $rule:ident) => {
discard!($i, run!($rule))
};
($i:expr, $rule:ident!( $( $args:tt )* ) ) => {{
use $crate::Result;
match $rule!($i, $($args)*) {
Result::Complete(i, _) => Result::Complete(i, ()),
Result::Incomplete(ctx) => Result::Incomplete(ctx),
Result::Fail(e) => Result::Fail(e),
Result::Abort(e) => Result::Abort(e),
}
}};
}
/// Matches and returns any ascii charactar whitespace byte.
pub fn ascii_ws<'a, I: InputIter<Item = &'a u8>>(mut i: I) -> Result<I, u8> {
match i.next() {
Some(b) => {
if (*b as char).is_whitespace() {
Result::Complete(i, *b)
} else {
Result::Fail(Error::new(
"Not whitespace".to_string(),
Box::new(i.clone()),
))
}
}
None => Result::Fail(Error::new(
"Unexpected End Of Input".to_string(),
Box::new(i.clone()),
)),
}
}
/// Matches the end of input for any InputIter.
/// Returns `()` for any match.
pub fn eoi<I: InputIter>(i: I) -> Result<I, ()> {
let mut _i = i.clone();
match _i.next() {
Some(_) => Result::Fail(Error::new(
"Expected End Of Input".to_string(),
Box::new(i.clone()),
)),
None => Result::Complete(i, ()),
}
}
/// Constructs a function named $name that takes an input of type $i and produces an output
/// of type $o.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// # use abortable_parser::iter::StrIter;
/// make_fn!(myrule<StrIter, &str>,
/// text_token!("token")
/// );
/// ```
///
/// You can also specify that the function is public if so desired.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// # use abortable_parser::iter::StrIter;
/// make_fn!(pub otherrule<StrIter, &str>,
/// text_token!("other")
/// );
/// ```
#[macro_export]
macro_rules! make_fn {
($name:ident<$i:ty, $o:ty>, $rule:ident!($( $body:tt )* )) => {
fn $name(i: $i) -> $crate::Result<$i, $o> {
$rule!(i, $($body)*)
}
};
(pub $name:ident<$i:ty, $o:ty>, $rule:ident!($( $body:tt )* )) => {
pub fn $name(i: $i) -> $crate::Result<$i, $o> {
$rule!(i, $($body)*)
}
};
($name:ident<$i:ty, $o:ty>, $rule:ident) => {
make_fn!($name<$i, $o>, run!($rule));
};
(pub $name:ident<$i:ty, $o:ty>, $rule:ident) => {
make_fn!(pub $name<$i, $o>, run!($rule));
};
}
/// Helper macro that returns the input without consuming it.
///
/// Useful when you need to get the input and use it to retrieve
/// positional information like offset or line and column.
#[macro_export]
macro_rules! input {
($i:expr) => {
input!($i,)
};
($i:expr,) => {{
let _i = $i.clone();
$crate::Result::Complete($i, _i)
}};
}
/// Consumes the input until the $rule fails and then returns the consumed input as
/// a slice.
///
/// ```
/// # #[macro_use] extern crate abortable_parser;
/// use abortable_parser::iter;
/// # use abortable_parser::{Result, Offsetable};
/// # use abortable_parser::combinators::ascii_alpha;
/// use std::convert::From;
/// # fn main() {
/// let iter: iter::StrIter = "foo;".into();
/// let tok = consume_all!(iter, ascii_alpha);
/// # assert!(tok.is_complete());
/// if let Result::Complete(i, o) = tok {
/// assert_eq!(i.get_offset(), 3);
/// assert_eq!(o, "foo");
/// }
/// # }
/// ```
#[macro_export]
macro_rules! consume_all {
($i:expr, $rule:ident!( $( $args:tt )* ) ) => {{
use $crate::{Result, Offsetable, Span, SpanRange};
let start_offset = $i.get_offset();
let mut _i = $i.clone();
let pfn = || {
loop {
match $rule!(_i.clone(), $($args)*) {
Result::Complete(_, _) => {
// noop
},
Result::Abort(e) => return Result::Abort(e),
Result::Incomplete(ctx) => return Result::Incomplete(ctx),
Result::Fail(_) => {
let range = SpanRange::Range(start_offset.._i.get_offset());
return Result::Complete(_i, $i.span(range));
}
}
if let None = _i.next() {
return Result::Incomplete(_i.clone());
}
}
};
pfn()
}};
($i:expr, $rule:ident) => {
consume_all!($i, run!($rule))
}
}
/// ascii_digit parses a single ascii alphabetic or digit character from an InputIter of bytes.
#[inline(always)]
pub fn ascii_alphanumeric<'a, I: InputIter<Item = &'a u8>>(mut i: I) -> Result<I, u8> {
match i.next() {
Some(b) => {
let c = *b as char;
if c.is_ascii_alphabetic() || c.is_ascii_digit() {
Result::Complete(i, *b)
} else {
Result::Fail(Error::new(
"Not an alphanumeric character".to_string(),
Box::new(i.clone()),
))
}
}
None => Result::Fail(Error::new(
"Unexpected End Of Input.".to_string(),
Box::new(i.clone()),
)),
}
}
/// ascii_digit parses a single ascii digit character from an InputIter of bytes.
#[inline(always)]
pub fn ascii_digit<'a, I: InputIter<Item = &'a u8>>(mut i: I) -> Result<I, u8> {
match i.next() {
Some(b) => {
if (*b as char).is_ascii_digit() {
Result::Complete(i, *b)
} else {
Result::Fail(Error::new(
"Not an digit character".to_string(),
Box::new(i.clone()),
))
}
}
None => Result::Fail(Error::new(
"Unexpected End Of Input.".to_string(),
Box::new(i.clone()),
)),
}
}
/// ascii_alpha parses a single ascii alphabet character from an InputIter of bytes.
#[inline(always)]
pub fn ascii_alpha<'a, I: InputIter<Item = &'a u8>>(mut i: I) -> Result<I, u8> {
match i.next() {
Some(b) => {
if (*b as char).is_ascii_alphabetic() {
Result::Complete(i, *b)
} else {
Result::Fail(Error::new(
"Not an alpha character".to_string(),
Box::new(i.clone()),
))
}
}
None => Result::Fail(Error::new(
"Unexpected End Of Input.".to_string(),
Box::new(i.clone()),
)),
}
}
// TODO(jwall): We need a helper to convert Optional into failures.
// TODO(jwall): We need a helper to convert std::result::Result into failures.