commit 00bd55874c7eeca1fe8307ee6f440eb6d381993a
Author: Jeremy Wall <jeremy@marzhillstudios.com>
Date:   Sun Sep 2 22:10:11 2018 -0500

    Initial Commit.

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..626bd18
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,6 @@
+/target
+**/*.rs.bk
+
+/target
+**/*.rs.bk
+Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..ac4da0f
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "abortable-parser"
+version = "0.1.0"
+authors = ["Jeremy Wall <jeremy@marzhillstudios.com>"]
+
+[dependencies]
diff --git a/src/iter.rs b/src/iter.rs
new file mode 100644
index 0000000..50af31a
--- /dev/null
+++ b/src/iter.rs
@@ -0,0 +1,51 @@
+//! Contains implementations of `InputIter`.
+use std::iter::Iterator;
+use std::fmt::Debug;
+
+use super::InputIter;
+
+/// Implements `InputIter` for any slice of T.
+#[derive(Debug)]
+pub struct SliceIter<'a, T: Debug + 'a> {
+    source: &'a [T],
+    offset: usize,
+}
+
+impl<'a, T: Debug + 'a> SliceIter<'a, T> {
+    /// new constructs a SliceIter from a Slice of T.
+    pub fn new(source: &'a [T]) -> Self {
+        SliceIter {
+            source: source,
+            offset: 0,
+        }
+    }
+}
+
+impl<'a, T: Debug + 'a> Iterator for SliceIter<'a, T> {
+    type Item = &'a T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        match self.source.get(self.offset) {
+            Some(item) => {
+                self.offset += 1;
+                Some(item)
+            },
+            None => None,
+        }
+    }
+}
+
+impl<'a, T: Debug + 'a> InputIter for SliceIter<'a, T> {
+    fn get_offset(&self) -> usize {
+        self.offset
+    }
+}
+
+impl<'a, T: Debug + 'a> Clone for SliceIter<'a, T> {
+    fn clone(&self) -> Self {
+        SliceIter {
+            source: self.source,
+            offset: self.offset,
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..ff73e1f
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,64 @@
+//! A parser combinator library with a focus on fully abortable parsing and error handling.
+use std::iter::Iterator;
+
+/// A Cloneable Iterator that can report an offset as a count of processed Items.
+pub trait InputIter: Iterator + Clone {
+    fn get_offset(&self) -> usize;
+}
+
+/// The result of a parsing attempt.
+#[derive(Debug)]
+pub enum Result<I: InputIter, O, E> {
+    /// Complete represents a successful match.
+    Complete(I, O),
+    /// Incomplete indicates input ended before a match could be completed.
+    /// It contains the offset at which the input ended before a match could be completed.
+    Incomplete(usize),
+    /// Fail represents a failed match.
+    Fail(E),
+    /// Abort represents a match failure that the parser cannot recover from.
+    Abort(E),
+}
+
+impl<I: InputIter, O, E> Result<I, O, E> {
+    /// Returns true if the Result is Complete.
+    pub fn is_complete(&self) -> bool {
+        if let &Result::Complete(_, _) = self {
+             return true;
+        }
+        return false;
+    }
+
+    /// Returns true if the Result is Incomoplete. 
+    pub fn is_incomplete(&self) -> bool {
+        if let &Result::Incomplete(_) = self {
+             return true;
+        }
+        return false;
+    }
+    
+    /// Returns true if the Result is Fail. 
+    pub fn is_fail(&self) -> bool {
+        if let &Result::Fail(_) = self {
+             return true;
+        }
+        return false;
+    }
+    
+    /// Returns true if the Result is Abort. 
+    pub fn is_abort(&self) -> bool {
+        if let &Result::Abort(_) = self {
+             return true;
+        }
+        return false;
+    }
+}
+
+pub use iter::SliceIter;
+
+#[macro_use]
+pub mod macros;
+pub mod iter;
+
+#[cfg(test)]
+mod test;
\ No newline at end of file
diff --git a/src/macros.rs b/src/macros.rs
new file mode 100644
index 0000000..83e0ee5
--- /dev/null
+++ b/src/macros.rs
@@ -0,0 +1,275 @@
+//! Contains the helper macros for abortable-parser.
+
+/// 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)
+    };
+}
+
+/// Turns Fails into Aborts. Allows you to turn any parse failure into a hard abort of the parser.
+#[macro_export]
+macro_rules! must {
+    ($i:expr, $f:ident!( $( $args:tt )* ) ) => {
+        match $f!($i, $($args)*) {
+            $crate::Result::Complete(i, o) => $crate::Result::Complete(i, o),
+            $crate::Result::Incomplete(offset) => $crate::Result::Incomplete(offset),
+            $crate::Result::Fail(e) => $crate::Result::Abort(e),
+            $crate::Result::Abort(e) => $crate::Result::Abort(e),
+        }
+    };
+    
+    ($i:expr, $f:ident) => {
+        must!($i, run!($f))
+    };
+}
+
+/// Turns Aborts into fails allowing you to trap and then convert an Abort into a normal Fail.
+#[macro_export]
+macro_rules! trap {
+    ($i:expr, $f:ident!( $( $args:tt )* ) ) => {
+        match $f!($i, $($args)*) {
+            $crate::Result::Complete(i, o) => $crate::Result::Complete(i, o),
+            $crate::Result::Incomplete(offset) => $crate::Result::Incomplete(offset),
+            $crate::Result::Fail(e) => $crate::Result::Fail(e),
+            $crate::Result::Abort(e) => $crate::Result::Fail(e),
+        }
+    };
+    
+    ($i:expr, $f:ident) => {
+        trap!($i, run!($f))
+    };
+}
+
+/// Turns Fails and Incompletes into Aborts. It uses an error factory
+/// to construct the errors for the Incomplete case.
+#[macro_export]
+macro_rules! must_complete {
+    ($i:expr, $efn:expr, $f:ident!( $( $args:tt )* ) ) => {
+        match $f!($i, $($args)*) {
+            $crate::Result::Complete(i, o) => $crate::Result::Complete(i, o),
+            $crate::Result::Incomplete(offset) => $crate::Result::Abort($efn(offset)),
+            $crate::Result::Fail(e) => $crate::Result::Abort(e),
+            $crate::Result::Abort(e) => $crate::Result::Abort(e),
+        }
+    };
+    
+    ($i:expr, $efn:expr, $f:ident) => {
+        must_complete!($i, $efn, run!($f))
+    };
+}
+
+/// Captures a sequence of sub parsers output.
+#[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(offset) => {
+                Result::Incomplete(offset)
+            }
+            $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(offset) => {
+                Result::Incomplete(offset)
+            }
+            $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), $( $rest )* )
+    };
+
+    // FIXME(jwall): Make this internal only. 
+    // Our Terminal condition
+    ($i:expr, ( $($rest:tt)* ) ) => {
+        Result::Complete($i, ($($rest)*))
+    };
+}
+
+/// Returns the output of the first sub parser to succeed.
+#[macro_export]
+macro_rules! either {
+    // Initialization case.
+    ($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(i) => {
+                Result::Incomplete(i)
+            }
+            // 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(i) => {
+                Result::Incomplete(i)
+            }
+            // 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), $( $rest )* )
+    }
+}
+
+/// Treats a sub parser as optional. It returns Some(output) for a successful match
+/// and None for Fails.
+#[macro_export]
+macro_rules! optional {
+    ($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();
+        match $f!($i, $($args)*) {
+            $crate::Result::Complete(i, o) => {
+                Result::Complete(i, Some(o))
+            }
+            // Incomplete could still work possibly parse.
+            $crate::Result::Incomplete(i) => {
+                Result::Incomplete(i)
+            }
+            // Fail just means it didn't match.
+            $crate::Result::Fail(_) => {
+                Result::Complete(_i, None)
+            },
+            // Aborts are hard failures that the parser can't recover from.
+            $crate::Result::Abort(e) => Result::Abort(e),
+        }
+    }};
+}
+
+/// Runs a single parser repeating 0 or mre times and returns a possibly empty
+/// vector of the parsed results.
+#[macro_export]
+macro_rules! repeat {
+    ($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))
+    };
+}
\ No newline at end of file
diff --git a/src/test.rs b/src/test.rs
new file mode 100644
index 0000000..b6e3d1f
--- /dev/null
+++ b/src/test.rs
@@ -0,0 +1,269 @@
+use super::iter::SliceIter;
+use super::{Result, InputIter};
+
+#[test]
+fn test_slice_iter() {
+    let input_str = "foo";
+    let mut iter = SliceIter::new(input_str.as_bytes());
+    let cloned = iter.clone();
+    assert_eq!(0, iter.get_offset());
+    let mut out = Vec::new();
+    loop {
+        let b = match iter.next() {
+            None => break,
+            Some(b) => b,
+        };
+        out.push(b.clone());
+    }
+    assert_eq!(3, out.len());
+    assert_eq!('f' as u8, out[0]);
+    assert_eq!('o' as u8, out[1]);
+    assert_eq!('o' as u8, out[2]);
+    assert_eq!(3, iter.get_offset());
+    
+    out = Vec::new();
+    for b in cloned {
+        out.push(b.clone());
+    }
+    assert_eq!(3, out.len());
+    assert_eq!('f' as u8, out[0]);
+    assert_eq!('o' as u8, out[1]);
+    assert_eq!('o' as u8, out[2]);
+}
+
+fn will_fail(_: SliceIter<u8>) -> Result<SliceIter<u8>, String, String>  {
+    Result::Fail("AAAAHHH!!!".to_string())
+}
+
+fn parse_byte(mut i: SliceIter<u8>) -> Result<SliceIter<u8>, u8, String> {
+    match i.next() {
+        Some(b) => Result::Complete(i, *b),
+        None => Result::Incomplete(i.get_offset()),
+    }
+}
+
+fn will_not_complete(_: SliceIter<u8>) -> Result<SliceIter<u8>, String, String> {
+    Result::Incomplete(0)
+}
+
+fn parse_three(i: SliceIter<u8>) -> Result<SliceIter<u8>, String, String> {
+    let mut _i = i.clone();
+    let mut out = String::new();
+    loop {
+        let b = match _i.next() {
+            None => break,
+            Some(b) => *b,
+        };
+        out.push(b as char);
+        if out.len() == 3 {
+            break;
+        }
+    }
+    if out.len() != 3 {
+        Result::Incomplete(_i.get_offset())
+    } else {
+        Result::Complete(_i, out)
+    }
+}
+
+#[test]
+fn test_must_fails() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = must!(iter, will_fail);
+    assert!(result.is_abort());
+}
+
+#[test]
+fn test_must_succeed() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = must!(iter, parse_byte);
+    assert!(result.is_complete());
+}
+
+#[test]
+fn test_trap_abort() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = trap!(iter, must!(will_fail));
+    assert!(result.is_fail(), format!("{:?}", result));
+}
+
+#[test]
+fn test_trap_incomplete() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = trap!(iter, will_not_complete);
+    assert!(result.is_incomplete(), format!("{:?}", result));
+}
+
+#[test]
+fn test_trap_fail() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = trap!(iter, will_fail);
+    assert!(result.is_fail(), format!("{:?}", result));
+}
+
+#[test]
+fn test_trap_complete() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = trap!(iter, parse_byte);
+    assert!(result.is_complete(), format!("{:?}", result));
+}
+
+#[test]
+fn test_must_complete() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let iter_fail = iter.clone();
+    let mut result = must_complete!(iter, |_| "AHHH".to_string(), will_not_complete);
+    assert!(result.is_abort());
+    result = must_complete!(iter_fail, |_| "AHHH".to_string(), will_fail);
+    assert!(result.is_abort());
+}
+
+#[test]
+fn test_do_each() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = do_each!(iter,
+        b1 => parse_byte,
+        _ => parse_byte,
+        b3 => parse_byte,
+        (b1, b3)
+    );
+    assert!(result.is_complete());
+    if let Result::Complete(_, o) = result {
+        assert_eq!('f' as u8, o.0);
+        assert_eq!('o' as u8, o.1);
+    } else {
+        assert!(false, "did not get a tuple of 2 items");
+    }
+}
+
+#[test]
+fn test_either_idents() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = either!(iter,
+        will_fail,
+        will_fail,
+        parse_three);
+    assert!(result.is_complete());
+    if let Result::Complete(_, o) = result {
+        assert_eq!("foo".to_string(), o);
+    } else {
+        assert!(false, "Didn't not successfully match");
+    }
+}
+
+#[test]
+fn test_either_macros() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = either!(iter,
+        run!(will_fail),
+        run!(will_fail),
+        run!(parse_three));
+    assert!(result.is_complete());
+    if let Result::Complete(_, o) = result {
+        assert_eq!("foo".to_string(), o);
+    } else {
+        assert!(false, "Didn't successfully match");
+    }
+}
+
+#[test]
+fn test_either_fail() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = either!(iter,
+        run!(will_fail),
+        run!(will_fail));
+    assert!(result.is_fail());
+}
+
+#[test]
+fn test_either_abort() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = either!(iter,
+        must!(will_fail),
+        parse_three,
+        run!(will_fail));
+    assert!(result.is_abort());
+}
+
+#[test]
+fn test_optional_some() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = optional!(iter, parse_byte);
+    assert!(result.is_complete());
+    if let Result::Complete(_, o) = result {
+        assert_eq!('f' as u8, o.unwrap());
+    } else {
+        assert!(false, "optional! did not complete");
+    }
+}
+
+#[test]
+fn test_optional_none() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = optional!(iter, will_fail);
+    assert!(result.is_complete());
+    if let Result::Complete(_, o) = result {
+        assert!(o.is_none(), "output was not none");
+    } else {
+        assert!(false, "optional! did not complete");
+    }
+}
+
+#[test]
+fn test_optional_abort() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = optional!(iter, must!(will_fail));
+    assert!(result.is_abort(), "optional did not abort");
+}
+
+#[test]
+fn test_repeat() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = repeat!(iter, parse_byte);
+    assert!(result.is_complete());
+    if let Result::Complete(_, o) = result {
+        assert_eq!(3, o.len());
+        assert_eq!('f' as u8, o[0]);
+        assert_eq!('o' as u8, o[1]);
+        assert_eq!('o' as u8, o[2]);
+    } else {
+        assert!(false, "repeat did not parse succesfully");
+    }
+}
+
+#[test]
+fn test_repeat_fail() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = repeat!(iter, will_fail);
+    assert!(result.is_complete());
+    if let Result::Complete(_, o) = result {
+        assert_eq!(0, o.len());
+    } else {
+        assert!(false, "repeat did not parse succesfully");
+    }
+}
+
+#[test]
+fn test_repeat_abort() {
+    let input_str = "foo";
+    let iter = SliceIter::new(input_str.as_bytes());
+    let result = repeat!(iter, must!(will_fail));
+    assert!(result.is_abort());
+}
\ No newline at end of file