refactor progress

Cargo.toml

@@ -15,6 +15,7 @@ license = "Unlicense/MIT"
 
 [dependencies]
 docopt = "0.6"
+grep = { version = "0.1", path = "grep" }
 memchr = "0.1"
 memmap = "0.2"
 regex = { version = "0.1", path = "/home/andrew/rust/regex" }

grep/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+publish = false
+name = "grep"
+version = "0.1.0"  #:version
+authors = ["Andrew Gallant <jamslam@gmail.com>"]
+description = """
+Fast line oriented regex searching as a library.
+"""
+documentation = "https://github.com/BurntSushi/xrep"
+homepage = "https://github.com/BurntSushi/xrep"
+repository = "https://github.com/BurntSushi/xrep"
+readme = "README.md"
+keywords = ["regex", "grep", "egrep", "search", "pattern"]
+license = "Unlicense/MIT"
+
+[dependencies]
+memchr = "0.1"
+memmap = "0.2"
+regex = { version = "0.1", path = "/home/andrew/rust/regex" }
+regex-syntax = { version = "0.3.1", path = "/home/andrew/rust/regex/regex-syntax" }

grep/src/lib.rs

@@ -0,0 +1,72 @@
+extern crate memchr;
+extern crate regex;
+extern crate regex_syntax as syntax;
+
+use std::error;
+use std::fmt;
+use std::result;
+
+pub use search::{Grep, GrepBuilder};
+
+mod literals;
+mod nonl;
+mod search;
+
+/// Result is a convenient type alias that fixes the type of the error to
+/// the `Error` type defined in this crate.
+pub type Result<T> = result::Result<T, Error>;
+
+/// Error enumerates the list of possible error conditions when building or
+/// using a `Grep` line searcher.
+#[derive(Debug)]
+pub enum Error {
+    /// An error from parsing or compiling a regex.
+    Regex(regex::Error),
+    /// This error occurs when an illegal literal was found in the regex
+    /// pattern. For example, if the line terminator is `\n` and the regex
+    /// pattern is `\w+\n\w+`, then the presence of `\n` will cause this error.
+    LiteralNotAllowed(char),
+    #[doc(hidden)]
+    __Nonexhaustive,
+}
+
+impl error::Error for Error {
+    fn description(&self) -> &str {
+        match *self {
+            Error::Regex(ref err) => err.description(),
+            Error::LiteralNotAllowed(_) => "use of forbidden literal",
+            Error::__Nonexhaustive => unreachable!(),
+        }
+    }
+
+    fn cause(&self) -> Option<&error::Error> {
+        match *self {
+            Error::Regex(ref err) => err.cause(),
+            _ => None,
+        }
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Error::Regex(ref err) => err.fmt(f),
+            Error::LiteralNotAllowed(chr) => {
+                write!(f, "Literal '{}' not allowed.", chr)
+            }
+            Error::__Nonexhaustive => unreachable!(),
+        }
+    }
+}
+
+impl From<regex::Error> for Error {
+    fn from(err: regex::Error) -> Error {
+        Error::Regex(err)
+    }
+}
+
+impl From<syntax::Error> for Error {
+    fn from(err: syntax::Error) -> Error {
+        Error::Regex(regex::Error::Syntax(err))
+    }
+}

grep/src/literals.rs

@@ -25,11 +25,16 @@ impl LiteralSets {
         }
     }
 
-    pub fn to_matcher(&self) -> Option<Regex> {
+    pub fn to_regex(&self) -> Option<Regex> {
         if self.prefixes.all_complete() && !self.prefixes.is_empty() {
             // When this is true, the regex engine will do a literal scan.
             return None;
         }
+
+        // Out of inner required literals, prefixes and suffixes, which one
+        // is the longest? We pick the longest to do fast literal scan under
+        // the assumption that a longer literal will have a lower false
+        // positive rate.
         let pre_lcp = self.prefixes.longest_common_prefix();
         let pre_lcs = self.prefixes.longest_common_suffix();
         let suf_lcp = self.suffixes.longest_common_prefix();
@@ -70,32 +75,33 @@ fn union_required(expr: &Expr, lits: &mut Literals) {
             let s: String = chars.iter().cloned().collect();
             lits.cross_add(s.as_bytes());
         }
-        Literal { ref chars, casei: true } => {
+        Literal { casei: true, .. } => {
             lits.cut();
         }
         LiteralBytes { ref bytes, casei: false } => {
             lits.cross_add(bytes);
         }
-        LiteralBytes { ref bytes, casei: true } => {
+        LiteralBytes { casei: true, .. } => {
             lits.cut();
         }
-        Class(ref cls) => {
+        Class(_) => {
             lits.cut();
         }
-        ClassBytes(ref cls) => {
+        ClassBytes(_) => {
             lits.cut();
         }
         Group { ref e, .. } => {
             union_required(&**e, lits);
         }
-        Repeat { ref e, r: Repeater::ZeroOrOne, .. } => lits.cut(),
-        Repeat { ref e, r: Repeater::ZeroOrMore, .. } => lits.cut(),
+        Repeat { r: Repeater::ZeroOrOne, .. } => lits.cut(),
+        Repeat { r: Repeater::ZeroOrMore, .. } => lits.cut(),
         Repeat { ref e, r: Repeater::OneOrMore, .. } => {
             union_required(&**e, lits);
             lits.cut();
         }
         Repeat { ref e, r: Repeater::Range { min, max }, greedy } => {
-            repeat_range_literals(&**e, min, max, greedy, lits, union_required);
+            repeat_range_literals(
+                &**e, min, max, greedy, lits, union_required);
         }
         Concat(ref es) if es.is_empty() => {}
         Concat(ref es) if es.len() == 1 => union_required(&es[0], lits),
@@ -131,7 +137,7 @@ fn repeat_range_literals<F: FnMut(&Expr, &mut Literals)>(
     e: &Expr,
     min: u32,
     max: Option<u32>,
-    greedy: bool,
+    _greedy: bool,
     lits: &mut Literals,
     mut f: F,
 ) {

grep/src/nonl.rs

@@ -0,0 +1,65 @@
+use syntax::Expr;
+
+use {Error, Result};
+
+/// Returns a new expression that is guaranteed to never match the given
+/// ASCII character.
+///
+/// If the expression contains the literal byte, then an error is returned.
+///
+/// If `byte` is not an ASCII character (i.e., greater than `0x7F`), then this
+/// function panics.
+pub fn remove(expr: Expr, byte: u8) -> Result<Expr> {
+    use syntax::Expr::*;
+    assert!(byte <= 0x7F);
+    let chr = byte as char;
+    assert!(chr.len_utf8() == 1);
+
+    Ok(match expr {
+        Literal { chars, casei } => {
+            if chars.iter().position(|&c| c == chr).is_some() {
+                return Err(Error::LiteralNotAllowed(chr));
+            }
+            Literal { chars: chars, casei: casei }
+        }
+        LiteralBytes { bytes, casei } => {
+            if bytes.iter().position(|&b| b == byte).is_some() {
+                return Err(Error::LiteralNotAllowed(chr));
+            }
+            LiteralBytes { bytes: bytes, casei: casei }
+        }
+        AnyChar => AnyCharNoNL,
+        AnyByte => AnyByteNoNL,
+        Class(mut cls) => {
+            cls.remove(chr);
+            Class(cls)
+        }
+        ClassBytes(mut cls) => {
+            cls.remove(byte);
+            ClassBytes(cls)
+        }
+        Group { e, i, name } => {
+            Group {
+                e: Box::new(try!(remove(*e, byte))),
+                i: i,
+                name: name,
+            }
+        }
+        Repeat { e, r, greedy } => {
+            Repeat {
+                e: Box::new(try!(remove(*e, byte))),
+                r: r,
+                greedy: greedy,
+            }
+        }
+        Concat(exprs) => {
+            Concat(try!(
+                exprs.into_iter().map(|e| remove(e, byte)).collect()))
+        }
+        Alternate(exprs) => {
+            Alternate(try!(
+                exprs.into_iter().map(|e| remove(e, byte)).collect()))
+        }
+        e => e,
+    })
+}

grep/src/search.rs

@@ -0,0 +1,307 @@
+use std::io;
+
+use memchr::{memchr, memrchr};
+use regex::bytes::{Regex, RegexBuilder};
+use syntax;
+
+use literals::LiteralSets;
+use nonl;
+use Result;
+
+#[derive(Clone, Debug)]
+pub struct Grep {
+    re: Regex,
+    required: Option<Regex>,
+    opts: Options,
+}
+
+#[derive(Clone, Debug)]
+pub struct GrepBuilder {
+    pattern: String,
+    opts: Options,
+}
+
+#[derive(Clone, Debug)]
+struct Options {
+    case_insensitive: bool,
+    lines: bool,
+    locations: bool,
+    line_terminator: u8,
+    size_limit: usize,
+    dfa_size_limit: usize,
+}
+
+impl Default for Options {
+    fn default() -> Options {
+        Options {
+            case_insensitive: false,
+            lines: false,
+            locations: false,
+            line_terminator: b'\n',
+            size_limit: 10 * (1 << 20),
+            dfa_size_limit: 10 * (1 << 20),
+        }
+    }
+}
+
+impl GrepBuilder {
+    /// Create a new builder for line searching.
+    ///
+    /// The pattern given should be a regular expression. The precise syntax
+    /// supported is documented on the regex crate.
+    pub fn new(pattern: &str) -> GrepBuilder {
+        GrepBuilder {
+            pattern: pattern.to_string(),
+            opts: Options::default(),
+        }
+    }
+
+    /// Sets whether line numbers are reported for each match.
+    ///
+    /// When enabled (disabled by default), every matching line is tagged with
+    /// its corresponding line number accoring to the line terminator that is
+    /// set. Note that this requires extra processing which can slow down
+    /// search.
+    pub fn line_numbers(mut self, yes: bool) -> GrepBuilder {
+        self.opts.lines = yes;
+        self
+    }
+
+    /// Set whether precise match locations are reported for each matching
+    /// line.
+    ///
+    /// When enabled (disabled by default), every match of the regex on each
+    /// matchling line is reported via byte offsets. Note that this requires
+    /// extra processing which can slow down search.
+    pub fn locations(mut self, yes: bool) -> GrepBuilder {
+        self.opts.locations = yes;
+        self
+    }
+
+    /// Set the line terminator.
+    ///
+    /// The line terminator can be any ASCII character and serves to delineate
+    /// the match boundaries in the text searched.
+    ///
+    /// This panics if `ascii_byte` is greater than `0x7F` (i.e., not ASCII).
+    pub fn line_terminator(mut self, ascii_byte: u8) -> GrepBuilder {
+        assert!(ascii_byte <= 0x7F);
+        self.opts.line_terminator = ascii_byte;
+        self
+    }
+
+    /// Set the case sensitive flag (`i`) on the regex.
+    pub fn case_insensitive(mut self, yes: bool) -> GrepBuilder {
+        self.opts.case_insensitive = yes;
+        self
+    }
+
+    /// Set the approximate size limit of the compiled regular expression.
+    ///
+    /// This roughly corresponds to the number of bytes occupied by a
+    /// single compiled program. If the program exceeds this number, then a
+    /// compilation error is returned.
+    pub fn size_limit(mut self, limit: usize) -> GrepBuilder {
+        self.opts.size_limit = limit;
+        self
+    }
+
+    /// Set the approximate size of the cache used by the DFA.
+    ///
+    /// This roughly corresponds to the number of bytes that the DFA will use
+    /// while searching.
+    ///
+    /// Note that this is a per thread limit. There is no way to set a global
+    /// limit. In particular, if a regex is used from multiple threads
+    /// simulanteously, then each thread may use up to the number of bytes
+    /// specified here.
+    pub fn dfa_size_limit(mut self, limit: usize) -> GrepBuilder {
+        self.opts.dfa_size_limit = limit;
+        self
+    }
+
+    /// Create a line searcher.
+    ///
+    /// If there was a problem parsing or compiling the regex with the given
+    /// options, then an error is returned.
+    pub fn create(self) -> Result<Grep> {
+        let expr = try!(self.parse());
+        let literals = LiteralSets::create(&expr);
+        let re = try!(
+            RegexBuilder::new(&expr.to_string())
+                .case_insensitive(self.opts.case_insensitive)
+                .multi_line(true)
+                .unicode(true)
+                .size_limit(self.opts.size_limit)
+                .dfa_size_limit(self.opts.dfa_size_limit)
+                .compile()
+        );
+        Ok(Grep {
+            re: re,
+            required: literals.to_regex(),
+            opts: self.opts,
+        })
+    }
+
+    /// Parses the underlying pattern and ensures the pattern can never match
+    /// the line terminator.
+    fn parse(&self) -> Result<syntax::Expr> {
+        let expr =
+            try!(syntax::ExprBuilder::new()
+                 .allow_bytes(true)
+                 .unicode(true)
+                 .parse(&self.pattern));
+        Ok(try!(nonl::remove(expr, self.opts.line_terminator)))
+    }
+}
+
+impl Grep {
+    pub fn iter<'b, 's>(&'s self, buf: &'b [u8]) -> Iter<'b, 's> {
+        Iter {
+            searcher: self,
+            buf: buf,
+            start: 0,
+        }
+    }
+
+    pub fn read_match(
+        &self,
+        mat: &mut Match,
+        buf: &[u8],
+        mut start: usize,
+    ) -> bool {
+        if start >= buf.len() {
+            return false;
+        }
+        if let Some(ref req) = self.required {
+            while start < buf.len() {
+                let e = match req.shortest_match(&buf[start..]) {
+                    None => return false,
+                    Some(e) => start + e,
+                };
+                let (prevnl, nextnl) = self.find_line(buf, e, e);
+                match self.re.shortest_match(&buf[prevnl..nextnl]) {
+                    None => {
+                        start = nextnl + 1;
+                        continue;
+                    }
+                    Some(_) => {
+                        self.fill_match(mat, prevnl, nextnl);
+                        return true;
+                    }
+                }
+            }
+            false
+        } else {
+            let e = match self.re.shortest_match(&buf[start..]) {
+                None => return false,
+                Some(e) => start + e,
+            };
+            let (s, e) = self.find_line(buf, e, e);
+            self.fill_match(mat, s, e);
+            true
+        }
+    }
+
+    fn fill_match(&self, mat: &mut Match, start: usize, end: usize) {
+        mat.start = start;
+        mat.end = end;
+    }
+
+    fn find_line(&self, buf: &[u8], s: usize, e: usize) -> (usize, usize) {
+        (self.find_line_start(buf, s), self.find_line_end(buf, e))
+    }
+
+    fn find_line_start(&self, buf: &[u8], pos: usize) -> usize {
+        memrchr(self.opts.line_terminator, &buf[0..pos]).map_or(0, |i| i + 1)
+    }
+
+    fn find_line_end(&self, buf: &[u8], pos: usize) -> usize {
+        memchr(self.opts.line_terminator, &buf[pos..])
+            .map_or(buf.len(), |i| pos + i)
+    }
+}
+
+#[derive(Clone, Debug, Default, Eq, PartialEq)]
+pub struct Match {
+    start: usize,
+    end: usize,
+    line: Option<usize>,
+    locations: Vec<(usize, usize)>,
+}
+
+impl Match {
+    pub fn new() -> Match {
+        Match::default()
+    }
+
+    /// Return the starting byte offset of the line that matched.
+    #[inline]
+    pub fn start(&self) -> usize {
+        self.start
+    }
+
+    /// Return the ending byte offset of the line that matched.
+    #[inline]
+    pub fn end(&self) -> usize {
+        self.end
+    }
+
+    /// Return the line number that this match corresponds to.
+    ///
+    /// Note that this is `None` if line numbers aren't being computed. Line
+    /// number tracking can be enabled using `GrepBuilder`.
+    #[inline]
+    pub fn line(&self) -> Option<usize> {
+        self.line
+    }
+
+    /// Return the exact start and end locations (in byte offsets) of every
+    /// regex match in this line.
+    ///
+    /// Note that this always returns an empty slice if exact locations aren't
+    /// computed. Exact location tracking can be enabled using `GrepBuilder`.
+    #[inline]
+    pub fn locations(&self) -> &[(usize, usize)] {
+        &self.locations
+    }
+}
+
+pub struct Iter<'b, 's> {
+    searcher: &'s Grep,
+    buf: &'b [u8],
+    start: usize,
+}
+
+impl<'b, 's> Iterator for Iter<'b, 's> {
+    type Item = Match;
+
+    fn next(&mut self) -> Option<Match> {
+        let mut mat = Match::default();
+        if !self.searcher.read_match(&mut mat, self.buf, self.start) {
+            self.start = self.buf.len();
+            return None;
+        }
+        self.start = mat.end + 1;
+        Some(mat)
+    }
+}
+
+pub struct GrepBuffered<'g, B> {
+    grep: &'g Grep,
+    buf: B,
+    start: usize,
+}
+
+impl<'g, B: BufRead> GrepBuffered {
+    pub fn read_match(
+        &self,
+        mat: &mut Match,
+    ) -> io::Result<bool> {
+        let buf = try!(self.buf.fill_buf());
+        if buf.is_empty() {
+            return Ok(false);
+        }
+        Ok(false)
+    }
+}

src/main.rs

@@ -1,6 +1,7 @@
 #![allow(dead_code, unused_variables)]
 
 extern crate docopt;
+extern crate grep;
 extern crate memchr;
 extern crate memmap;
 extern crate regex;
@@ -15,19 +16,13 @@ Options:
 ";
 
 use std::error::Error;
-use std::io::{self, BufRead, Write};
+use std::io::{self, Write};
 use std::process;
 use std::result;
 
 use docopt::Docopt;
-use regex::bytes::Regex;
 
-use literals::LiteralSets;
-use search::{LineSearcher, LineSearcherBuilder};
-
-mod literals;
-mod nonl;
-mod search;
+use grep::{Grep, GrepBuilder};
 
 pub type Result<T> = result::Result<T, Box<Error + Send + Sync>>;
 
@@ -53,36 +48,20 @@ fn main() {
 
 fn run(args: &Args) -> Result<u64> {
     if args.arg_file.is_empty() {
-        let expr = try!(parse(&args.arg_pattern));
-        let literals = LiteralSets::create(&expr);
-        let re = Regex::new(&expr.to_string()).unwrap();
-        let _stdin = io::stdin();
-        let stdin = _stdin.lock();
-        run_by_line(args, &re, stdin)
+        unimplemented!()
     } else {
         let searcher =
-            try!(LineSearcherBuilder::new(&args.arg_pattern).create());
-        if args.flag_count {
-            run_mmap_count_only(args, &searcher)
-        } else {
-            run_mmap(args, &searcher)
-        }
+            try!(GrepBuilder::new(&args.arg_pattern).create());
+        run_mmap(args, &searcher)
     }
 }
 
-#[inline(never)]
-fn run_mmap(args: &Args, searcher: &LineSearcher) -> Result<u64> {
-    use memmap::{Mmap, Protection};
-
-    assert!(args.arg_file.len() == 1);
-    let mut wtr = io::BufWriter::new(io::stdout());
-    let mmap = try!(Mmap::open_path(&args.arg_file[0], Protection::Read));
-    let text = unsafe { mmap.as_slice() };
-
-    let mut count = 0;
-    for m in searcher.search(text) {
-        try!(wtr.write(&text[m.start..m.end]));
-        try!(wtr.write(b"\n"));
+fn run_mmap(args: &Args, searcher: &Grep) -> Result<u64> {
+    for m in searcher.iter(text) {
+        if !args.flag_count {
+            try!(wtr.write(&text[m.start()..m.end()]));
+            try!(wtr.write(b"\n"));
+        }
         count += 1;
     }
     Ok(count)
@@ -100,36 +79,3 @@ fn run_mmap_count_only(args: &Args, searcher: &LineSearcher) -> Result<u64> {
     try!(writeln!(wtr, "{}", count));
     Ok(count)
 }
-
-fn run_by_line<B: BufRead>(
-    args: &Args,
-    re: &Regex,
-    mut rdr: B,
-) -> Result<u64> {
-    let mut wtr = io::BufWriter::new(io::stdout());
-    let mut count = 0;
-    let mut nline = 0;
-    let mut line = vec![];
-    loop {
-        line.clear();
-        let n = try!(rdr.read_until(b'\n', &mut line));
-        if n == 0 {
-            break;
-        }
-        nline += 1;
-        if re.is_match(&line) {
-            count += 1;
-            try!(wtr.write(&line));
-        }
-    }
-    Ok(count)
-}
-
-fn parse(re: &str) -> Result<syntax::Expr> {
-    let expr =
-        try!(syntax::ExprBuilder::new()
-             .allow_bytes(true)
-             .unicode(false)
-             .parse(re));
-    Ok(try!(nonl::remove(expr)))
-}

src/nonl.rs

@@ -1,55 +0,0 @@
-use syntax::Expr;
-
-use Result;
-
-/// Returns a new expression that is guaranteed to never match `\n`.
-///
-/// If the expression contains a literal `\n`, then an error is returned.
-pub fn remove(expr: Expr) -> Result<Expr> {
-    use syntax::Expr::*;
-    Ok(match expr {
-        Literal { chars, casei } => {
-            if chars.iter().position(|&c| c == '\n').is_some() {
-                return Err(format!("Literal '\\n' are not allowed.").into());
-            }
-            Literal { chars: chars, casei: casei }
-        }
-        LiteralBytes { bytes, casei } => {
-            if bytes.iter().position(|&b| b == b'\n').is_some() {
-                return Err(format!("Literal '\\n' are not allowed.").into());
-            }
-            LiteralBytes { bytes: bytes, casei: casei }
-        }
-        AnyChar => AnyCharNoNL,
-        AnyByte => AnyByteNoNL,
-        Class(mut cls) => {
-            cls.remove('\n');
-            Class(cls)
-        }
-        ClassBytes(mut cls) => {
-            cls.remove(b'\n');
-            ClassBytes(cls)
-        }
-        Group { e, i, name } => {
-            Group {
-                e: Box::new(try!(remove(*e))),
-                i: i,
-                name: name,
-            }
-        }
-        Repeat { e, r, greedy } => {
-            Repeat {
-                e: Box::new(try!(remove(*e))),
-                r: r,
-                greedy: greedy,
-            }
-        }
-        Concat(exprs) => {
-            Concat(try!(exprs.into_iter().map(remove).collect()))
-        }
-        Alternate(exprs) => {
-            Alternate(try!(exprs.into_iter().map(remove).collect()))
-        }
-        e => e,
-    })
-}

src/search.rs

@@ -1,168 +0,0 @@
-use std::cmp;
-
-use memchr::{memchr, memrchr};
-use regex::bytes::Regex;
-use syntax;
-
-use literals::LiteralSets;
-use nonl;
-use Result;
-
-#[derive(Clone, Debug)]
-pub struct LineSearcher {
-    re: Regex,
-    required: Option<Regex>,
-    opts: Options,
-}
-
-#[derive(Clone, Debug)]
-pub struct LineSearcherBuilder {
-    pattern: String,
-    opts: Options,
-}
-
-#[derive(Clone, Debug, Default)]
-struct Options {
-    case_insensitive: bool,
-    lines: bool,
-    locations: bool,
-}
-
-impl LineSearcherBuilder {
-    pub fn new(pattern: &str) -> LineSearcherBuilder {
-        LineSearcherBuilder {
-            pattern: pattern.to_string(),
-            opts: Options::default(),
-        }
-    }
-
-    pub fn case_insensitive(mut self, yes: bool) -> LineSearcherBuilder {
-        self.opts.case_insensitive = yes;
-        self
-    }
-
-    pub fn line_numbers(mut self, yes: bool) -> LineSearcherBuilder {
-        self.opts.lines = yes;
-        self
-    }
-
-    pub fn locations(mut self, yes: bool) -> LineSearcherBuilder {
-        self.opts.locations = yes;
-        self
-    }
-
-    pub fn create(self) -> Result<LineSearcher> {
-        let expr = try!(parse(&self.pattern));
-        let literals = LiteralSets::create(&expr);
-        let pat =
-            if self.opts.case_insensitive {
-                format!("(?i){}", expr)
-            } else {
-                expr.to_string()
-            };
-        // We've already parsed the pattern, so we know it will compiled.
-        let re = Regex::new(&pat).unwrap();
-        Ok(LineSearcher {
-            re: re,
-            required: literals.to_matcher(),
-            opts: self.opts,
-        })
-    }
-}
-
-impl LineSearcher {
-    pub fn search<'b, 's>(&'s self, buf: &'b [u8]) -> Iter<'b, 's> {
-        Iter {
-            searcher: self,
-            buf: buf,
-            start: 0,
-            count: 0,
-        }
-    }
-}
-
-pub struct Match {
-    pub start: usize,
-    pub end: usize,
-    pub count: u64,
-    pub line: Option<usize>,
-    pub locations: Vec<(usize, usize)>,
-}
-
-pub struct Iter<'b, 's> {
-    searcher: &'s LineSearcher,
-    buf: &'b [u8],
-    start: usize,
-    count: u64,
-}
-
-impl<'b, 's> Iter<'b, 's> {
-    #[inline(always)] // reduces constant overhead
-    fn next_line_match(&mut self) -> Option<(usize, usize)> {
-        if let Some(ref req) = self.searcher.required {
-            while self.start < self.buf.len() {
-                let e = match req.shortest_match(&self.buf[self.start..]) {
-                    None => return None,
-                    Some(e) => self.start + e,
-                };
-                let (prevnl, nextnl) = self.find_line(e, e);
-                match self.searcher.re.shortest_match(&self.buf[prevnl..nextnl]) {
-                    None => {
-                        self.start = nextnl + 1;
-                        continue;
-                    }
-                    Some(_) => return Some((prevnl, nextnl)),
-                }
-            }
-            None
-        } else {
-            self.searcher.re
-                .shortest_match(&self.buf[self.start..])
-                .map(|e| self.find_line(self.start + e, self.start + e))
-        }
-    }
-
-    fn find_line(&self, s: usize, e: usize) -> (usize, usize) {
-        (self.find_line_start(s), self.find_line_end(e))
-    }
-
-    fn find_line_start(&self, pos: usize) -> usize {
-        memrchr(b'\n', &self.buf[0..pos]).map_or(0, |i| i + 1)
-    }
-
-    fn find_line_end(&self, pos: usize) -> usize {
-        memchr(b'\n', &self.buf[pos..]).map_or(self.buf.len(), |i| pos + i)
-    }
-}
-
-impl<'b, 's> Iterator for Iter<'b, 's> {
-    type Item = Match;
-
-    #[inline(always)] // reduces constant overhead
-    fn next(&mut self) -> Option<Match> {
-        match self.next_line_match() {
-            None => None,
-            Some((prevnl, nextnl)) => {
-                let count = self.count;
-                self.start = cmp::min(self.buf.len(), nextnl + 1);
-                self.count += 1;
-                Some(Match {
-                    start: prevnl,
-                    end: nextnl,
-                    count: count,
-                    line: None,
-                    locations: vec![],
-                })
-            }
-        }
-    }
-}
-
-fn parse(re: &str) -> Result<syntax::Expr> {
-    let expr =
-        try!(syntax::ExprBuilder::new()
-             .allow_bytes(true)
-             .unicode(false)
-             .parse(re));
-    Ok(try!(nonl::remove(expr)))
-}