Refactor how coloring is done.

All in the name of appeasing Windows.

src/args.rs

@@ -9,11 +9,12 @@ use grep::{Grep, GrepBuilder};
 use log;
 use num_cpus;
 use regex;
+use term::Terminal;
 use walkdir::WalkDir;
 
 use gitignore::{Gitignore, GitignoreBuilder};
 use ignore::Ignore;
-use out::Out;
+use out::{Out, OutBuffer};
 use printer::Printer;
 use search::{InputBuffer, Searcher};
 use search_buffer::BufferSearcher;
@@ -438,8 +439,8 @@ impl Args {
 
     /// Create a new printer of individual search results that writes to the
     /// writer given.
-    pub fn printer<W: Send + io::Write>(&self, wtr: W) -> Printer<W> {
-        let mut p = Printer::new(wtr, self.color)
+    pub fn printer<W: Send + Terminal>(&self, wtr: W) -> Printer<W> {
+        let mut p = Printer::new(wtr)
             .column(self.column)
             .context_separator(self.context_separator.clone())
             .eol(self.eol)
@@ -454,8 +455,8 @@ impl Args {
 
     /// Create a new printer of search results for an entire file that writes
     /// to the writer given.
-    pub fn out<W: io::Write>(&self, wtr: W) -> Out<W> {
-        let mut out = Out::new(wtr);
+    pub fn out(&self) -> Out {
+        let mut out = Out::new(self.color);
         if self.heading && !self.count {
             out = out.file_separator(b"".to_vec());
         } else if self.before_context > 0 || self.after_context > 0 {
@@ -464,6 +465,11 @@ impl Args {
         out
     }
 
+    /// Create a new buffer for use with searching.
+    pub fn outbuf(&self) -> OutBuffer {
+        OutBuffer::new(self.color)
+    }
+
     /// Return the paths that should be searched.
     pub fn paths(&self) -> &[PathBuf] {
         &self.paths
@@ -472,7 +478,7 @@ impl Args {
     /// Create a new line based searcher whose configuration is taken from the
     /// command line. This searcher supports a dizzying array of features:
     /// inverted matching, line counting, context control and more.
-    pub fn searcher<'a, R: io::Read, W: Send + io::Write>(
+    pub fn searcher<'a, R: io::Read, W: Send + Terminal>(
         &self,
         inp: &'a mut InputBuffer,
         printer: &'a mut Printer<W>,
@@ -493,7 +499,7 @@ impl Args {
     /// Create a new line based searcher whose configuration is taken from the
     /// command line. This search operates on an entire file all once (which
     /// may have been memory mapped).
-    pub fn searcher_buffer<'a, W: Send + io::Write>(
+    pub fn searcher_buffer<'a, W: Send + Terminal>(
         &self,
         printer: &'a mut Printer<W>,
         grep: &'a Grep,

src/main.rs

@@ -39,7 +39,7 @@ use term::Terminal;
 use walkdir::DirEntry;
 
 use args::Args;
-use out::Out;
+use out::{NoColorTerminal, Out, OutBuffer};
 use printer::Printer;
 use search::InputBuffer;
 
@@ -90,7 +90,8 @@ fn run(args: Args) -> Result<u64> {
         return run_types(args);
     }
     let args = Arc::new(args);
-    let out = Arc::new(Mutex::new(args.out(io::stdout())));
+    let out = Arc::new(Mutex::new(args.out()));
+    let outbuf = args.outbuf();
     let mut workers = vec![];
 
     let mut workq = {
@@ -101,7 +102,7 @@ fn run(args: Args) -> Result<u64> {
                 out: out.clone(),
                 chan_work: stealer.clone(),
                 inpbuf: args.input_buffer(),
-                outbuf: Some(vec![]),
+                outbuf: Some(outbuf.clone()),
                 grep: args.grep(),
                 match_count: 0,
             };
@@ -129,7 +130,8 @@ fn run(args: Args) -> Result<u64> {
 }
 
 fn run_files(args: Args) -> Result<u64> {
-    let mut printer = args.printer(io::BufWriter::new(io::stdout()));
+    let term = NoColorTerminal::new(io::BufWriter::new(io::stdout()));
+    let mut printer = args.printer(term);
     let mut file_count = 0;
     for p in args.paths() {
         if p == Path::new("-") {
@@ -146,7 +148,8 @@ fn run_files(args: Args) -> Result<u64> {
 }
 
 fn run_types(args: Args) -> Result<u64> {
-    let mut printer = args.printer(io::BufWriter::new(io::stdout()));
+    let term = NoColorTerminal::new(io::BufWriter::new(io::stdout()));
+    let mut printer = args.printer(term);
     let mut ty_count = 0;
     for def in args.type_defs() {
         printer.type_def(def);
@@ -168,10 +171,10 @@ enum WorkReady {
 
 struct Worker {
     args: Arc<Args>,
-    out: Arc<Mutex<Out<io::Stdout>>>,
+    out: Arc<Mutex<Out>>,
     chan_work: Stealer<Work>,
     inpbuf: InputBuffer,
-    outbuf: Option<Vec<u8>>,
+    outbuf: Option<OutBuffer>,
     grep: Grep,
     match_count: u64,
 }
@@ -203,12 +206,12 @@ impl Worker {
                 let mut out = self.out.lock().unwrap();
                 out.write(&outbuf);
             }
-            self.outbuf = Some(outbuf.into_inner());
+            self.outbuf = Some(outbuf);
         }
         self.match_count
     }
 
-    fn do_work<W: Send + io::Write>(
+    fn do_work<W: Send + Terminal>(
         &mut self,
         printer: &mut Printer<W>,
         work: WorkReady,
@@ -241,7 +244,7 @@ impl Worker {
         }
     }
 
-    fn search<R: io::Read, W: Send + io::Write>(
+    fn search<R: io::Read, W: Send + Terminal>(
         &mut self,
         printer: &mut Printer<W>,
         path: &Path,
@@ -256,7 +259,7 @@ impl Worker {
         ).run().map_err(From::from)
     }
 
-    fn search_mmap<W: Send + io::Write>(
+    fn search_mmap<W: Send + Terminal>(
         &mut self,
         printer: &mut Printer<W>,
         path: &Path,

src/out.rs

@@ -1,10 +1,40 @@
 use std::io::{self, Write};
+use std::sync::Arc;
 
-use term::{StdoutTerminal, Terminal};
+use term::{self, Terminal};
+use term::color::Color;
+use term::terminfo::TermInfo;
 #[cfg(windows)]
 use term::WinConsole;
 
-use printer::Writer;
+use terminal::TerminfoTerminal;
+
+pub type StdoutTerminal = Box<Terminal<Output=io::BufWriter<io::Stdout>> + Send>;
+
+/// Gets a terminal that supports color if available.
+#[cfg(windows)]
+fn term_stdout(color: bool) -> StdoutTerminal {
+    let stdout = io::BufWriter::new(io::stdout());
+    WinConsole::new(stdout)
+        .ok()
+        .map(|t| Box::new(t))
+        .unwrap_or_else(|| {
+            let stdout = io::BufWriter::new(io::stdout());
+            Box::new(NoColorTerminal::new(stdout))
+        })
+}
+
+/// Gets a terminal that supports color if available.
+#[cfg(not(windows))]
+fn term_stdout(color: bool) -> StdoutTerminal {
+    let stdout = io::BufWriter::new(io::stdout());
+    if !color || TERMINFO.is_none() {
+        Box::new(NoColorTerminal::new(stdout))
+    } else {
+        let info = TERMINFO.clone().unwrap();
+        Box::new(TerminfoTerminal::new_with_terminfo(stdout, info))
+    }
+}
 
 /// Out controls the actual output of all search results for a particular file
 /// to the end user.
@@ -12,34 +42,17 @@ use printer::Writer;
 /// (The difference between Out and Printer is that a Printer works with
 /// individual search results where as Out works with search results for each
 /// file as a whole. For example, it knows when to print a file separator.)
-pub struct Out<W: io::Write> {
-    wtr: io::BufWriter<W>,
-    term: Option<Box<StdoutTerminal>>,
+pub struct Out {
+    term: StdoutTerminal,
     printed: bool,
     file_separator: Option<Vec<u8>>,
 }
 
-/// This is like term::stdout, but on Windows always uses WinConsole instead
-/// of trying for a TerminfoTerminal. This may be a mistake.
-#[cfg(windows)]
-fn term_stdout() -> Option<Box<StdoutTerminal>> {
-    WinConsole::new(io::stdout())
-        .ok()
-        .map(|t| Box::new(t) as Box<StdoutTerminal>)
-}
-
-#[cfg(not(windows))]
-fn term_stdout() -> Option<Box<StdoutTerminal>> {
-    // We never use this crap on *nix.
-    None
-}
-
-impl<W: io::Write> Out<W> {
+impl Out {
     /// Create a new Out that writes to the wtr given.
-    pub fn new(wtr: W) -> Out<W> {
+    pub fn new(color: bool) -> Out {
         Out {
-            wtr: io::BufWriter::new(wtr),
-            term: term_stdout(),
+            term: term_stdout(color),
             printed: false,
             file_separator: None,
         }
@@ -49,39 +62,422 @@ impl<W: io::Write> Out<W> {
     /// By default, no separator is printed.
     ///
     /// If sep is empty, then no file separator is printed.
-    pub fn file_separator(mut self, sep: Vec<u8>) -> Out<W> {
+    pub fn file_separator(mut self, sep: Vec<u8>) -> Out {
         self.file_separator = Some(sep);
         self
     }
 
     /// Write the search results of a single file to the underlying wtr and
     /// flush wtr.
-    pub fn write(&mut self, buf: &Writer<Vec<u8>>) {
+    pub fn write(&mut self, buf: &OutBuffer) {
         if let Some(ref sep) = self.file_separator {
             if self.printed {
-                let _ = self.wtr.write_all(sep);
-                let _ = self.wtr.write_all(b"\n");
+                let _ = self.term.write_all(sep);
+                let _ = self.term.write_all(b"\n");
             }
         }
         match *buf {
-            Writer::Colored(ref tt) => {
-                let _ = self.wtr.write_all(tt.get_ref());
+            OutBuffer::Colored(ref tt) => {
+                let _ = self.term.write_all(tt.get_ref());
             }
-            Writer::Windows(ref w) => {
-                match self.term {
-                    None => {
-                        let _ = self.wtr.write_all(w.get_ref());
-                    }
-                    Some(ref mut stdout) => {
-                        w.print_stdout(stdout);
-                    }
-                }
+            OutBuffer::Windows(ref w) => {
+                w.print_stdout(&mut self.term);
             }
-            Writer::NoColor(ref buf) => {
-                let _ = self.wtr.write_all(buf);
+            OutBuffer::NoColor(ref buf) => {
+                let _ = self.term.write_all(buf);
             }
         }
-        let _ = self.wtr.flush();
+        let _ = self.term.flush();
         self.printed = true;
     }
 }
+
+/// OutBuffer corresponds to the final output buffer for search results. All
+/// search results are written to a buffer and then a buffer is flushed to
+/// stdout only after the full search has completed.
+#[derive(Clone, Debug)]
+pub enum OutBuffer {
+    Colored(TerminfoTerminal<Vec<u8>>),
+    Windows(WindowsBuffer),
+    NoColor(Vec<u8>),
+}
+
+#[derive(Clone, Debug)]
+pub struct WindowsBuffer {
+    buf: Vec<u8>,
+    pos: usize,
+    colors: Vec<WindowsColor>,
+}
+
+#[derive(Clone, Debug)]
+pub struct WindowsColor {
+    pos: usize,
+    opt: WindowsOption,
+}
+
+#[derive(Clone, Debug)]
+pub enum WindowsOption {
+    Foreground(Color),
+    Background(Color),
+    Reset,
+}
+
+lazy_static! {
+    static ref TERMINFO: Option<Arc<TermInfo>> = {
+        match TermInfo::from_env() {
+            Ok(info) => Some(Arc::new(info)),
+            Err(err) => {
+                debug!("error loading terminfo for coloring: {}", err);
+                None
+            }
+        }
+    };
+}
+
+impl OutBuffer {
+    /// Create a new output buffer.
+    ///
+    /// When color is true, the buffer will attempt to support coloring.
+    pub fn new(color: bool) -> OutBuffer {
+        // If we want color, build a TerminfoTerminal and see if the current
+        // environment supports coloring. If not, bail with NoColor. To avoid
+        // losing our writer (ownership), do this the long way.
+        if !color {
+            return OutBuffer::NoColor(vec![]);
+        }
+        if cfg!(windows) {
+            return OutBuffer::Windows(WindowsBuffer {
+                buf: vec![],
+                pos: 0,
+                colors: vec![]
+            });
+        }
+        if TERMINFO.is_none() {
+            return OutBuffer::NoColor(vec![]);
+        }
+        let info = TERMINFO.clone().unwrap();
+        let tt = TerminfoTerminal::new_with_terminfo(vec![], info);
+        if !tt.supports_color() {
+            debug!("environment doesn't support coloring");
+            return OutBuffer::NoColor(tt.into_inner());
+        }
+        OutBuffer::Colored(tt)
+    }
+
+    /// Clear the give buffer of all search results such that it is reusable
+    /// in another search.
+    pub fn clear(&mut self) {
+        match *self {
+            OutBuffer::Colored(ref mut tt) => {
+                tt.get_mut().clear();
+            }
+            OutBuffer::Windows(ref mut win) => {
+                win.buf.clear();
+                win.colors.clear();
+                win.pos = 0;
+            }
+            OutBuffer::NoColor(ref mut buf) => {
+                buf.clear();
+            }
+        }
+    }
+
+    fn map_result<F, G>(
+        &mut self,
+        mut f: F,
+        mut g: G,
+    ) -> term::Result<()>
+    where F: FnMut(&mut TerminfoTerminal<Vec<u8>>) -> term::Result<()>,
+          G: FnMut(&mut WindowsBuffer) -> term::Result<()> {
+        match *self {
+            OutBuffer::Colored(ref mut w) => f(w),
+            OutBuffer::Windows(ref mut w) => g(w),
+            OutBuffer::NoColor(_) => Err(term::Error::NotSupported),
+        }
+    }
+
+    fn map_bool<F, G>(
+        &self,
+        mut f: F,
+        mut g: G,
+    ) -> bool
+    where F: FnMut(&TerminfoTerminal<Vec<u8>>) -> bool,
+          G: FnMut(&WindowsBuffer) -> bool {
+        match *self {
+            OutBuffer::Colored(ref w) => f(w),
+            OutBuffer::Windows(ref w) => g(w),
+            OutBuffer::NoColor(_) => false,
+        }
+    }
+}
+
+impl io::Write for OutBuffer {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        match *self {
+            OutBuffer::Colored(ref mut w) => w.write(buf),
+            OutBuffer::Windows(ref mut w) => w.write(buf),
+            OutBuffer::NoColor(ref mut w) => w.write(buf),
+        }
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+impl term::Terminal for OutBuffer {
+    type Output = Vec<u8>;
+
+    fn fg(&mut self, fg: term::color::Color) -> term::Result<()> {
+        self.map_result(|w| w.fg(fg), |w| w.fg(fg))
+    }
+
+    fn bg(&mut self, bg: term::color::Color) -> term::Result<()> {
+        self.map_result(|w| w.bg(bg), |w| w.bg(bg))
+    }
+
+    fn attr(&mut self, attr: term::Attr) -> term::Result<()> {
+        self.map_result(|w| w.attr(attr), |w| w.attr(attr))
+    }
+
+    fn supports_attr(&self, attr: term::Attr) -> bool {
+        self.map_bool(|w| w.supports_attr(attr), |w| w.supports_attr(attr))
+    }
+
+    fn reset(&mut self) -> term::Result<()> {
+        self.map_result(|w| w.reset(), |w| w.reset())
+    }
+
+    fn supports_reset(&self) -> bool {
+        self.map_bool(|w| w.supports_reset(), |w| w.supports_reset())
+    }
+
+    fn supports_color(&self) -> bool {
+        self.map_bool(|w| w.supports_color(), |w| w.supports_color())
+    }
+
+    fn cursor_up(&mut self) -> term::Result<()> {
+        self.map_result(|w| w.cursor_up(), |w| w.cursor_up())
+    }
+
+    fn delete_line(&mut self) -> term::Result<()> {
+        self.map_result(|w| w.delete_line(), |w| w.delete_line())
+    }
+
+    fn carriage_return(&mut self) -> term::Result<()> {
+        self.map_result(|w| w.carriage_return(), |w| w.carriage_return())
+    }
+
+    fn get_ref(&self) -> &Vec<u8> {
+        match *self {
+            OutBuffer::Colored(ref w) => w.get_ref(),
+            OutBuffer::Windows(ref w) => w.get_ref(),
+            OutBuffer::NoColor(ref w) => w,
+        }
+    }
+
+    fn get_mut(&mut self) -> &mut Vec<u8> {
+        match *self {
+            OutBuffer::Colored(ref mut w) => w.get_mut(),
+            OutBuffer::Windows(ref mut w) => w.get_mut(),
+            OutBuffer::NoColor(ref mut w) => w,
+        }
+    }
+
+    fn into_inner(self) -> Vec<u8> {
+        match self {
+            OutBuffer::Colored(w) => w.into_inner(),
+            OutBuffer::Windows(w) => w.into_inner(),
+            OutBuffer::NoColor(w) => w,
+        }
+    }
+}
+
+impl WindowsBuffer {
+    fn push(&mut self, opt: WindowsOption) {
+        let pos = self.pos;
+        self.colors.push(WindowsColor { pos: pos, opt: opt });
+    }
+}
+
+impl WindowsBuffer {
+    /// Print the contents to the given terminal.
+    pub fn print_stdout(&self, tt: &mut StdoutTerminal) {
+        if !tt.supports_color() {
+            let _ = tt.write_all(&self.buf);
+            let _ = tt.flush();
+            return;
+        }
+        let mut last = 0;
+        for col in &self.colors {
+            let _ = tt.write_all(&self.buf[last..col.pos]);
+            match col.opt {
+                WindowsOption::Foreground(c) => {
+                    let _ = tt.fg(c);
+                }
+                WindowsOption::Background(c) => {
+                    let _ = tt.bg(c);
+                }
+                WindowsOption::Reset => {
+                    let _ = tt.reset();
+                }
+            }
+            last = col.pos;
+        }
+        let _ = tt.write_all(&self.buf[last..]);
+        let _ = tt.flush();
+    }
+}
+
+impl io::Write for WindowsBuffer {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        let n = try!(self.buf.write(buf));
+        self.pos += n;
+        Ok(n)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+impl term::Terminal for WindowsBuffer {
+    type Output = Vec<u8>;
+
+    fn fg(&mut self, fg: term::color::Color) -> term::Result<()> {
+        self.push(WindowsOption::Foreground(fg));
+        Ok(())
+    }
+
+    fn bg(&mut self, bg: term::color::Color) -> term::Result<()> {
+        self.push(WindowsOption::Background(bg));
+        Ok(())
+    }
+
+    fn attr(&mut self, attr: term::Attr) -> term::Result<()> {
+        Err(term::Error::NotSupported)
+    }
+
+    fn supports_attr(&self, attr: term::Attr) -> bool {
+        false
+    }
+
+    fn reset(&mut self) -> term::Result<()> {
+        self.push(WindowsOption::Reset);
+        Ok(())
+    }
+
+    fn supports_reset(&self) -> bool {
+        true
+    }
+
+    fn supports_color(&self) -> bool {
+        true
+    }
+
+    fn cursor_up(&mut self) -> term::Result<()> {
+        Err(term::Error::NotSupported)
+    }
+
+    fn delete_line(&mut self) -> term::Result<()> {
+        Err(term::Error::NotSupported)
+    }
+
+    fn carriage_return(&mut self) -> term::Result<()> {
+        Err(term::Error::NotSupported)
+    }
+
+    fn get_ref(&self) -> &Vec<u8> {
+        &self.buf
+    }
+
+    fn get_mut(&mut self) -> &mut Vec<u8> {
+        &mut self.buf
+    }
+
+    fn into_inner(self) -> Vec<u8> {
+        self.buf
+    }
+}
+
+/// NoColorTerminal implements Terminal, but supports no coloring.
+///
+/// Its useful when an API requires a Terminal, but coloring isn't needed.
+pub struct NoColorTerminal<W> {
+    wtr: W,
+}
+
+impl<W: Send + io::Write> NoColorTerminal<W> {
+    /// Wrap the given writer in a Terminal interface.
+    pub fn new(wtr: W) -> NoColorTerminal<W> {
+        NoColorTerminal {
+            wtr: wtr,
+        }
+    }
+}
+
+impl<W: Send + io::Write> io::Write for NoColorTerminal<W> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.wtr.write(buf)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        self.wtr.flush()
+    }
+}
+
+impl<W: Send + io::Write> term::Terminal for NoColorTerminal<W> {
+    type Output = W;
+
+    fn fg(&mut self, fg: term::color::Color) -> term::Result<()> {
+        Err(term::Error::NotSupported)
+    }
+
+    fn bg(&mut self, bg: term::color::Color) -> term::Result<()> {
+        Err(term::Error::NotSupported)
+    }
+
+    fn attr(&mut self, attr: term::Attr) -> term::Result<()> {
+        Err(term::Error::NotSupported)
+    }
+
+    fn supports_attr(&self, attr: term::Attr) -> bool {
+        false
+    }
+
+    fn reset(&mut self) -> term::Result<()> {
+        Err(term::Error::NotSupported)
+    }
+
+    fn supports_reset(&self) -> bool {
+        false
+    }
+
+    fn supports_color(&self) -> bool {
+        false
+    }
+
+    fn cursor_up(&mut self) -> term::Result<()> {
+        Err(term::Error::NotSupported)
+    }
+
+    fn delete_line(&mut self) -> term::Result<()> {
+        Err(term::Error::NotSupported)
+    }
+
+    fn carriage_return(&mut self) -> term::Result<()> {
+        Err(term::Error::NotSupported)
+    }
+
+    fn get_ref(&self) -> &W {
+        &self.wtr
+    }
+
+    fn get_mut(&mut self) -> &mut W {
+        &mut self.wtr
+    }
+
+    fn into_inner(self) -> W {
+        self.wtr
+    }
+}

src/printer.rs

@@ -1,17 +1,11 @@
-use std::io::{self, Write};
 use std::path::Path;
-use std::sync::Arc;
 
 use regex::bytes::Regex;
-use term::{self, StdoutTerminal, Terminal};
-use term::color::*;
-use term::terminfo::TermInfo;
+use term::{Attr, Terminal};
+use term::color;
 
-use terminal::TerminfoTerminal;
 use types::FileTypeDef;
 
-use self::Writer::*;
-
 /// Printer encapsulates all output logic for searching.
 ///
 /// Note that we currently ignore all write errors. It's probably worthwhile
@@ -19,7 +13,7 @@ use self::Writer::*;
 /// writes to memory, neither of which commonly fail.
 pub struct Printer<W> {
     /// The underlying writer.
-    wtr: Writer<W>,
+    wtr: W,
     /// Whether anything has been printed to wtr yet.
     has_printed: bool,
     /// Whether to show column numbers for the first match or not.
@@ -42,13 +36,11 @@ pub struct Printer<W> {
     with_filename: bool,
 }
 
-impl<W: Send + io::Write> Printer<W> {
+impl<W: Send + Terminal> Printer<W> {
     /// Create a new printer that writes to wtr.
-    ///
-    /// `color` should be true if the printer should try to use coloring.
-    pub fn new(wtr: W, color: bool) -> Printer<W> {
+    pub fn new(wtr: W) -> Printer<W> {
         Printer {
-            wtr: Writer::new(wtr, color),
+            wtr: wtr,
             has_printed: false,
             column: false,
             context_separator: "--".to_string().into_bytes(),
@@ -115,7 +107,7 @@ impl<W: Send + io::Write> Printer<W> {
     }
 
     /// Flushes the underlying writer and returns it.
-    pub fn into_inner(mut self) -> Writer<W> {
+    pub fn into_inner(mut self) -> W {
         let _ = self.wtr.flush();
         self.wtr
     }
@@ -201,15 +193,15 @@ impl<W: Send + io::Write> Printer<W> {
     }
 
     pub fn write_match(&mut self, re: &Regex, buf: &[u8]) {
-        if !self.wtr.is_color() {
+        if !self.wtr.supports_color() {
             self.write(buf);
             return;
         }
         let mut last_written = 0;
         for (s, e) in re.find_iter(buf) {
             self.write(&buf[last_written..s]);
-            let _ = self.wtr.fg(BRIGHT_RED);
-            let _ = self.wtr.attr(term::Attr::Bold);
+            let _ = self.wtr.fg(color::BRIGHT_RED);
+            let _ = self.wtr.attr(Attr::Bold);
             self.write(&buf[s..e]);
             let _ = self.wtr.reset();
             last_written = e;
@@ -241,24 +233,24 @@ impl<W: Send + io::Write> Printer<W> {
     }
 
     fn write_heading<P: AsRef<Path>>(&mut self, path: P) {
-        if self.wtr.is_color() {
-            let _ = self.wtr.fg(BRIGHT_GREEN);
-            let _ = self.wtr.attr(term::Attr::Bold);
+        if self.wtr.supports_color() {
+            let _ = self.wtr.fg(color::BRIGHT_GREEN);
+            let _ = self.wtr.attr(Attr::Bold);
         }
         self.write(path.as_ref().to_string_lossy().as_bytes());
         self.write_eol();
-        if self.wtr.is_color() {
+        if self.wtr.supports_color() {
             let _ = self.wtr.reset();
         }
     }
 
     fn line_number(&mut self, n: u64, sep: u8) {
-        if self.wtr.is_color() {
-            let _ = self.wtr.fg(BRIGHT_BLUE);
-            let _ = self.wtr.attr(term::Attr::Bold);
+        if self.wtr.supports_color() {
+            let _ = self.wtr.fg(color::BRIGHT_BLUE);
+            let _ = self.wtr.attr(Attr::Bold);
         }
         self.write(n.to_string().as_bytes());
-        if self.wtr.is_color() {
+        if self.wtr.supports_color() {
             let _ = self.wtr.reset();
         }
         self.write(&[sep]);
@@ -277,289 +269,3 @@ impl<W: Send + io::Write> Printer<W> {
         self.write(&[eol]);
     }
 }
-
-/// Writer corresponds to the final output buffer for search results. All
-/// search results are written to a Writer and then a Writer is flushed to
-/// stdout only after the full search has completed.
-pub enum Writer<W> {
-    Colored(TerminfoTerminal<W>),
-    Windows(WindowsWriter<W>),
-    NoColor(W),
-}
-
-pub struct WindowsWriter<W> {
-    wtr: W,
-    pos: usize,
-    colors: Vec<WindowsColor>,
-}
-
-pub struct WindowsColor {
-    pos: usize,
-    opt: WindowsOption,
-}
-
-pub enum WindowsOption {
-    Foreground(Color),
-    Background(Color),
-    Reset,
-}
-
-lazy_static! {
-    static ref TERMINFO: Option<Arc<TermInfo>> = {
-        match term::terminfo::TermInfo::from_env() {
-            Ok(info) => Some(Arc::new(info)),
-            Err(err) => {
-                debug!("error loading terminfo for coloring: {}", err);
-                None
-            }
-        }
-    };
-}
-
-impl<W: Send + io::Write> Writer<W> {
-    fn new(wtr: W, color: bool) -> Writer<W> {
-        // If we want color, build a TerminfoTerminal and see if the current
-        // environment supports coloring. If not, bail with NoColor. To avoid
-        // losing our writer (ownership), do this the long way.
-        if !color {
-            return NoColor(wtr);
-        }
-        if cfg!(windows) {
-            return Windows(WindowsWriter { wtr: wtr, pos: 0, colors: vec![] });
-        }
-        if TERMINFO.is_none() {
-            return NoColor(wtr);
-        }
-        let info = TERMINFO.clone().unwrap();
-        let tt = TerminfoTerminal::new_with_terminfo(wtr, info);
-        if !tt.supports_color() {
-            debug!("environment doesn't support coloring");
-            return NoColor(tt.into_inner());
-        }
-        Colored(tt)
-    }
-
-    fn is_color(&self) -> bool {
-        match *self {
-            Colored(_) => true,
-            Windows(_) => true,
-            NoColor(_) => false,
-        }
-    }
-
-    fn map_result<F, G>(
-        &mut self,
-        mut f: F,
-        mut g: G,
-    ) -> term::Result<()>
-    where F: FnMut(&mut TerminfoTerminal<W>) -> term::Result<()>,
-          G: FnMut(&mut WindowsWriter<W>) -> term::Result<()> {
-        match *self {
-            Colored(ref mut w) => f(w),
-            Windows(ref mut w) => g(w),
-            NoColor(_) => Err(term::Error::NotSupported),
-        }
-    }
-
-    fn map_bool<F, G>(
-        &self,
-        mut f: F,
-        mut g: G,
-    ) -> bool
-    where F: FnMut(&TerminfoTerminal<W>) -> bool,
-          G: FnMut(&WindowsWriter<W>) -> bool {
-        match *self {
-            Colored(ref w) => f(w),
-            Windows(ref w) => g(w),
-            NoColor(_) => false,
-        }
-    }
-}
-
-impl<W: Send + io::Write> io::Write for Writer<W> {
-    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        match *self {
-            Colored(ref mut w) => w.write(buf),
-            Windows(ref mut w) => w.write(buf),
-            NoColor(ref mut w) => w.write(buf),
-        }
-    }
-
-    fn flush(&mut self) -> io::Result<()> {
-        match *self {
-            Colored(ref mut w) => w.flush(),
-            Windows(ref mut w) => w.flush(),
-            NoColor(ref mut w) => w.flush(),
-        }
-    }
-}
-
-impl<W: Send + io::Write> term::Terminal for Writer<W> {
-    type Output = W;
-
-    fn fg(&mut self, fg: term::color::Color) -> term::Result<()> {
-        self.map_result(|w| w.fg(fg), |w| w.fg(fg))
-    }
-
-    fn bg(&mut self, bg: term::color::Color) -> term::Result<()> {
-        self.map_result(|w| w.bg(bg), |w| w.bg(bg))
-    }
-
-    fn attr(&mut self, attr: term::Attr) -> term::Result<()> {
-        self.map_result(|w| w.attr(attr), |w| w.attr(attr))
-    }
-
-    fn supports_attr(&self, attr: term::Attr) -> bool {
-        self.map_bool(|w| w.supports_attr(attr), |w| w.supports_attr(attr))
-    }
-
-    fn reset(&mut self) -> term::Result<()> {
-        self.map_result(|w| w.reset(), |w| w.reset())
-    }
-
-    fn supports_reset(&self) -> bool {
-        self.map_bool(|w| w.supports_reset(), |w| w.supports_reset())
-    }
-
-    fn supports_color(&self) -> bool {
-        self.map_bool(|w| w.supports_color(), |w| w.supports_color())
-    }
-
-    fn cursor_up(&mut self) -> term::Result<()> {
-        self.map_result(|w| w.cursor_up(), |w| w.cursor_up())
-    }
-
-    fn delete_line(&mut self) -> term::Result<()> {
-        self.map_result(|w| w.delete_line(), |w| w.delete_line())
-    }
-
-    fn carriage_return(&mut self) -> term::Result<()> {
-        self.map_result(|w| w.carriage_return(), |w| w.carriage_return())
-    }
-
-    fn get_ref(&self) -> &W {
-        match *self {
-            Colored(ref w) => w.get_ref(),
-            Windows(ref w) => w.get_ref(),
-            NoColor(ref w) => w,
-        }
-    }
-
-    fn get_mut(&mut self) -> &mut W {
-        match *self {
-            Colored(ref mut w) => w.get_mut(),
-            Windows(ref mut w) => w.get_mut(),
-            NoColor(ref mut w) => w,
-        }
-    }
-
-    fn into_inner(self) -> W {
-        match self {
-            Colored(w) => w.into_inner(),
-            Windows(w) => w.into_inner(),
-            NoColor(w) => w,
-        }
-    }
-}
-
-impl<W: Send + io::Write> WindowsWriter<W> {
-    fn push(&mut self, opt: WindowsOption) {
-        let pos = self.pos;
-        self.colors.push(WindowsColor { pos: pos, opt: opt });
-    }
-}
-
-impl WindowsWriter<Vec<u8>> {
-    /// Print the contents to the given terminal.
-    pub fn print_stdout(&self, tt: &mut Box<StdoutTerminal>) {
-        let mut last = 0;
-        for col in &self.colors {
-            let _ = tt.write_all(&self.wtr[last..col.pos]);
-            match col.opt {
-                WindowsOption::Foreground(c) => {
-                    let _ = tt.fg(c);
-                }
-                WindowsOption::Background(c) => {
-                    let _ = tt.bg(c);
-                }
-                WindowsOption::Reset => {
-                    let _ = tt.reset();
-                }
-            }
-            last = col.pos;
-        }
-        let _ = tt.write_all(&self.wtr[last..]);
-        let _ = tt.flush();
-    }
-}
-
-impl<W: Send + io::Write> io::Write for WindowsWriter<W> {
-    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        let n = try!(self.wtr.write(buf));
-        self.pos += n;
-        Ok(n)
-    }
-
-    fn flush(&mut self) -> io::Result<()> {
-        self.wtr.flush()
-    }
-}
-
-impl<W: Send + io::Write> term::Terminal for WindowsWriter<W> {
-    type Output = W;
-
-    fn fg(&mut self, fg: term::color::Color) -> term::Result<()> {
-        self.push(WindowsOption::Foreground(fg));
-        Ok(())
-    }
-
-    fn bg(&mut self, bg: term::color::Color) -> term::Result<()> {
-        self.push(WindowsOption::Background(bg));
-        Ok(())
-    }
-
-    fn attr(&mut self, attr: term::Attr) -> term::Result<()> {
-        Err(term::Error::NotSupported)
-    }
-
-    fn supports_attr(&self, attr: term::Attr) -> bool {
-        false
-    }
-
-    fn reset(&mut self) -> term::Result<()> {
-        self.push(WindowsOption::Reset);
-        Ok(())
-    }
-
-    fn supports_reset(&self) -> bool {
-        true
-    }
-
-    fn supports_color(&self) -> bool {
-        true
-    }
-
-    fn cursor_up(&mut self) -> term::Result<()> {
-        Err(term::Error::NotSupported)
-    }
-
-    fn delete_line(&mut self) -> term::Result<()> {
-        Err(term::Error::NotSupported)
-    }
-
-    fn carriage_return(&mut self) -> term::Result<()> {
-        Err(term::Error::NotSupported)
-    }
-
-    fn get_ref(&self) -> &W {
-        &self.wtr
-    }
-
-    fn get_mut(&mut self) -> &mut W {
-        &mut self.wtr
-    }
-
-    fn into_inner(self) -> W {
-        self.wtr
-    }
-}

src/search.rs

@@ -11,6 +11,7 @@ use std::path::{Path, PathBuf};
 
 use grep::{Grep, Match};
 use memchr::{memchr, memrchr};
+use term::Terminal;
 
 use printer::Printer;
 
@@ -98,7 +99,7 @@ impl Default for Options {
     }
 }
 
-impl<'a, R: io::Read, W: Send + io::Write> Searcher<'a, R, W> {
+impl<'a, R: io::Read, W: Send + Terminal> Searcher<'a, R, W> {
     /// Create a new searcher.
     ///
     /// `inp` is a reusable input buffer that is used as scratch space by this
@@ -689,6 +690,7 @@ mod tests {
     use grep::{Grep, GrepBuilder};
     use term::Terminal;
 
+    use out::OutBuffer;
     use printer::Printer;
 
     use super::{InputBuffer, Searcher, start_of_previous_lines};
@@ -731,7 +733,7 @@ fn main() {
         &Path::new("/baz.rs")
     }
 
-    type TestSearcher<'a> = Searcher<'a, io::Cursor<Vec<u8>>, Vec<u8>>;
+    type TestSearcher<'a> = Searcher<'a, io::Cursor<Vec<u8>>, OutBuffer>;
 
     fn search_smallcap<F: FnMut(TestSearcher) -> TestSearcher>(
         pat: &str,
@@ -739,7 +741,8 @@ fn main() {
         mut map: F,
     ) -> (u64, String) {
         let mut inp = InputBuffer::with_capacity(1);
-        let mut pp = Printer::new(vec![], false).with_filename(true);
+        let outbuf = OutBuffer::NoColor(vec![]);
+        let mut pp = Printer::new(outbuf).with_filename(true);
         let grep = GrepBuilder::new(pat).build().unwrap();
         let count = {
             let searcher = Searcher::new(
@@ -755,7 +758,8 @@ fn main() {
         mut map: F,
     ) -> (u64, String) {
         let mut inp = InputBuffer::with_capacity(4096);
-        let mut pp = Printer::new(vec![], false).with_filename(true);
+        let outbuf = OutBuffer::NoColor(vec![]);
+        let mut pp = Printer::new(outbuf).with_filename(true);
         let grep = GrepBuilder::new(pat).build().unwrap();
         let count = {
             let searcher = Searcher::new(

src/search_buffer.rs

@@ -1,8 +1,8 @@
 use std::cmp;
-use std::io;
 use std::path::Path;
 
 use grep::Grep;
+use term::Terminal;
 
 use printer::Printer;
 use search::{IterLines, Options, count_lines, is_binary};
@@ -18,7 +18,7 @@ pub struct BufferSearcher<'a, W: 'a> {
     last_line: usize,
 }
 
-impl<'a, W: Send + io::Write> BufferSearcher<'a, W> {
+impl<'a, W: Send + Terminal> BufferSearcher<'a, W> {
     pub fn new(
         printer: &'a mut Printer<W>,
         grep: &'a Grep,
@@ -146,6 +146,7 @@ mod tests {
     use grep::{Grep, GrepBuilder};
     use term::Terminal;
 
+    use out::OutBuffer;
     use printer::Printer;
 
     use super::BufferSearcher;
@@ -184,14 +185,15 @@ fn main() {
         &Path::new("/baz.rs")
     }
 
-    type TestSearcher<'a> = BufferSearcher<'a, Vec<u8>>;
+    type TestSearcher<'a> = BufferSearcher<'a, OutBuffer>;
 
     fn search<F: FnMut(TestSearcher) -> TestSearcher>(
         pat: &str,
         haystack: &str,
         mut map: F,
     ) -> (u64, String) {
-        let mut pp = Printer::new(vec![], false).with_filename(true);
+        let outbuf = OutBuffer::NoColor(vec![]);
+        let mut pp = Printer::new(outbuf).with_filename(true);
         let grep = GrepBuilder::new(pat).build().unwrap();
         let count = {
             let searcher = BufferSearcher::new(