repo: move all source code in crates directory

The top-level listing was just getting a bit too long for my taste. So
put all of the code in one directory and shrink the large top-level mess
to a small top-level mess.

NOTE: This commit only contains renames. The subsequent commit will
actually make ripgrep build again. We do it this way with the naive hope
that this will make it easier for git history to track the renames.
Sigh.

crates/core/path_printer.rs

@@ -0,0 +1,98 @@
+use std::io;
+use std::path::Path;
+
+use grep::printer::{ColorSpecs, PrinterPath};
+use termcolor::WriteColor;
+
+/// A configuration for describing how paths should be written.
+#[derive(Clone, Debug)]
+struct Config {
+    colors: ColorSpecs,
+    separator: Option<u8>,
+    terminator: u8,
+}
+
+impl Default for Config {
+    fn default() -> Config {
+        Config {
+            colors: ColorSpecs::default(),
+            separator: None,
+            terminator: b'\n',
+        }
+    }
+}
+
+/// A builder for constructing things to search over.
+#[derive(Clone, Debug)]
+pub struct PathPrinterBuilder {
+    config: Config,
+}
+
+impl PathPrinterBuilder {
+    /// Return a new subject builder with a default configuration.
+    pub fn new() -> PathPrinterBuilder {
+        PathPrinterBuilder { config: Config::default() }
+    }
+
+    /// Create a new path printer with the current configuration that writes
+    /// paths to the given writer.
+    pub fn build<W: WriteColor>(&self, wtr: W) -> PathPrinter<W> {
+        PathPrinter { config: self.config.clone(), wtr: wtr }
+    }
+
+    /// Set the color specification for this printer.
+    ///
+    /// Currently, only the `path` component of the given specification is
+    /// used.
+    pub fn color_specs(
+        &mut self,
+        specs: ColorSpecs,
+    ) -> &mut PathPrinterBuilder {
+        self.config.colors = specs;
+        self
+    }
+
+    /// A path separator.
+    ///
+    /// When provided, the path's default separator will be replaced with
+    /// the given separator.
+    ///
+    /// This is not set by default, and the system's default path separator
+    /// will be used.
+    pub fn separator(&mut self, sep: Option<u8>) -> &mut PathPrinterBuilder {
+        self.config.separator = sep;
+        self
+    }
+
+    /// A path terminator.
+    ///
+    /// When printing a path, it will be by terminated by the given byte.
+    ///
+    /// This is set to `\n` by default.
+    pub fn terminator(&mut self, terminator: u8) -> &mut PathPrinterBuilder {
+        self.config.terminator = terminator;
+        self
+    }
+}
+
+/// A printer for emitting paths to a writer, with optional color support.
+#[derive(Debug)]
+pub struct PathPrinter<W> {
+    config: Config,
+    wtr: W,
+}
+
+impl<W: WriteColor> PathPrinter<W> {
+    /// Write the given path to the underlying writer.
+    pub fn write_path(&mut self, path: &Path) -> io::Result<()> {
+        let ppath = PrinterPath::with_separator(path, self.config.separator);
+        if !self.wtr.supports_color() {
+            self.wtr.write_all(ppath.as_bytes())?;
+        } else {
+            self.wtr.set_color(self.config.colors.path())?;
+            self.wtr.write_all(ppath.as_bytes())?;
+            self.wtr.reset()?;
+        }
+        self.wtr.write_all(&[self.config.terminator])
+    }
+}