Add ability to colorize column numbers.

Fixes #377

doc/rg.1

@@ -181,7 +181,7 @@ Styles are limited to nobold, bold, nointense or intense.
 .RS
 .PP
 The format of the flag is {type}:{attribute}:{value}.
-{type} should be one of path, line or match.
+{type} should be one of path, line, column or match.
 {attribute} can be fg, bg or style.
 Value is either a color (for fg and bg) or a text style.
 A special format, {type}:none, will clear all color settings for {type}.

doc/rg.1.md

@@ -123,9 +123,9 @@ Project home page: https://github.com/BurntSushi/ripgrep
   black. Styles are limited to nobold, bold, nointense or intense.
 
     The format of the flag is {type}:{attribute}:{value}. {type} should be one
-    of path, line or match. {attribute} can be fg, bg or style. Value is either
-    a color (for fg and bg) or a text style. A special format, {type}:none,
-    will clear all color settings for {type}.
+    of path, line, column or match. {attribute} can be fg, bg or style. Value
+    is either a color (for fg and bg) or a text style. A special format,
+    {type}:none, will clear all color settings for {type}.
 
     For example, the following command will change the match color to magenta
     and the background color for line numbers to yellow:

src/app.rs

@@ -235,12 +235,12 @@ lazy_static! {
               red, blue, green, cyan, magenta, yellow, white and black. \
               Styles are limited to nobold, bold, nointense or intense.\n\n\
               The format of the flag is {type}:{attribute}:{value}. {type} \
-              should be one of path, line or match. {attribute} can be fg, bg \
-              or style. {value} is either a color (for fg and bg) or a text \
-              style. A special format, {type}:none, will clear all color \
-              settings for {type}.\n\nFor example, the following command will \
-              change the match color to magenta and the background color for \
-              line numbers to yellow:\n\n\
+              should be one of path, line, column or match. {attribute} can \
+              be fg, bg or style. {value} is either a color (for fg and bg) \
+              or a text style. A special format, {type}:none, will clear all \
+              color settings for {type}.\n\nFor example, the following \
+              command will change the match color to magenta and the \
+              background color for line numbers to yellow:\n\n\
               rg --colors 'match:fg:magenta' --colors 'line:bg:yellow' foo.");
         doc!(h, "encoding",
              "Specify the text encoding of files to search.",

src/printer.rs

@@ -428,7 +428,7 @@ impl<W: WriteColor> Printer<W> {
     }
 
     fn column_number(&mut self, n: u64, sep: u8) {
-        self.write(n.to_string().as_bytes());
+        self.write_colored(n.to_string().as_bytes(), |colors| colors.column());
         self.separator(&[sep]);
     }
 
@@ -495,7 +495,7 @@ impl fmt::Display for Error {
         match *self {
             Error::UnrecognizedOutType(ref name) => {
                 write!(f, "Unrecognized output type '{}'. Choose from: \
-                           path, line, match.", name)
+                           path, line, column, match.", name)
             }
             Error::UnrecognizedSpecType(ref name) => {
                 write!(f, "Unrecognized spec type '{}'. Choose from: \
@@ -509,9 +509,11 @@ impl fmt::Display for Error {
                            nobold, bold, nointense, intense.", name)
             }
             Error::InvalidFormat(ref original) => {
-                write!(f, "Invalid color speci format: '{}'. Valid format \
-                           is '(path|line|match):(fg|bg|style):(value)'.",
-                           original)
+                write!(
+                    f,
+                    "Invalid color speci format: '{}'. Valid format \
+                     is '(path|line|column|match):(fg|bg|style):(value)'.",
+                    original)
             }
         }
     }
@@ -528,6 +530,7 @@ impl From<ParseColorError> for Error {
 pub struct ColorSpecs {
     path: ColorSpec,
     line: ColorSpec,
+    column: ColorSpec,
     matched: ColorSpec,
 }
 
@@ -557,7 +560,7 @@ pub struct ColorSpecs {
 /// The format of a `Spec` is a triple: `{type}:{attribute}:{value}`. Each
 /// component is defined as follows:
 ///
-/// * `{type}` can be one of `path`, `line` or `match`.
+/// * `{type}` can be one of `path`, `line`, `column` or `match`.
 /// * `{attribute}` can be one of `fg`, `bg` or `style`. `{attribute}` may also
 ///   be the special value `none`, in which case, `{value}` can be omitted.
 /// * `{value}` is either a color name (for `fg`/`bg`) or a style instruction.
@@ -596,6 +599,7 @@ enum SpecValue {
 enum OutType {
     Path,
     Line,
+    Column,
     Match,
 }
 
@@ -626,6 +630,7 @@ impl ColorSpecs {
             match user_spec.ty {
                 OutType::Path => user_spec.merge_into(&mut specs.path),
                 OutType::Line => user_spec.merge_into(&mut specs.line),
+                OutType::Column => user_spec.merge_into(&mut specs.column),
                 OutType::Match => user_spec.merge_into(&mut specs.matched),
             }
         }
@@ -642,6 +647,11 @@ impl ColorSpecs {
         &self.line
     }
 
+    /// Return the color specification for coloring column numbers.
+    fn column(&self) -> &ColorSpec {
+        &self.column
+    }
+
     /// Return the color specification for coloring matched text.
     fn matched(&self) -> &ColorSpec {
         &self.matched
@@ -717,6 +727,7 @@ impl FromStr for OutType {
         match &*s.to_lowercase() {
             "path" => Ok(OutType::Path),
             "line" => Ok(OutType::Line),
+            "column" => Ok(OutType::Column),
             "match" => Ok(OutType::Match),
             _ => Err(Error::UnrecognizedOutType(s.to_string())),
         }
@@ -768,6 +779,7 @@ mod tests {
         assert_eq!(ColorSpecs::new(user_specs), ColorSpecs {
             path: ColorSpec::default(),
             line: ColorSpec::default(),
+            column: ColorSpec::default(),
             matched: expect_matched,
         });
     }
@@ -803,6 +815,12 @@ mod tests {
             ty: OutType::Line,
             value: SpecValue::None,
         });
+
+        let spec: Spec = "column:bg:green".parse().unwrap();
+        assert_eq!(spec, Spec {
+            ty: OutType::Column,
+            value: SpecValue::Bg(Color::Green),
+        });
     }
 
     #[test]