Handle grep output

- Handle standard filepath:code and filepath:line_number:code output
  as produced by `git grep`, `rg -H`, `grep -H`, etc (with -n for line
  numbers).

- Retain the match highlighting as produced by the grep tool, and
  expose it in delta's color output styled with grep-match-style.
  (Note that --color=always is needed to retain the color if piping
  into delta, but not for `git grep` when delta is configured as git's
  pager)

- Special handling of -p, and -W options of `git grep`: these display
  the function context in which the matches occur.

- `navigate` keybindings jump between match function contexts under
  `git grep -p` and between matching lines under `git grep -W`.

Thanks @zachriggle for the proposal.
Fixes #769

1 files changed, 12 insertions, 0 deletions

diff --git a/src/config.rs b/src/config.rs
index 71aa8382..12b82945 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -80,6 +80,12 @@ pub struct Config {
     pub git_config: Option<GitConfig>,
     pub git_minus_style: Style,
     pub git_plus_style: Style,
+    pub grep_context_line_style: Style,
+    pub grep_file_style: Style,
+    pub grep_line_number_style: Style,
+    pub grep_match_line_style: Style,
+    pub grep_match_word_style: Style,
+    pub grep_separator_symbol: String,
     pub hunk_header_file_style: Style,
     pub hunk_header_line_number_style: Style,
     pub hunk_header_style_include_file_path: bool,
@@ -243,6 +249,12 @@ impl From<cli::Opt> for Config {
             file_style: styles["file-style"],
             git_config: opt.git_config,
             git_config_entries: opt.git_config_entries,
+            grep_context_line_style: styles["grep-context-line-style"],
+            grep_file_style: styles["grep-file-style"],
+            grep_line_number_style: styles["grep-line-number-style"],
+            grep_match_line_style: styles["grep-match-line-style"],
+            grep_match_word_style: styles["grep-match-word-style"],
+            grep_separator_symbol: opt.grep_separator_symbol,
             hunk_header_file_style: styles["hunk-header-file-style"],
             hunk_header_line_number_style: styles["hunk-header-line-number-style"],
             hunk_header_style: styles["hunk-header-style"],