structopt to clap (#889)

Replace structopt with clap

Fixes #888

* Drop tests of deprecated options
They were failing

7 files changed, 531 insertions, 476 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 63df7763..79982fd9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -28,15 +28,6 @@ dependencies = [
 
 [[package]]
 name = "ansi_term"
-version = "0.11.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
-dependencies = [
- "winapi",
-]
-
-[[package]]
-name = "ansi_term"
 version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d52a9bb7ec0cf484c551830a7ce27bd20d67eac647e1befb56b0be4ee39a55d2"
@@ -172,17 +163,32 @@ dependencies = [
 
 [[package]]
 name = "clap"
-version = "2.33.3"
+version = "3.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37e58ac78573c40708d45522f0d80fa2f01cc4f9b4e2bf749807255454312002"
+checksum = "f6f34b09b9ee8c7c7b400fe2f8df39cafc9538b03d6ba7f4ae13e4cb90bfbb7d"
 dependencies = [
- "ansi_term 0.11.0",
  "atty",
  "bitflags",
+ "clap_derive",
+ "indexmap",
+ "lazy_static",
+ "os_str_bytes",
  "strsim",
+ "termcolor",
  "textwrap",
- "unicode-width",
- "vec_map",
+]
+
+[[package]]
+name = "clap_derive"
+version = "3.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41a0645a430ec9136d2d701e54a95d557de12649a9dd7109ced3187e648ac824"
+dependencies = [
+ "heck",
+ "proc-macro-error",
+ "proc-macro2",
+ "quote",
+ "syn",
 ]
 
 [[package]]
@@ -351,13 +357,14 @@ name = "git-delta"
 version = "0.11.3"
 dependencies = [
  "ansi_colours",
- "ansi_term 0.12.1",
+ "ansi_term",
  "atty",
  "bitflags",
  "box_drawing",
  "bytelines",
  "chrono",
  "chrono-humanize",
+ "clap",
  "console",
  "ctrlc",
  "dirs-next",
@@ -373,7 +380,6 @@ dependencies = [
  "serde_json",
  "shell-words",
  "smol_str",
- "structopt",
  "syntect",
  "sysinfo",
  "unicode-segmentation",
@@ -436,12 +442,9 @@ dependencies = [
 
 [[package]]
 name = "heck"
-version = "0.3.2"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "87cbf45460356b7deeb5e3415b5563308c0a9b057c85e12b06ad551f98d0a6ac"
-dependencies = [
- "unicode-segmentation",
-]
+checksum = "2540771e65fc8cb83cd6e8a237f70c319bd5c29f78ed1084ba5d50eeac86f7f9"
 
 [[package]]
 name = "hermit-abi"
@@ -571,9 +574,9 @@ checksum = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
 
 [[package]]
 name = "memchr"
-version = "2.3.4"
+version = "2.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
+checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
 
 [[package]]
 name = "memoffset"
@@ -664,6 +667,15 @@ dependencies = [
 ]
 
 [[package]]
+name = "os_str_bytes"
+version = "6.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e22443d1643a904602595ba1cd8f7d896afe56d26712531c5ff73a15b2fbf64"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
 name = "palette"
 version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -801,18 +813,18 @@ checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.24"
+version = "1.0.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e0704ee1a7e00d7bb417d0770ea303c1bccbabf0ef1667dae92b5967f5f8a71"
+checksum = "c7342d5883fbccae1cc37a2353b09c87c9b0f3afd73f5fb9bba687a1f733b029"
 dependencies = [
  "unicode-xid",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.8"
+version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "991431c3519a3f36861882da93630ce66b52918dcf1b8e2fd66b397fc96f28df"
+checksum = "47aa80447ce4daf1717500037052af176af5d38cc3e571d9ec1c7353fc10c87d"
 dependencies = [
  "proc-macro2",
 ]
@@ -990,39 +1002,15 @@ dependencies = [
 
 [[package]]
 name = "strsim"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
-
-[[package]]
-name = "structopt"
-version = "0.3.25"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "40b9788f4202aa75c240ecc9c15c65185e6a39ccdeb0fd5d008b98825464c87c"
-dependencies = [
- "clap",
- "lazy_static",
- "structopt-derive",
-]
-
-[[package]]
-name = "structopt-derive"
-version = "0.4.18"
+version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dcb5ae327f9cc13b68763b5749770cb9e048a99bd9dfdfa58d0cf05d5f64afe0"
-dependencies = [
- "heck",
- "proc-macro-error",
- "proc-macro2",
- "quote",
- "syn",
-]
+checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
 
 [[package]]
 name = "syn"
-version = "1.0.57"
+version = "1.0.85"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4211ce9909eb971f111059df92c45640aad50a619cf55cd76476be803c4c68e6"
+checksum = "a684ac3dcd8913827e18cd09a68384ee66c1de24157e3c556c9ab16d85695fb7"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1086,12 +1074,9 @@ dependencies = [
 
 [[package]]
 name = "textwrap"
-version = "0.11.0"
+version = "0.14.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d326610f408c7a4eb6f51c37c330e496b08506c9457c9d34287ecc38809fb060"
-dependencies = [
- "unicode-width",
-]
+checksum = "0066c8d12af8b5acd21e00547c3797fde4e8677254a7ee429176ccebbe93dd80"
 
 [[package]]
 name = "time"
@@ -1189,12 +1174,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b00bca6106a5e23f3eee943593759b7fcddb00554332e856d990c893966879fb"
 
 [[package]]
-name = "vec_map"
-version = "0.8.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f1bddf1187be692e79c5ffeab891132dfb0f236ed36a43c7ed39f1165ee20191"
-
-[[package]]
 name = "version_check"
 version = "0.9.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/Cargo.toml b/Cargo.toml
index 6f46bcf1..845e81d1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,6 +23,7 @@ atty = "0.2.14"
 bitflags = "1.3.2"
 box_drawing = "0.1.2"
 bytelines = "2.2.2"
+clap = { version = "3.0.5", features = ["derive"] }
 console = "0.15.0"
 ctrlc = "3.2.1"
 dirs-next = "2.0.0"
@@ -36,7 +37,6 @@ serde = { version = "1.0.118", features = ["derive"] }
 serde_json = "1.0.70"
 shell-words = "1.0.0"
 smol_str = "0.1.21"
-structopt = "0.3.25"
 unicode-segmentation = "1.8.0"
 unicode-width = "0.1.9"
 vte = "0.10.1"
diff --git a/src/cli.rs b/src/cli.rs
index ed169809..cbc828b1 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -2,26 +2,25 @@ use std::collections::{HashMap, HashSet};
 use std::ffi::OsString;
 use std::path::PathBuf;
 
+use clap::{AppSettings, ColorChoice, FromArgMatches, IntoApp, Parser};
 use lazy_static::lazy_static;
-use structopt::clap::AppSettings::{ColorAlways, ColoredHelp, DeriveDisplayOrder};
-use structopt::{clap, StructOpt};
 use syntect::highlighting::Theme as SyntaxTheme;
 use syntect::parsing::SyntaxSet;
 
+use crate::config::delta_unreachable;
 use crate::git_config::{GitConfig, GitConfigEntry};
 use crate::options;
 use crate::utils::bat::assets::HighlightingAssets;
 use crate::utils::bat::output::PagingMode;
 
-// No Default trait as this ignores `default_value = ..`
-#[derive(StructOpt)]
-#[structopt(
+#[derive(Parser)]
+#[clap(
     name = "delta",
     about = "A viewer for git and diff output",
-    setting(ColorAlways),
-    setting(ColoredHelp),
-    setting(DeriveDisplayOrder),
-    after_help = "\
+    version,
+    color = ColorChoice::Always,
+    setting(AppSettings::DeriveDisplayOrder),
+    after_long_help = "\
 GIT CONFIG
 ----------
 
@@ -204,632 +203,746 @@ https://github.com/dandavison/delta/issues.
 "
 )]
 pub struct Opt {
-    /// Use default colors appropriate for a light terminal background. For more control, see the
-    /// style options and --syntax-theme.
-    #[structopt(long = "light")]
+    #[clap(long = "light")]
+    /// Use default colors appropriate for a light terminal background.
+    ///
+    /// For more control, see the style options and --syntax-theme.
     pub light: bool,
 
-    /// Use default colors appropriate for a dark terminal background. For more control, see the
-    /// style options and --syntax-theme.
-    #[structopt(long = "dark")]
+    #[clap(long = "dark")]
+    /// Use default colors appropriate for a dark terminal background.
+    ///
+    /// For more control, see the style options and --syntax-theme.
     pub dark: bool,
 
-    /// Display line numbers next to the diff. See LINE NUMBERS section.
-    #[structopt(short = "n", long = "line-numbers")]
+    #[clap(short = 'n', long = "line-numbers")]
+    /// Display line numbers next to the diff.
+    ///
+    /// See LINE NUMBERS section.
     pub line_numbers: bool,
 
-    /// Display a side-by-side diff view instead of the traditional view.
-    #[structopt(short = "s", long = "side-by-side")]
+    #[clap(short = 's', long = "side-by-side")]
+    /// Display diffs in side-by-side layout.
     pub side_by_side: bool,
 
-    #[structopt(long = "diff-highlight")]
-    /// Emulate diff-highlight (https://github.com/git/git/tree/master/contrib/diff-highlight)
+    #[clap(long = "diff-highlight")]
+    /// Emulate diff-highlight.
+    ///
+    /// (https://github.com/git/git/tree/master/contrib/diff-highlight)
     pub diff_highlight: bool,
 
-    #[structopt(long = "diff-so-fancy")]
-    /// Emulate diff-so-fancy (https://github.com/so-fancy/diff-so-fancy)
+    #[clap(long = "diff-so-fancy")]
+    /// Emulate diff-so-fancy.
+    ///
+    /// (https://github.com/so-fancy/diff-so-fancy)
     pub diff_so_fancy: bool,
 
-    #[structopt(long = "navigate")]
-    /// Activate diff navigation: use n to jump forwards and N to jump backwards. To change the
-    /// file labels used see --file-modified-label, --file-removed-label, --file-added-label,
-    /// --file-renamed-label.
+    #[clap(long = "navigate")]
+    /// Activate diff navigation.
+    ///
+    /// Use n to jump forwards and N to jump backwards. To change the file labels used see
+    /// --file-modified-label, --file-removed-label, --file-added-label, --file-renamed-label.
     pub navigate: bool,
 
-    #[structopt(long = "relative-paths")]
-    /// Output all file paths relative to the current directory so that they
-    /// resolve correctly when clicked on or used in shell commands.
+    #[clap(long = "relative-paths")]
+    /// Output all file paths relative to the current directory.
+    ///
+    /// This means that they will resolve correctly when clicked on or used in shell commands.
     pub relative_paths: bool,
 
-    #[structopt(long = "hyperlinks")]
-    /// Render commit hashes, file names, and line numbers as hyperlinks,
-    /// according to the hyperlink spec for terminal emulators:
-    /// https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda. By
-    /// default, file names and line numbers link to the local file using a file
-    /// URL, whereas commit hashes link to the commit in GitHub, if the remote
-    /// repository is hosted by GitHub. See --hyperlinks-file-link-format for
-    /// full control over the file URLs emitted. Hyperlinks are supported by
-    /// several common terminal emulators. To make them work, you must use less
-    /// version >= 581 with the -R flag (or use -r with older less versions, but
-    /// this will break e.g. --navigate). If you use tmux, then you will also
-    /// need a patched fork of tmux (see https://github.com/dandavison/tmux).
+    #[clap(long = "hyperlinks")]
+    /// Render commit hashes, file names, and line numbers as hyperlinks.
+    ///
+    /// Following the hyperlink spec for terminal emulators:
+    /// https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda. By default, file names
+    /// and line numbers link to the local file using a file URL, whereas commit hashes link to the
+    /// commit in GitHub, if the remote repository is hosted by GitHub. See
+    /// --hyperlinks-file-link-format for full control over the file URLs emitted. Hyperlinks are
+    /// supported by several common terminal emulators. To make them work, you must use less version
+    /// >= 581 with the -R flag (or use -r with older less versions, but this will break e.g.
+    /// --navigate). If you use tmux, then you will also need a patched fork of tmux (see
+    /// https://github.com/dandavison/tmux).
     pub hyperlinks: bool,
 
-    #[structopt(long = "keep-plus-minus-markers")]
-    /// Prefix added/removed lines with a +/- character, exactly as git does. By default, delta
-    /// does not emit any prefix, so code can be copied directly from delta's output.
+    #[clap(long = "keep-plus-minus-markers")]
+    /// Prefix added/removed lines with a +/- character, as git does.
+    ///
+    /// By default, delta does not emit any prefix, so code can be copied directly from delta's
+    /// output.
     pub keep_plus_minus_markers: bool,
 
-    /// Display the active values for all Delta options. Style options are displayed with
-    /// foreground and background colors. This can be used to experiment with colors by combining
-    /// this option with other options such as --minus-style, --zero-style, --plus-style, --light,
-    /// --dark, etc.
-    #[structopt(long = "show-config")]
+    #[clap(long = "show-config")]
+    /// Display the active values for all Delta options.
+    ///
+    /// Style string options are displayed with foreground and background colors. This can be used to
+    /// experiment with colors by combining this option with other options such as --minus-style,
+    /// --zero-style, --plus-style, --light, --dark, etc.
     pub show_config: bool,
 
+    #[clap(long = "list-languages")]
     /// List supported languages and associated file extensions.
-    #[structopt(long = "list-languages")]
     pub list_languages: bool,
 
+    #[clap(long = "list-syntax-themes")]
     /// List available syntax-highlighting color themes.
-    #[structopt(long = "list-syntax-themes")]
     pub list_syntax_themes: bool,
 
-    /// Show all available syntax-highlighting themes, each with an example of highlighted diff output.
+    #[clap(long = "show-syntax-themes")]
+    /// Show example diff for available syntax-highlighting themes.
+    ///
     /// If diff output is supplied on standard input then this will be used for the demo. For
     /// example: `git show | delta --show-syntax-themes`.
-    #[structopt(long = "show-syntax-themes")]
     pub show_syntax_themes: bool,
 
-    /// Show available delta themes, each with an example of highlighted diff
-    /// output. A delta theme is a delta named feature (see --features) that
-    /// sets either `light` or `dark`. See
-    /// https://github.com/dandavison/delta#custom-color-themes. If diff output
-    /// is supplied on standard input then this will be used for the demo. For
-    /// example: `git show | delta --show-themes`. By default shows dark or
-    /// light themes only, according to whether delta is in dark or light mode
-    /// (as set by the user or inferred from BAT_THEME). To control the themes
-    /// shown, use --dark or --light, or both, on the command line together with
-    /// this option.
-    #[structopt(long = "show-themes")]
+    #[clap(long = "show-themes")]
+    /// Show example diff for available delta themes.
+    ///
+    /// A delta theme is a delta named feature (see --features) that sets either `light` or `dark`.
+    /// See https://github.com/dandavison/delta#custom-color-themes. If diff output is supplied on
+    /// standard input then this will be used for the demo. For example: `git show | delta
+    /// --show-themes`. By default shows dark or light themes only, according to whether delta is in
+    /// dark or light mode (as set by the user or inferred from BAT_THEME). To control the themes
+    /// shown, use --dark or --light, or both, on the command line together with this option.
     pub show_themes: bool,
 
-    /// Show available named colors. In addition to named colors, arbitrary
-    /// colors can be specified using RGB hex codes. See COLORS section.
-    #[structopt(long = "show-colors")]
+    #[clap(long = "show-colors")]
+    /// Show available named colors.
+    ///
+    /// In addition to named colors, arbitrary colors can be specified using RGB hex codes. See
+    /// COLORS section.
     pub show_colors: bool,
 
-    /// Parse ANSI color escape sequences in input and display them as git style
-    /// strings. Example usage: git show --color=always | delta --parse-ansi
+    #[clap(long = "parse-ansi")]
+    /// Display ANSI color escape sequences in human-readable form.
+    ///
+    /// Example usage: git show --color=always | delta --parse-ansi
     /// This can be used to help identify input style strings to use with map-styles.
-    #[structopt(long = "parse-ansi")]
     pub parse_ansi: bool,
 
-    #[structopt(long = "no-gitconfig")]
-    /// Do not take any settings from git config. See GIT CONFIG section.
+    #[clap(long = "no-gitconfig")]
+    /// Do not read any settings from git config.
+    ///
+    /// See GIT CONFIG section.
     pub no_gitconfig: bool,
 
-    #[structopt(long = "raw")]
-    /// Do not alter the input in any way. This is mainly intended for testing delta.
+    #[clap(long = "raw")]
+    /// Do not alter the input in any way.
+    ///
+    /// This is mainly intended for testing delta.
     pub raw: bool,
 
-    #[structopt(long = "color-only")]
-    /// Do not alter the input structurally in any way, but color and highlight hunk lines
-    /// according to your delta configuration. This is mainly intended for other tools that use
-    /// delta.
+    #[clap(long = "color-only")]
+    /// Do not alter the input structurally in any way.
+    ///
+    /// But color and highlight hunk lines according to your delta configuration. This is mainly
+    /// intended for other tools that use delta.
     pub color_only: bool,
 
     ////////////////////////////////////////////////////////////////////////////////////////////
-    #[structopt(long = "features")]
-    /// Name of delta features to use (space-separated). A feature is a named collection of delta
-    /// options in ~/.gitconfig. See FEATURES section. The environment variable DELTA_FEATURES can
-    /// be set to a space-separated list of feature names. If this is preceded with a space, the
-    /// features from the environment variable will be added to those specified in git config. E.g.
-    /// DELTA_FEATURES=+side-by-side can be used to activate side-by-side temporarily.
+    #[clap(long = "features")]
+    /// Names of delta features to activate (space-separated).
+    ///
+    /// A feature is a named collection of delta options in ~/.gitconfig. See FEATURES section. The
+    /// environment variable DELTA_FEATURES can be set to a space-separated list of feature names.
+    /// If this is preceded with a space, the features from the environment variable will be added
+    /// to those specified in git config. E.g. DELTA_FEATURES=+side-by-side can be used to activate
+    /// side-by-side temporarily.
     pub features: Option<String>,
 
-    #[structopt(long = "syntax-theme")]
-    /// The code syntax-highlighting theme to use. Use --show-syntax-themes to demo available
-    /// themes. Defaults to the value of the BAT_THEME environment variable, if that contains a
-    /// valid theme name. --syntax-theme=none disables all syntax highlighting.
+    #[clap(long = "syntax-theme")]
+    /// The syntax-highlighting theme to use.
+    ///
+    /// Use --show-syntax-themes to demo available themes. Defaults to the value of the BAT_THEME
+    /// environment variable, if that contains a valid theme name. --syntax-theme=none disables all
+    /// syntax highlighting.
     pub syntax_theme: Option<String>,
 
-    #[structopt(long = "minus-style", default_value = "normal auto")]
-    /// Style (foreground, background, attributes) for removed lines. See STYLES section.
+    #[clap(long = "minus-style", default_value = "normal auto")]
+    /// Style string for removed lines.
+    ///
+    /// See STYLES section.
     pub minus_style: String,
 
-    #[structopt(long = "zero-style", default_value = "syntax normal")]
-    /// Style (foreground, background, attributes) for unchanged lines. See STYLES section.
+    #[clap(long = "zero-style", default_value = "syntax normal")]
+    /// Style string for unchanged lines.
+    ///
+    /// See STYLES section.
     pub zero_style: String,
 
-    #[structopt(long = "plus-style", default_value = "syntax auto")]
-    /// Style (foreground, background, attributes) for added lines. See STYLES section.
+    #[clap(long = "plus-style", default_value = "syntax auto")]
+    /// Style string for added lines.
+    ///
+    /// See STYLES section.
     pub plus_style: String,
 
-    #[structopt(long = "minus-emph-style", default_value = "normal auto")]
-    /// Style (foreground, background, attributes) for emphasized sections of removed lines. See
-    /// STYLES section.
+    #[clap(long = "minus-emph-style", default_value = "normal auto")]
+    /// Style string for emphasized sections of removed lines.
+    ///
+    /// See STYLES section.
     pub minus_emph_style: String,
 
-    #[structopt(long = "minus-non-emph-style", default_value = "minus-style")]
-    /// Style (foreground, background, attributes) for non-emphasized sections of removed lines
-    /// that have an emphasized section. See STYLES section.
+    #[clap(long = "minus-non-emph-style", default_value = "minus-style")]
+    /// Style string for non-emphasized sections of removed lines that have an emphasized section.
+    ///
+    /// See STYLES section.
     pub minus_non_emph_style: String,
 
-    #[structopt(long = "plus-emph-style", default_value = "syntax auto")]
-    /// Style (foreground, background, attributes) for emphasized sections of added lines. See
-    /// STYLES section.
+    #[clap(long = "plus-emph-style", default_value = "syntax auto")]
+    /// Style string for emphasized sections of added lines.
+    ///
+    /// See STYLES section.
     pub plus_emph_style: String,
 
-    #[structopt(long = "plus-non-emph-style", default_value = "plus-style")]
-    /// Style (foreground, background, attributes) for non-emphasized sections of added lines that
-    /// have an emphasized section. See STYLES section.
+    #[clap(long = "plus-non-emph-style", default_value = "plus-style")]
+    /// Style string for non-emphasized sections of added lines that have an emphasized section.
+    ///
+    /// See STYLES section.
     pub plus_non_emph_style: String,
 
-    #[structopt(long = "commit-style", default_value = "raw")]
-    /// Style (foreground, background, attributes) for the commit hash line. See STYLES section.
-    /// The style 'omit' can be used to remove the commit hash line from the output.
+    #[clap(long = "commit-style", default_value = "raw")]
+    /// Style string for the commit hash line.
+    ///
+    /// See STYLES section. The style 'omit' can be used to remove the commit hash line from the
+    /// output.
     pub commit_style: String,
 
-    #[structopt(long = "commit-decoration-style", default_value = "")]
-    /// Style (foreground, background, attributes) for the commit hash decoration. See STYLES
-    /// section. The style string should contain one of the special attributes 'box', 'ul'
-    /// (underline), 'ol' (overline), or the combination 'ul ol'.
+    #[clap(long = "commit-decoration-style", default_value = "")]
+    /// Style string for the commit hash decoration.
+    ///
+    /// See STYLES section. The style string should contain one of the special attributes 'box',
+    /// 'ul' (underline), 'ol' (overline), or the combination 'ul ol'.
     pub commit_decoration_style: String,
 
-    /// The regular expression used to identify the commit line when parsing git output.
-    #[structopt(long = "commit-regex", default_value = r"^commit ")]
+    #[clap(long = "commit-regex", default_value = r"^commit ")]
+    /// Regular expression used to identify the commit line when parsing git output.
     pub commit_regex: String,
 
-    #[structopt(long = "file-style", default_value = "blue")]
-    /// Style (foreground, background, attributes) for the file section. See STYLES section. The
-    /// style 'omit' can be used to remove the file section from the output.
+    #[clap(long = "file-style", default_value = "blue")]
+    /// Style string for the file section.
+    ///
+    /// See STYLES section. The style 'omit' can be used to remove the file section from the output.
     pub file_style: String,
 
-    #[structopt(long = "file-decoration-style", default_value = "blue ul")]
-    /// Style (foreground, background, attributes) for the file decoration. See STYLES section. The
-    /// style string should contain one of the special attributes 'box', 'ul' (underline), 'ol'
-    /// (overline), or the combination 'ul ol'.
+    #[clap(long = "file-decoration-style", default_value = "blue ul")]
+    /// Style string for the file decoration.
+    ///
+    /// See STYLES section. The style string should contain one of the special attributes 'box',
+    /// 'ul' (underline), 'ol' (overline), or the combination 'ul ol'.
     pub file_decoration_style: String,
 
     #[structopt(long = "file-transformation")]
-    /// A sed-style command specifying how file paths should be transformed for display.
+    /// A sed-style command transforming file paths for display.
     pub file_regex_replacement: Option<String>,
 
-    /// Format string for commit hyperlinks (requires --hyperlinks). The
-    /// placeholder "{commit}" will be replaced by the commit hash. For example:
+    #[clap(long = "hyperlinks-commit-link-format")]
+    /// Format string for commit hyperlinks (requires --hyperlinks).
+    ///
+    /// The placeholder "{commit}" will be replaced by the commit hash. For example:
     /// --hyperlinks-commit-link-format='https://mygitrepo/{commit}/'
-    #[structopt(long = "hyperlinks-commit-link-format")]
     pub hyperlinks_commit_link_format: Option<String>,
 
-    /// Format string for file hyperlinks (requires --hyperlinks). The
-    /// placeholders "{path}" and "{line}" will be replaced by the absolute file
-    /// path and the line number, respectively. The default value of this option
-    /// creates hyperlinks using standard file URLs; your operating system
-    /// should open these in the application registered for that file type.
-    /// However, these do not make use of the line number. In order for the link
-    /// to open the file at the correct line number, you could use a custom URL
-    /// format such as "file-line://{path}:{line}" and register an application
-    /// to handle the custom "file-line" URL scheme by opening the file in your
-    /// editor/IDE at the indicated line number. See
+    #[clap(long = "hyperlinks-file-link-format", default_value = "file://{path}")]
+    /// Format string for file hyperlinks (requires --hyperlinks).
+    ///
+    /// The placeholders "{path}" and "{line}" will be replaced by the absolute file path and the
+    /// line number, respectively. The default value of this option creates hyperlinks using
+    /// standard file URLs; your operating system should open these in the application registered
+    /// for that file type. However, these do not make use of the line number. In order for the link
+    /// to open the file at the correct line number, you could use a custom URL format such as
+    /// "file-line://{path}:{line}" and register an application to handle the custom "file-line" URL
+    /// scheme by opening the file in your editor/IDE at the indicated line number. See
     /// https://github.com/dandavison/open-in-editor for an example.
-    #[structopt(long = "hyperlinks-file-link-format", default_value = "file://{path}")]
     pub hyperlinks_file_link_format: String,
 
-    #[structopt(long = "hunk-header-style", default_value = "line-number syntax")]
-    /// Style (foreground, background, attributes) for the hunk-header. See STYLES section. Special
-    /// attributes 'file' and 'line-number' can be used to include the file path, and number of
-    /// first hunk line, in the hunk header. The style 'omit' can be used to remove the hunk header
-    /// section from the output.
+    #[clap(long = "hunk-header-style", default_value = "line-number syntax")]
+    /// Style string for the hunk-header.
+    ///
+    /// See STYLES section. Special attributes 'file' and 'line-number' can be used to include the
+    /// file path, and number of first hunk line, in the hunk header. The style 'omit' can be used
+    /// to remove the hunk header section from the output.
     pub hunk_header_style: String,
 
-    #[structopt(long = "hunk-header-file-style", default_value = "blue")]
-    /// Style (foreground, background, attributes) for the file path part of the hunk-header. See
-    /// STYLES section. The file path will only be displayed if hunk-header-style contains the
+    #[clap(long = "hunk-header-file-style", default_value = "blue")]
+    /// Style string for the file path part of the hunk-header.
+    ///
+    /// See STYLES section. The file path will only be displayed if hunk-header-style contains the
     /// 'file' special attribute.
     pub hunk_header_file_style: String,
 
-    #[structopt(long = "hunk-header-line-number-style", default_value = "blue")]
-    /// Style (foreground, background, attributes) for the line number part of the hunk-header. See
-    /// STYLES section. The line number will only be displayed if hunk-header-style contains the
+    #[clap(long = "hunk-header-line-number-style", default_value = "blue")]
+    /// Style string for the line number part of the hunk-header.
+    ///
+    /// See STYLES section. The line number will only be displayed if hunk-header-style contains the
     /// 'line-number' special attribute.
     pub hunk_header_line_number_style: String,
 
-    #[structopt(long = "hunk-header-decoration-style", default_value = "blue box")]
-    /// Style (foreground, background, attributes) for the hunk-header decoration. See STYLES
-    /// section. The style string should contain one of the special attributes 'box', 'ul'
-    /// (underline), 'ol' (overline), or the combination 'ul ol'.
+    #[clap(long = "hunk-header-decoration-style", default_value = "blue box")]
+    /// Style string for the hunk-header decoration.
+    ///
+    /// See STYLES section. The style string should contain one of the special attributes 'box',
+    /// 'ul' (underline), 'ol' (overline), or the combination 'ul ol'.
     pub hunk_header_decoration_style: String,
 
-    #[structopt(long = "merge-conflict-begin-symbol", default_value = "▼")]
-    /// A string that is repeated to form the line marking the beginning of a merge conflict region.
+    #[clap(long = "merge-conflict-begin-symbol", default_value = "▼")]
+    /// String marking the beginning of a merge conflict region.
+    ///
+    /// The string will be repeated until it reaches the required length.
     pub merge_conflict_begin_symbol: String,
 
-    #[structopt(long = "merge-conflict-end-symbol", default_value = "▲")]
-    /// A string that is repeated to form the line marking the end of a merge conflict region.
+    #[clap(long = "merge-conflict-end-symbol", default_value = "▲")]
+    /// String marking the end of a merge conflict region.
+    ///
+    /// The string will be repeated until it reaches the required length.
     pub merge_conflict_end_symbol: String,
 
-    #[structopt(
+    #[clap(
         long = "merge-conflict-ours-diff-header-style",
         default_value = "normal"
     )]
-    /// Style (foreground, background, attributes) for the header above the diff between the
-    /// ancestral commit and 'our' branch. See STYLES section.
+    /// Style string for the header above the 'ours' branch merge conflict diff.
+    ///
+    /// See STYLES section.
     pub merge_conflict_ours_diff_header_style: String,
 
-    #[structopt(
+    #[clap(
         long = "merge-conflict-ours-diff-header-decoration-style",
         default_value = "box"
     )]
-    /// Style (foreground, background, attributes) for the decoration of the header above the diff
-    /// between the ancestral commit and 'our' branch.  See STYLES section. The style string should
-    /// contain one of the special attributes 'box', 'ul' (underline), 'ol' (overline), or the
-    /// combination 'ul ol'.
+    /// Style string for the decoration of the header above the 'ours' merge conflict diff.
+    ///
+    /// This styles the decoration of the header above the diff between the ancestral commit and the
+    /// 'ours' branch. See STYLES section. The