Show blame line numbers via blame-line-number-suffix

Prefix and suffix of the format string are separator_style highlighted,
format options are off, {n}, {n:block}, {n:every-N}.

Add a FormatStringPlaceholderDataAnyPlaceholder template which works
without a borrowed Placeholder.

src/cli.rs

@@ -499,9 +499,14 @@ pub struct Opt {
     )]
     pub blame_format: String,
 
-    /// Separator between the commit metadata and code sections of a line of git blame output.
-    #[structopt(long = "blame-separator", default_value = "│")]
-    pub blame_separator: String,
+    /// Separator between the commit metadata and code sections of a line of git blame output. Contains
+    /// the line number by default. Possible values are "off" to disable line numbers or a format
+    /// string. This may contain one "{n}" placeholder and will display the line number on every line.
+    /// If the type is given as block ("{n:block}") the line number will only be shown when a new blame
+    /// block starts; or if it is given as "{n:every-N}" the line will be show with every block and every
+    /// N-th (modulo) line.
+    #[structopt(long = "blame-separator-format", default_value = "│{n:^4}│")]
+    pub blame_separator_format: String,
 
     #[structopt(long = "blame-separator-style")]
     /// Style (foreground, background, attributes) for the separator between the commit metadata and

src/config.rs

@@ -18,6 +18,8 @@ use crate::features::navigate;
 use crate::features::side_by_side::{self, ansifill, LeftRight};
 use crate::git_config::{GitConfig, GitConfigEntry};
 use crate::handlers;
+use crate::handlers::blame::parse_blame_line_numbers;
+use crate::handlers::blame::BlameLineNumbers;
 use crate::minusplus::MinusPlus;
 use crate::paint::BgFillMethod;
 use crate::parse_styles;
@@ -64,8 +66,8 @@ pub struct Config {
     pub background_color_extends_to_terminal_width: bool,
     pub blame_code_style: Option<Style>,
     pub blame_format: String,
+    pub blame_separator_format: BlameLineNumbers,
     pub blame_palette: Vec<String>,
-    pub blame_separator: String,
     pub blame_separator_style: Option<Style>,
     pub blame_timestamp_format: String,
     pub color_only: bool,
@@ -249,9 +251,9 @@ impl From<cli::Opt> for Config {
             blame_format: opt.blame_format,
             blame_code_style: styles.remove("blame-code-style"),
             blame_palette,
-            blame_separator: opt.blame_separator,
             blame_separator_style: styles.remove("blame-separator-style"),
             blame_timestamp_format: opt.blame_timestamp_format,
+            blame_separator_format: dbg!(parse_blame_line_numbers(&opt.blame_separator_format)),
             commit_style: styles["commit-style"],
             color_only: opt.color_only,
             commit_regex,

src/features/line_numbers.rs

@@ -335,12 +335,7 @@ pub mod tests {
             vec![format::FormatStringPlaceholderData {
                 prefix: "".into(),
                 placeholder: Some(Placeholder::NumberMinus),
-                alignment_spec: None,
-                width: None,
-                precision: None,
-                suffix: "".into(),
-                prefix_len: 0,
-                suffix_len: 0,
+                ..Default::default()
             }]
         )
     }
@@ -354,10 +349,7 @@ pub mod tests {
                 placeholder: Some(Placeholder::NumberPlus),
                 alignment_spec: None,
                 width: Some(4),
-                precision: None,
-                suffix: "".into(),
-                prefix_len: 0,
-                suffix_len: 0,
+                ..Default::default()
             }]
         )
     }
@@ -372,9 +364,7 @@ pub mod tests {
                 alignment_spec: Some(Align::Right),
                 width: Some(4),
                 precision: None,
-                suffix: "".into(),
-                prefix_len: 0,
-                suffix_len: 0,
+                ..Default::default()
             }]
         )
     }
@@ -388,10 +378,7 @@ pub mod tests {
                 placeholder: Some(Placeholder::NumberPlus),
                 alignment_spec: Some(Align::Right),
                 width: Some(4),
-                precision: None,
-                suffix: "".into(),
-                prefix_len: 0,
-                suffix_len: 0,
+                ..Default::default()
             }]
         )
     }
@@ -409,6 +396,7 @@ pub mod tests {
                 suffix: "@@".into(),
                 prefix_len: 2,
                 suffix_len: 2,
+                ..Default::default()
             }]
         )
     }
@@ -427,6 +415,7 @@ pub mod tests {
                     suffix: "@@---{np:_>4}**".into(),
                     prefix_len: 2,
                     suffix_len: 15,
+                    ..Default::default()
                 },
                 format::FormatStringPlaceholderData {
                     prefix: "@@---".into(),
@@ -437,6 +426,7 @@ pub mod tests {
                     suffix: "**".into(),
                     prefix_len: 5,
                     suffix_len: 2,
+                    ..Default::default()
                 }
             ]
         )
@@ -455,6 +445,7 @@ pub mod tests {
                 suffix: "__@@---**".into(),
                 prefix_len: 0,
                 suffix_len: 9,
+                ..Default::default()
             },]
         )
     }
@@ -472,6 +463,7 @@ pub mod tests {
                 suffix: "|".into(),
                 prefix_len: 2,
                 suffix_len: 1,
+                ..Default::default()
             }]
         );
     }
@@ -494,6 +486,7 @@ pub mod tests {
                     suffix: "+{np:<4}|".into(),
                     prefix_len: 2,
                     suffix_len: 9,
+                    ..Default::default()
                 },
                 format::FormatStringPlaceholderData {
                     prefix: "+".into(),
@@ -504,6 +497,7 @@ pub mod tests {
                     suffix: "|".into(),
                     prefix_len: 1,
                     suffix_len: 1,
+                    ..Default::default()
                 }
             ]
         );
@@ -521,6 +515,7 @@ pub mod tests {
                 suffix: "|++|".into(),
                 prefix_len: 1,
                 suffix_len: 4,
+                ..Default::default()
             }]
         );
     }
@@ -543,6 +538,7 @@ pub mod tests {
                 precision: None,
                 suffix: long.into(),
                 suffix_len: long.len(),
+                ..Default::default()
             },]
         )
     }