write to search registers when selecting by regex

helix-core/src/selection.rs

@@ -783,13 +783,15 @@ pub fn select_on_matches(
     text: RopeSlice,
     selection: &Selection,
     regex: &rope::Regex,
-) -> Option<Selection> {
+) -> Option<(Selection, Vec<Vec<String>>)> {
     let mut result = SmallVec::with_capacity(selection.len());
+    let mut captures = vec![vec![]; regex.captures_len()];
 
     for sel in selection {
-        for mat in regex.find_iter(text.regex_input_at(sel.from()..sel.to())) {
+        for cap in regex.captures_iter(text.regex_input_at(sel.from()..sel.to())) {
             // TODO: retain range direction
 
+            let mat = cap.get_match().unwrap();
             let start = text.byte_to_char(mat.start());
             let end = text.byte_to_char(mat.end());
 
@@ -798,13 +800,20 @@ pub fn select_on_matches(
             // These invalid matches can come from using RegEx anchors like `^`, `$`
             if range != Range::point(sel.to()) {
                 result.push(range);
+                for (i, captures) in captures.iter_mut().enumerate() {
+                    captures.push(
+                        cap.get_group(i)
+                            .map(|group| text.slice(group.range()).to_string())
+                            .unwrap_or_default(),
+                    );
+                }
             }
         }
     }
 
     // TODO: figure out a new primary index
     if !result.is_empty() {
-        return Some(Selection::new(result, 0));
+        return Some((Selection::new(result, 0), captures));
     }
 
     None
@@ -1099,9 +1108,9 @@ mod test {
         let selection = Selection::single(0, r.len_chars());
         assert_eq!(
             select_on_matches(s, &selection, &rope::Regex::new(r"[A-Z][a-z]*").unwrap()),
-            Some(Selection::new(
-                smallvec![Range::new(0, 6), Range::new(19, 26)],
-                0
+            Some((
+                Selection::new(smallvec![Range::new(0, 6), Range::new(19, 26)], 0),
+                vec![vec!["Nobody".to_string(), "Spanish".to_string()]]
             ))
         );
 
@@ -1120,7 +1129,7 @@ mod test {
         // line without ending
         assert_eq!(
             select_on_matches(s, &Selection::single(0, 4), &start_of_line),
-            Some(Selection::single(0, 0))
+            Some((Selection::single(0, 0), vec![vec!["".to_string()]]))
         );
         assert_eq!(
             select_on_matches(s, &Selection::single(0, 4), &end_of_line),
@@ -1129,23 +1138,23 @@ mod test {
         // line with ending
         assert_eq!(
             select_on_matches(s, &Selection::single(0, 5), &start_of_line),
-            Some(Selection::single(0, 0))
+            Some((Selection::single(0, 0), vec![vec!["".to_string()]]))
         );
         assert_eq!(
             select_on_matches(s, &Selection::single(0, 5), &end_of_line),
-            Some(Selection::single(4, 4))
+            Some((Selection::single(4, 4), vec![vec!["".to_string()]]))
         );
         // line with start of next line
         assert_eq!(
             select_on_matches(s, &Selection::single(0, 6), &start_of_line),
-            Some(Selection::new(
-                smallvec![Range::point(0), Range::point(5)],
-                0
+            Some((
+                Selection::new(smallvec![Range::point(0), Range::point(5)], 0),
+                vec![vec!["".to_string(), "".to_string()]]
             ))
         );
         assert_eq!(
             select_on_matches(s, &Selection::single(0, 6), &end_of_line),
-            Some(Selection::single(4, 4))
+            Some((Selection::single(4, 4), vec![vec!["".to_string()]]))
         );
 
         // multiple lines
@@ -1158,9 +1167,16 @@ mod test {
                     .build(r"^[a-z ]*$")
                     .unwrap()
             ),
-            Some(Selection::new(
+            Some((
+                Selection::new(
                     smallvec![Range::point(12), Range::new(13, 30), Range::new(31, 36)],
                     0
+                ),
+                vec![vec![
+                    "".to_string(),
+                    "contains multiple".to_string(),
+                    "lines".to_string()
+                ]]
             ))
         );
     }

helix-term/src/commands.rs

@@ -2012,10 +2012,11 @@ fn select_regex(cx: &mut Context) {
                 return;
             }
             let text = doc.text().slice(..);
-            if let Some(selection) =
+            if let Some((selection, captures)) =
                 selection::select_on_matches(text, doc.selection(view.id), &regex)
             {
                 doc.set_selection(view.id, selection);
+                cx.editor.registers.write_search_results(captures);
             } else {
                 cx.editor.set_error("nothing selected");
             }

helix-view/src/register.rs

@@ -80,7 +80,9 @@ impl Registers {
     pub fn write(&mut self, name: char, mut values: Vec<String>) -> Result<()> {
         match name {
             '_' => Ok(()),
-            '#' | '.' | '%' => Err(anyhow::anyhow!("Register {name} does not support writing")),
+            '#' | '.' | '%' | '&' | '1'..='9' => {
+                Err(anyhow::anyhow!("Register {name} does not support writing"))
+            }
             '*' | '+' => {
                 self.clipboard_provider.load().set_contents(
                     &values.join(NATIVE_LINE_ENDING.as_str()),
@@ -105,7 +107,9 @@ impl Registers {
     pub fn push(&mut self, name: char, mut value: String) -> Result<()> {
         match name {
             '_' => Ok(()),
-            '#' | '.' | '%' => Err(anyhow::anyhow!("Register {name} does not support pushing")),
+            '#' | '.' | '%' | '&' | '1'..='9' => {
+                Err(anyhow::anyhow!("Register {name} does not support pushing"))
+            }
             '*' | '+' => {
                 let clipboard_type = match name {
                     '+' => ClipboardType::Clipboard,
@@ -140,6 +144,17 @@ impl Registers {
         }
     }
 
+    pub fn write_search_results(&mut self, search_results: Vec<Vec<String>>) {
+        let len = search_results.len();
+        for (i, mut values) in search_results.into_iter().enumerate() {
+            values.reverse();
+            self.inner.insert(search_register_name(i), values);
+        }
+        for i in len..=9 {
+            self.inner.remove(&search_register_name(i));
+        }
+    }
+
     pub fn first<'a>(&'a self, name: char, editor: &'a Editor) -> Option<Cow<'a, str>> {
         self.read(name, editor).and_then(|mut values| values.next())
     }
@@ -168,6 +183,16 @@ impl Registers {
                     ('%', "<document path>"),
                     ('+', "<system clipboard>"),
                     ('*', "<primary clipboard>"),
+                    ('&', "<last regex match>"),
+                    ('1', "<last regex match group 1>"),
+                    ('2', "<last regex match group 2>"),
+                    ('3', "<last regex match group 3>"),
+                    ('4', "<last regex match group 4>"),
+                    ('5', "<last regex match group 5>"),
+                    ('6', "<last regex match group 6>"),
+                    ('7', "<last regex match group 7>"),
+                    ('8', "<last regex match group 8>"),
+                    ('9', "<last regex match group 9>"),
                 ]
                 .iter()
                 .copied(),
@@ -192,7 +217,7 @@ impl Registers {
 
                 true
             }
-            '_' | '#' | '.' | '%' => false,
+            '_' | '#' | '.' | '%' | '&' | '1'..='9' => false,
             _ => self.inner.remove(&name).is_some(),
         }
     }
@@ -218,6 +243,14 @@ impl Registers {
     }
 }
 
+fn search_register_name(i: usize) -> char {
+    if i == 0 {
+        '&'
+    } else {
+        char::from(i as u8 + b'0')
+    }
+}
+
 fn read_from_clipboard<'a>(
     provider: &ClipboardProvider,
     saved_values: Option<&'a Vec<String>>,