From dd91090a1ae931a604c51b9c6d7d8c9b46761af4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Mon, 15 Mar 2021 17:09:18 +0900
Subject: [PATCH] Implement keep_selections (filter selections on regex).

---
 helix-core/src/selection.rs | 35 +++++++++++++++++++++++++++--------
 helix-term/src/commands.rs  | 10 +++++++++-
 helix-term/src/keymap.rs    |  1 +
 helix-view/src/editor.rs    |  1 -
 4 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/helix-core/src/selection.rs b/helix-core/src/selection.rs
index ee925cbc..c34dff31 100644
--- a/helix-core/src/selection.rs
+++ b/helix-core/src/selection.rs
@@ -273,14 +273,33 @@ impl Selection {
 
 // TODO: checkSelection -> check if valid for doc length
 
+pub fn keep_matches(
+    text: RopeSlice,
+    selection: &Selection,
+    regex: &crate::regex::Regex,
+) -> Option<Selection> {
+    let result: SmallVec<_> = selection
+        .ranges()
+        .iter()
+        .filter(|range| regex.is_match(&range.fragment(text)))
+        .copied()
+        .collect();
+
+    // TODO: figure out a new primary index
+    if !result.is_empty() {
+        return Some(Selection::new(result, 0));
+    }
+    None
+}
+
 pub fn select_on_matches(
     text: RopeSlice,
-    selections: &Selection,
+    selection: &Selection,
     regex: &crate::regex::Regex,
 ) -> Option<Selection> {
-    let mut result = SmallVec::with_capacity(selections.ranges().len());
+    let mut result = SmallVec::with_capacity(selection.ranges().len());
 
-    for sel in selections.ranges() {
+    for sel in selection.ranges() {
         // TODO: can't avoid occasional allocations since Regex can't operate on chunks yet
         let fragment = sel.fragment(text);
 
@@ -309,12 +328,12 @@ pub fn select_on_matches(
 // TODO: support to split on capture #N instead of whole match
 pub fn split_on_matches(
     text: RopeSlice,
-    selections: &Selection,
+    selection: &Selection,
     regex: &crate::regex::Regex,
 ) -> Selection {
-    let mut result = SmallVec::with_capacity(selections.ranges().len());
+    let mut result = SmallVec::with_capacity(selection.ranges().len());
 
-    for sel in selections.ranges() {
+    for sel in selection.ranges() {
         // TODO: can't avoid occasional allocations since Regex can't operate on chunks yet
         let fragment = sel.fragment(text);
 
@@ -417,9 +436,9 @@ mod test {
 
         let text = Rope::from("abcd efg wrs   xyz 123 456");
 
-        let selections = Selection::new(smallvec![Range::new(0, 8), Range::new(10, 19),], 0);
+        let selection = Selection::new(smallvec![Range::new(0, 8), Range::new(10, 19),], 0);
 
-        let result = split_on_matches(text.slice(..), &selections, &Regex::new(r"\s+").unwrap());
+        let result = split_on_matches(text.slice(..), &selection, &Regex::new(r"\s+").unwrap());
 
         assert_eq!(
             result.ranges(),
diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index 36edde4c..d75fd694 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -1156,7 +1156,15 @@ pub fn join_selections(cx: &mut Context) {
 pub fn keep_selections(cx: &mut Context) {
     let doc = cx.doc();
     // keep selections matching regex
-    // and another method for inverse
+    let prompt = ui::regex_prompt(cx, "keep:".to_string(), |doc, regex| {
+        let text = doc.text().slice(..);
+
+        if let Some(selection) = selection::keep_matches(text, doc.selection(), &regex) {
+            doc.set_selection(selection);
+        }
+    });
+
+    cx.push_layer(Box::new(prompt));
 }
 
 //
diff --git a/helix-term/src/keymap.rs b/helix-term/src/keymap.rs
index 58a465fe..a365050f 100644
--- a/helix-term/src/keymap.rs
+++ b/helix-term/src/keymap.rs
@@ -207,6 +207,7 @@ pub fn default() -> Keymaps {
         key!('<') => commands::unindent,
         key!('=') => commands::format_selections,
         shift!('J') => commands::join_selections,
+        // TODO: conflicts hover/doc
         shift!('K') => commands::keep_selections,
 
         // key!('q') => commands::record_macro,
diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 01a2dac5..f79eadad 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -44,7 +44,6 @@ impl Editor {
             .and_then(|language| self.language_servers.get(language, &executor));
 
         if let Some(language_server) = language_server {
-            // TODO: do this everywhere
             doc.set_language_server(Some(language_server.clone()));
 
             smol::block_on(language_server.text_document_did_open(