From b08278807ee51e279c07dd6b7955713455a4c654 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Sun, 13 Sep 2020 20:04:16 +0900
Subject: [PATCH] Add 'A', 'I' commands.

---
 helix-core/src/commands.rs    | 78 +++++++++++++++++++++++++++++++++++
 helix-core/src/transaction.rs |  8 ++++
 helix-term/src/keymap.rs      |  8 ++++
 3 files changed, 94 insertions(+)

diff --git a/helix-core/src/commands.rs b/helix-core/src/commands.rs
index 836667a1c..914ca0fe1 100644
--- a/helix-core/src/commands.rs
+++ b/helix-core/src/commands.rs
@@ -60,8 +60,86 @@ pub fn append_mode(state: &mut State, _count: usize) {
     })
 }
 
+// TODO: I, A, o and O can share a lot of the primitives.
+
 // I inserts at the start of each line with a selection
+pub fn prepend_to_line(state: &mut State, _count: usize) {
+    state.mode = Mode::Insert;
+
+    // calculate line numbers for each selection range
+    let mut lines = state
+        .selection
+        .ranges()
+        .iter()
+        .map(|range| state.doc.char_to_line(range.head))
+        .collect::<Vec<_>>();
+
+    lines.sort();
+    lines.dedup();
+
+    let positions: Vec<_> = lines
+        .into_iter()
+        .map(|index| {
+            // adjust all positions to the end of the line.
+            let line_start = state.doc.line_to_char(index);
+            line_start
+        })
+        .collect();
+
+    let selection = Selection::new(
+        positions
+            .iter()
+            .copied()
+            .map(|pos| Range::new(pos, pos))
+            .collect(),
+        0,
+    );
+
+    let transaction = Transaction::new(state).with_selection(selection);
+
+    transaction.apply(state);
+    // TODO: need to store into history if successful
+}
+
 // A inserts at the end of each line with a selection
+pub fn append_to_line(state: &mut State, _count: usize) {
+    state.mode = Mode::Insert;
+
+    // calculate line numbers for each selection range
+    let mut lines = state
+        .selection
+        .ranges()
+        .iter()
+        .map(|range| state.doc.char_to_line(range.head))
+        .collect::<Vec<_>>();
+
+    lines.sort();
+    lines.dedup();
+
+    let positions: Vec<_> = lines
+        .into_iter()
+        .map(|index| {
+            // adjust all positions to the end of the line.
+            let line = state.doc.line(index);
+            let line_start = state.doc.line_to_char(index);
+            line_start + line.len_chars() - 1
+        })
+        .collect();
+
+    let selection = Selection::new(
+        positions
+            .iter()
+            .copied()
+            .map(|pos| Range::new(pos, pos))
+            .collect(),
+        0,
+    );
+
+    let transaction = Transaction::new(state).with_selection(selection);
+
+    transaction.apply(state);
+    // TODO: need to store into history if successful
+}
 
 // o inserts a new line after each line with a selection
 pub fn open_below(state: &mut State, _count: usize) {
diff --git a/helix-core/src/transaction.rs b/helix-core/src/transaction.rs
index 3d03de193..12ed523e4 100644
--- a/helix-core/src/transaction.rs
+++ b/helix-core/src/transaction.rs
@@ -322,6 +322,14 @@ pub struct Transaction {
 }
 
 impl Transaction {
+    /// Create a new, empty transaction.
+    pub fn new(state: &mut State) -> Self {
+        Self {
+            changes: ChangeSet::new(&state.doc),
+            selection: None,
+        }
+    }
+
     /// Returns true if applied successfully.
     pub fn apply(&self, state: &mut State) -> bool {
         // apply changes to the document
diff --git a/helix-term/src/keymap.rs b/helix-term/src/keymap.rs
index 325157617..5611e1042 100644
--- a/helix-term/src/keymap.rs
+++ b/helix-term/src/keymap.rs
@@ -103,10 +103,18 @@ pub fn default() -> Keymap {
             code: KeyCode::Char('i'),
             modifiers: Modifiers::NONE
         } => commands::insert_mode as Command,
+        Key {
+            code: KeyCode::Char('I'),
+            modifiers: Modifiers::SHIFT,
+        } => commands::prepend_to_line as Command,
         Key {
             code: KeyCode::Char('a'),
             modifiers: Modifiers::NONE
         } => commands::append_mode as Command,
+        Key {
+            code: KeyCode::Char('A'),
+            modifiers: Modifiers::SHIFT,
+        } => commands::append_to_line as Command,
         Key {
             code: KeyCode::Char('o'),
             modifiers: Modifiers::NONE