Add :help command

book/src/generated/typable-cmd.md

@@ -73,3 +73,4 @@
 | `:pipe` | Pipe each selection to the shell command. |
 | `:pipe-to` | Pipe each selection to the shell command, ignoring output. |
 | `:run-shell-command`, `:sh` | Run a shell command |
+| `:help`, `:h` | Open documentation for a command or keybind. |

helix-term/src/commands/typed.rs

@@ -1808,6 +1808,155 @@ fn run_shell_command(
     Ok(())
 }
 
+fn help(cx: &mut compositor::Context, args: &[Cow<str>], event: PromptEvent) -> anyhow::Result<()> {
+    if event != PromptEvent::Validate {
+        return Ok(());
+    }
+
+    if args.is_empty() {
+        // TODO: Open a list of commands?
+        todo!()
+    }
+
+    if args[0] == "topics" {
+        let dir_path = helix_loader::runtime_dir().join("help/topics");
+
+        struct Topic(PathBuf);
+        impl crate::ui::menu::Item for Topic {
+            type Data = ();
+            fn label(&self, _data: &Self::Data) -> Spans {
+                self.0
+                    .file_stem()
+                    .and_then(|s| s.to_str())
+                    .map(From::from)
+                    .unwrap_or_default()
+            }
+        }
+
+        let entries: Vec<Topic> = std::fs::read_dir(&dir_path)
+            .map(|entries| {
+                entries
+                    .filter_map(|entry| {
+                        let entry = entry.ok()?;
+                        let path = entry.path();
+                        Some(path)
+                    })
+                    .map(Topic)
+                    .collect()
+            })
+            .unwrap_or_default();
+
+        cx.jobs.callback(async move {
+            let callback = job::Callback::EditorCompositor(Box::new(
+                move |_editor: &mut Editor, compositor: &mut Compositor| {
+                    let picker = FilePicker::new(
+                        entries,
+                        (),
+                        |cx, Topic(path), _action| {
+                            if let Err(e) =
+                                cx.editor
+                                    .open(path, Action::HorizontalSplit)
+                                    .and_then(|id| {
+                                        cx.editor
+                                            .document_mut(id)
+                                            .unwrap()
+                                            .set_path(None)
+                                            .map_err(Into::into)
+                                    })
+                            {
+                                cx.editor.set_error(e.to_string());
+                            }
+                        },
+                        |_editor, Topic(path)| Some((path.clone().into(), None)),
+                    );
+                    compositor.push(Box::new(picker));
+                },
+            ));
+
+            Ok(callback)
+        });
+
+        return Ok(());
+    }
+
+    let args_msg = args.join(" ");
+    let open_help =
+        move |help_dir: &str, command: &str, editor: &mut Editor| -> anyhow::Result<()> {
+            let mut path = helix_loader::runtime_dir();
+            path.push("help");
+            path.push(help_dir);
+            path.push(format!("{}.txt", command));
+
+            ensure!(path.is_file(), "No help available for '{}'", args_msg);
+            let id = editor.open(&path, Action::HorizontalSplit)?;
+            editor.document_mut(id).unwrap().set_path(None)?;
+            Ok(())
+        };
+
+    const STATIC_HELP_DIR: &str = "static-commands";
+    const TYPABLE_HELP_DIR: &str = "typable-commands";
+
+    let (help_dir, command): (&str, &str) = {
+        let arg = &args[0];
+        if let Some(command) = arg.strip_prefix(':').and_then(|arg| {
+            TYPABLE_COMMAND_LIST.iter().find_map(|command| {
+                (command.name == arg || command.aliases.iter().any(|alias| *alias == arg))
+                    .then(|| command.name)
+            })
+        }) {
+            (TYPABLE_HELP_DIR, command)
+        } else if MappableCommand::STATIC_COMMAND_LIST
+            .iter()
+            .any(|command| command.name() == arg)
+        {
+            (STATIC_HELP_DIR, arg)
+        } else {
+            let arg = arg.to_owned().into_owned();
+            let keys = arg
+                .parse::<KeyEvent>()
+                .map(|key| vec![key])
+                .or_else(|_| helix_view::input::parse_macro(&arg))?;
+
+            cx.jobs.callback(async move {
+                let callback = job::Callback::EditorCompositor(Box::new(
+                    move |editor: &mut Editor, compositor: &mut Compositor| {
+                        use crate::keymap::KeymapResult;
+                        let editor_view = compositor.find::<ui::EditorView>().unwrap();
+                        let mode = editor.mode;
+                        let keymaps = &mut editor_view.keymaps;
+                        let (keys, last_key) = (&keys[..keys.len() - 1], keys.last().unwrap());
+                        keys.iter().for_each(|key| {
+                            keymaps.get(mode, *key);
+                        });
+                        let result = keymaps.get(mode, *last_key);
+                        let res: anyhow::Result<(&str, &str)> = match &result {
+                            KeymapResult::Matched(command) => match command {
+                                MappableCommand::Static { name, .. } => Ok((STATIC_HELP_DIR, name)),
+                                MappableCommand::Typable { name, .. } => {
+                                    Ok((TYPABLE_HELP_DIR, name))
+                                }
+                            },
+                            KeymapResult::NotFound | KeymapResult::Cancelled(_) => {
+                                Err(anyhow!("No command found for '{}'", arg))
+                            }
+                            _ => todo!(),
+                        };
+                        if let Err(e) =
+                            res.and_then(|(help_dir, command)| open_help(help_dir, command, editor))
+                        {
+                            editor.set_error(e.to_string());
+                        }
+                    },
+                ));
+                Ok(callback)
+            });
+            return Ok(());
+        }
+    };
+
+    open_help(help_dir, command, cx.editor)
+}
+
 pub const TYPABLE_COMMAND_LIST: &[TypableCommand] = &[
         TypableCommand {
             name: "quit",
@@ -2323,6 +2472,13 @@ pub const TYPABLE_COMMAND_LIST: &[TypableCommand] = &[
             fun: run_shell_command,
             completer: Some(completers::directory),
         },
+        TypableCommand {
+            name: "help",
+            aliases: &["h"],
+            doc: "Open documentation for a command or keybind.",
+            fun: help,
+            completer: Some(completers::help),
+        },
     ];
 
 pub static TYPABLE_COMMAND_MAP: Lazy<HashMap<&'static str, &'static TypableCommand>> =

helix-term/src/ui/mod.rs

@@ -441,6 +441,50 @@ pub mod completers {
         })
     }
 
+    pub fn help(_editor: &Editor, input: &str) -> Vec<Completion> {
+        let static_cmds_path = helix_loader::runtime_dir().join("help/static-commands");
+        let typable_cmds_path = helix_loader::runtime_dir().join("help/typable-commands");
+        let mut items: Vec<String> = std::fs::read_dir(static_cmds_path)
+            .map(|entries| {
+                entries
+                    .filter_map(|entry| {
+                        let entry = entry.ok()?;
+                        let path = entry.path();
+                        (path.extension()? == "txt")
+                            .then(|| path.file_stem().unwrap().to_string_lossy().into_owned())
+                    })
+                    .chain(
+                        std::fs::read_dir(typable_cmds_path)
+                            .map(|entries| {
+                                entries.filter_map(|entry| {
+                                    let entry = entry.ok()?;
+                                    let path = entry.path();
+                                    (path.extension()? == "txt").then(|| {
+                                        format!(":{}", path.file_stem().unwrap().to_string_lossy())
+                                    })
+                                })
+                            })
+                            .into_iter()
+                            .flatten(),
+                    )
+                    .collect()
+            })
+            .unwrap_or_default();
+        items.push("topics".to_owned());
+
+        let matcher = Matcher::default();
+
+        let mut matches: Vec<_> = items
+            .into_iter()
+            .map(Cow::from)
+            .filter_map(|name| matcher.fuzzy_match(&name, input).map(|score| (name, score)))
+            .collect();
+
+        matches.sort_unstable_by_key(|(_file, score)| Reverse(*score));
+
+        matches.into_iter().map(|(name, _)| ((0..), name)).collect()
+    }
+
     #[derive(Copy, Clone, PartialEq, Eq)]
     enum FileMatch {
         /// Entry should be ignored

runtime/help/static-commands/append_mode.txt

@@ -0,0 +1,5 @@
+`append_mode`
+
+Enters Insert mode at the end of the selection.
+
+For information about Insert mode, see "Primary Modes".

runtime/help/static-commands/append_to_line.txt

@@ -0,0 +1,5 @@
+`append_to_line`
+
+Enters Insert mode at the end of the line.
+
+For information about Insert mode, see "Primary Modes".

runtime/help/static-commands/copy_selection_on_next_line.txt

@@ -0,0 +1,18 @@
+`copy_selection_on_next_line`
+
+Copies the current primary selection to the next line long enough to accomodate it.
+
+--- Examples ---
+
+The selection is copied from line 1 to line 2.
+┌───────────────────────────┐     ┌───────────────────────────┐
+│ This is text (on line 1]. │ --> │ This is text (on line 1]. │
+│ This is text on line 2.   │     │ This is text (on line 2]. │
+└───────────────────────────┘     └───────────────────────────┘
+
+The selection duplication skips line 2 because it is too short.
+┌──────────────────────────────────┐     ┌──────────────────────────────────┐
+│ This is a longer li(ne of t]ext. │     │ This is a longer li(ne of t]ext. │
+│ This is a shorter line.          │ --> │ This is a shorter line.          │
+│ This is another longer line.     │     │ This is another lon(ger lin]e.   │
+└──────────────────────────────────┘     └──────────────────────────────────┘

runtime/help/static-commands/copy_selection_on_prev_line.txt

@@ -0,0 +1,18 @@
+`copy_selection_on_prev_line`
+
+Copies the current primary selection to the first previous line long enough to accomodate it.
+
+--- Examples ---
+
+The selection is copied from line 2 to line 1.
+┌───────────────────────────┐     ┌───────────────────────────┐
+│ This is text on line 1.   │ --> │ This is text (on line 1]. │
+│ This is text (on line 2]. │     │ This is text (on line 2]. │
+└───────────────────────────┘     └───────────────────────────┘
+
+The selection duplication skips line 2 because it is too short.
+┌──────────────────────────────────┐     ┌──────────────────────────────────┐
+│ This is a longer line of text.   │     │ This is a longer li(ne of t]ext. │
+│ This is a shorter line.          │ --> │ This is a shorter line.          │
+│ This is another lon(ger lin]e.   │     │ This is another lon(ger lin]e.   │
+└──────────────────────────────────┘     └──────────────────────────────────┘

runtime/help/static-commands/extend_char_left.txt

@@ -0,0 +1,3 @@
+`extend_char_left`
+
+Extending version of `move_char_left`.

runtime/help/static-commands/extend_char_right.txt

@@ -0,0 +1,3 @@
+`extend_char_right`
+
+Extending version of `move_char_right`.

runtime/help/static-commands/extend_line_down.txt

@@ -0,0 +1,3 @@
+`extend_line_down`
+
+Extending version of `move_line_down`.

runtime/help/static-commands/extend_line_up.txt

@@ -0,0 +1,3 @@
+`extend_line_up`
+
+Extending version of `move_line_up`.

runtime/help/static-commands/extend_next_char.txt

@@ -0,0 +1,3 @@
+`extend_next_char`
+
+Extending version of `find_next_char`.

runtime/help/static-commands/extend_next_long_word_end.txt

@@ -0,0 +1,3 @@
+`extend_next_long_word_end`
+
+Extending version of `move_next_long_word_end`.

runtime/help/static-commands/extend_next_long_word_start.txt

@@ -0,0 +1,3 @@
+`extend_next_long_word_start`
+
+Extending version of `move_next_long_word_start`.

runtime/help/static-commands/extend_next_word_end.txt

@@ -0,0 +1,3 @@
+`extend_next_word_end`
+
+Extending version of `move_next_word_end`.

runtime/help/static-commands/extend_next_word_start.txt

@@ -0,0 +1,3 @@
+`extend_next_word_start`
+
+Extending version of `move_next_word_start`.

runtime/help/static-commands/extend_prev_char.txt

@@ -0,0 +1,3 @@
+`extend_prev_char`
+
+Extending version of `find_prev_char`.

runtime/help/static-commands/extend_prev_long_word_start.txt

@@ -0,0 +1,3 @@
+`extend_prev_long_word_start`
+
+Extending version of `move_prev_long_word_start`.

runtime/help/static-commands/extend_prev_word_start.txt

@@ -0,0 +1,3 @@
+`extend_prev_word_start`
+
+Extending version of `move_prev_word_start`.

runtime/help/static-commands/extend_till_char.txt

@@ -0,0 +1,3 @@
+`extend_till_char`
+
+Extending version of `find_till_char`.

runtime/help/static-commands/extend_till_prev_char.txt

@@ -0,0 +1,3 @@
+`extend_till_prev_char`
+
+Extending version of `till_prev_char`.

runtime/help/static-commands/find_next_char.txt

@@ -0,0 +1,22 @@
+`find_next_char`
+
+Waits for another keypress, then moves and
+selects forward, stopping at the first
+instance of the pressed key. Can take
+a count, which will cause it to stop
+at the nth instance of the keypress,
+rather than the first.
+
+--- Examples ---
+
+The cursor moves forward, stopping at 'c'
+and selecting everything along the way.
+┌───────────────────────┐  c  ┌───────────────────────┐
+│ This i[s] a sentence. │ --> │ This i(s a sentenc]e. │
+└───────────────────────┘     └───────────────────────┘
+
+The cursor is not stopped by line breaks.
+┌───────────────────────────┐     ┌────────────────────────────┐
+│ This is the fi[r]st line. │  Q  │ This is the fi(rst line.   │
+│ This second line has a Q. │ --> │ This second line has a Q]. │
+└───────────────────────────┘     └────────────────────────────┘

runtime/help/static-commands/find_prev_char.txt

@@ -0,0 +1,22 @@
+`find_prev_char`
+
+Waits for another keypress, then moves and
+selects backward, stopping at the first
+instance of the pressed key. Can take
+a count, which will cause it to stop
+at the nth instance of the keypress,
+rather than the first.
+
+--- Examples ---
+
+The cursor moves backward, stopping at 'h'
+and selecting everything along the way.
+┌───────────────────────┐  h  ┌───────────────────────┐
+│ This is a sent[e]nce. │ --> │ T[his is a sente)nce. │
+└───────────────────────┘     └───────────────────────┘
+
+The cursor is not stopped by line breaks.
+┌──────────────────────────────────┐     ┌───────────────────────────────────┐
+│ There is a Q in this first line. │  Q  │ There is a [Q in this first line. │
+│ This is the se[c]ond line.       │ --> │ This is the sec)ond line.         │
+└──────────────────────────────────┘     └───────────────────────────────────┘

runtime/help/static-commands/find_till_char.txt

@@ -0,0 +1,22 @@
+`find_till_char`
+
+Waits for another keypress, then moves and
+selects forward, stopping before the first
+instance of the pressed key. Can take
+a count, which will cause it to stop
+before the nth instance of the keypress,
+rather than the first.
+
+--- Examples ---
+
+The cursor moves forward, stopping before 'c'
+and selecting everything along the way.
+┌───────────────────────┐  c  ┌───────────────────────┐
+│ This i[s] a sentence. │ --> │ This i(s a senten]ce. │
+└───────────────────────┘     └───────────────────────┘
+
+The cursor is not stopped by line breaks.
+┌───────────────────────────┐     ┌────────────────────────────┐
+│ This is the fi[r]st line. │  Q  │ This is the fi(rst line.   │
+│ This second line has a Q. │ --> │ This second line has a ]Q. │
+└───────────────────────────┘     └────────────────────────────┘

runtime/help/static-commands/half_page_down.txt

@@ -0,0 +1,3 @@
+`half_page_down`
+
+Scrolls down by half of a screen.

runtime/help/static-commands/half_page_up.txt

@@ -0,0 +1,3 @@
+`half_page_up`
+
+Scrolls up by half of a screen.

runtime/help/static-commands/insert_mode.txt

@@ -0,0 +1,5 @@
+`insert_mode`
+
+Enters Insert mode at the start of the selection.
+
+For information about Insert mode, see "Primary Modes".

runtime/help/static-commands/move_char_left.txt

@@ -0,0 +1,4 @@
+`move_char_left`
+
+Moves all cursors 1 character left, removing
+any selections and wrapping across line breaks.

runtime/help/static-commands/move_char_right.txt

@@ -0,0 +1,4 @@
+`move_char_right`
+
+Moves all cursors 1 character right, removing
+any selections and wrapping across line breaks.

runtime/help/static-commands/move_line_down.txt

@@ -0,0 +1,15 @@
+`move_line_down`
+
+Moves all cursors 1 line down, removing any selections.
+Repeating this will remember the vertical position of the cursors,
+even when moving across shorter lines.
+
+--- Examples ---
+
+The cursor remembers its vertical position,
+even after moving across the shorter line.
+┌────────────────────────────┐     ┌────────────────────────────┐     ┌──────────────────────────────┐
+│ This is a longer l[i]ne.   │     │ This is a longer line.     │     │ This is a longer line.       │
+│ Shorter line.              │ --> │ Shorter line.[]            │ --> │ Shorter line.                │
+│ This is another long line. │     │ This is another long line. │     │ This is another lo[n]g line. │
+└────────────────────────────┘     └────────────────────────────┘     └──────────────────────────────┘

runtime/help/static-commands/move_line_up.txt

@@ -0,0 +1,15 @@
+`move_line_up`
+
+Moves all cursors 1 line up, removing any selections.
+Repeating this will remember the vertical position of the cursors,
+even when moving across shorter lines.
+
+--- Examples ---
+
+The cursor remembers its vertical position,
+even after moving across the shorter line.
+┌──────────────────────────────┐     ┌────────────────────────────┐     ┌────────────────────────────┐
+│ This is a longer line.       │     │ This is a longer line.     │     │ This is a longer l[i]ne.   │
+│ Shorter line.                │ --> │ Shorter line.[]            │ --> │ Shorter line.              │
+│ This is another lo[n]g line. │     │ This is another long line. │     │ This is another long line. │
+└──────────────────────────────┘     └────────────────────────────┘     └────────────────────────────┘

runtime/help/static-commands/move_next_long_word_end.txt

@@ -0,0 +1,17 @@
+`move_next_long_word_end`
+
+Moves and selects forward, stopping at
+the last character of the current WORD.
+
+For the difference between words and WORDS, see "Words vs. WORDS".
+
+--- Examples ---
+
+The cursor moves forward, stopping at the end of 'These-are'
+and selecting everything along the way.
+┌────────────────────┐     ┌────────────────────┐
+│ [T]hese-are WORDS. │ --> │ (These-are] WORDS. │
+└────────────────────┘     └────────────────────┘
+┌────────────────────┐     ┌────────────────────┐
+│ Th[e]se-are WORDS. │ --> │ Th(ese-are] WORDS. │
+└────────────────────┘     └────────────────────┘

runtime/help/static-commands/move_next_long_word_start.txt

@@ -0,0 +1,17 @@
+`move_next_long_word_start`
+
+Moves and selects forward, stopping before
+the first character of the next WORD.
+
+For the difference between words and WORDS, see "Words vs. WORDS".
+
+--- Examples ---
+
+The cursor moves forward, stopping before the start of 'WORDS'
+and selecting everything along the way.
+┌────────────────────┐     ┌────────────────────┐
+│ [T]hese-are WORDS. │ --> │ (These-are ]WORDS. │
+└────────────────────┘     └────────────────────┘
+┌────────────────────┐     ┌────────────────────┐
+│ Th[e]se-are WORDS. │ --> │ Th(ese-are ]WORDS. │
+└────────────────────┘     └────────────────────┘

runtime/help/static-commands/move_next_word_end.txt

@@ -0,0 +1,15 @@
+`move_next_word_end`
+
+Moves and selects forward, stopping at
+the last character of the current word.
+
+--- Examples ---
+
+The cursor moves forward, stopping at the end of 'These'
+and selecting everything along the way.
+┌────────────────────┐     ┌────────────────────┐
+│ [T]hese are words. │ --> │ (These] are words. │
+└────────────────────┘     └────────────────────┘
+┌────────────────────┐     ┌────────────────────┐
+│ Th[e]se are words. │ --> │ Th(ese] are words. │
+└────────────────────┘     └────────────────────┘

runtime/help/static-commands/move_next_word_start.txt

@@ -0,0 +1,15 @@
+`move_next_word_start`
+
+Moves and selects forward, stopping before
+the first character of the next word.
+
+--- Examples ---
+
+The cursor moves forward, stopping before the start of 'are'
+and selecting everything along the way.
+┌────────────────────┐     ┌────────────────────┐
+│ [T]hese are words. │ --> │ (These ]are words. │
+└────────────────────┘     └────────────────────┘
+┌────────────────────┐     ┌────────────────────┐
+│ Th[e]se are words. │ --> │ Th(ese ]are words. │
+└────────────────────┘     └────────────────────┘

runtime/help/static-commands/move_prev_long_word_start.txt

@@ -0,0 +1,20 @@
+`move_prev_long_word_start`
+
+Moves and selects backward, stopping at
+the first character of the previous WORD.
+
+For the difference between words and WORDS, see "Words vs. WORDS".
+
+--- Examples ---
+
+The cursor moves backwards, stopping at the start of 'These-are'
+and selecting everything along the way.
+┌────────────────────┐     ┌────────────────────┐
+│ These-are[ ]WORDS. │ --> │ [These-are )WORDS. │
+└────────────────────┘     └────────────────────┘
+┌────────────────────┐     ┌────────────────────┐
+│ These-are [W]ORDS. │ --> │ [These-are )WORDS. │
+└────────────────────┘     └────────────────────┘
+┌────────────────────┐     ┌────────────────────┐
+│ These-a[r]e WORDS. │ --> │ [These-ar)e WORDS. │
+└────────────────────┘     └────────────────────┘

runtime/help/static-commands/move_prev_word_start.txt

@@ -0,0 +1,18 @@
+`move_prev_word_start`
+
+Moves and selects backward, stopping at
+the first character of the previous word.
+
+--- Examples ---
+
+The cursor moves backwards, stopping at the start of 'These'
+and selecting everything along the way.
+┌────────────────────┐     ┌────────────────────┐
+│ These[ ]are words. │ --> │ [These )are words. │
+└────────────────────┘     └────────────────────┘
+┌────────────────────┐     ┌────────────────────┐
+│ These [a]re words. │ --> │ [These )are words. │
+└────────────────────┘     └────────────────────┘
+┌────────────────────┐     ┌────────────────────┐
+│ Th[e]se are words. │ --> │ [The)se are words. │
+└────────────────────┘     └────────────────────┘

runtime/help/static-commands/no_op.txt

@@ -0,0 +1,3 @@
+`no_op`
+
+Does nothing. Use this to disable default keybinds.

runtime/help/static-commands/page_down.txt

@@ -0,0 +1,3 @@
+`page_down`
+
+Scrolls down by one screen.

runtime/help/static-commands/page_up.txt

@@ -0,0 +1,3 @@
+`page_up`
+
+Scrolls up by one screen.

runtime/help/static-commands/prepend_to_line.txt

@@ -0,0 +1,5 @@
+`prepend_to_line`
+
+Enters Insert mode before the first non-whitespace character in the line.
+
+For information about Insert mode, see "Primary Modes".

runtime/help/static-commands/replace.txt

@@ -0,0 +1,21 @@
+`replace`
+
+Waits for another keypress, then replaces all
+selected characters with the pressed key.
+
+--- Examples ---
+
+'a' is replaced with 'e'.
+┌──────────────────────────┐  e  ┌──────────────────────────┐
+│ Do this, th[a]n do that. │ --> │ Do this, th[e]n do that. │
+└──────────────────────────┘     └──────────────────────────┘
+
+All instances of ',' are replaced with '.'.
+┌──────────────────────────────┐  .  ┌──────────────────────────────┐
+│ This sentence continues(,,,] │ --> │ This sentence continues(...] │
+└──────────────────────────────┘     └──────────────────────────────┘
+
+All instances of 'a' are replaced with 'e'.
+┌──────────────────────────────────┐  e  ┌──────────────────────────────────┐
+│ 1, th[a]n 2, th[a]n 3, th[a]n 4. │ --> │ 1, th[e]n 2, th[e]n 3, th[e]n 4. │
+└──────────────────────────────────┘     └──────────────────────────────────┘

runtime/help/static-commands/select_all.txt

@@ -0,0 +1,3 @@
+`select_all`
+
+Selects the entire buffer.

runtime/help/static-commands/switch_case.txt

@@ -0,0 +1,13 @@
+`switch_case`
+
+Toggles the case of all selected letters.
+
+--- Examples ---
+
+┌───────────────────────┐     ┌───────────────────────┐
+│ [t]his is a sentence. │ --> │ [T]his is a sentence. │
+└───────────────────────┘     └───────────────────────┘
+
+┌───────────────────────┐     ┌───────────────────────┐
+│ (tHIS] is a sentence. │ --> │ (This] is a sentence. │
+└───────────────────────┘     └───────────────────────┘

runtime/help/static-commands/switch_to_lowercase.txt

@@ -0,0 +1,9 @@
+`switch_to_lowercase`
+
+Changes all selected letters to lowercase.
+
+--- Examples ---
+
+┌──────────────────────────────────┐     ┌──────────────────────────────────┐
+│ This (wOrD] should be lowercase. │ --> │ This (word] should be lowercase. │
+└──────────────────────────────────┘     └──────────────────────────────────┘

runtime/help/static-commands/switch_to_uppercase.txt

@@ -0,0 +1,9 @@
+`switch_to_uppercase`
+
+Changes all selected letters to uppercase.
+
+--- Examples ---
+
+┌──────────────────────────────────┐     ┌──────────────────────────────────┐
+│ This (wOrD] should be uppercase. │ --> │ This (WORD] should be uppercase. │
+└──────────────────────────────────┘     └──────────────────────────────────┘

runtime/help/static-commands/till_prev_char.txt

@@ -0,0 +1,22 @@
+`till_prev_char`
+
+Waits for another keypress, then moves and
+selects backward, stopping before the first
+instance of the pressed key. Can take
+a count, which will cause it to stop
+before the nth instance of the keypress,
+rather than the first.
+
+--- Examples ---
+
+The cursor moves backward, stopping before 'h'
+and selecting everything along the way.
+┌───────────────────────┐  h  ┌───────────────────────┐
+│ This is a sent[e]nce. │ --> │ Th[is is a sente)nce. │
+└───────────────────────┘     └───────────────────────┘
+
+The cursor is not stopped by line breaks.
+┌──────────────────────────────────┐     ┌───────────────────────────────────┐
+│ There is a Q in this first line. │  Q  │ There is a Q[ in this first line. │
+│ This is the se[c]ond line.       │ --> │ This is the sec)ond line.         │
+└──────────────────────────────────┘     └───────────────────────────────────┘

runtime/help/topics/Primary Modes.txt

@@ -0,0 +1,21 @@
+Primary Modes
+
+Helix is a modal editor, and has two primary "modes" of operation.
+
+Normal mode, which is the mode you start in by default, and which
+you will likely spend a substantial amount of time in, is the main
+mode used for text editing operations.
+
+Insert mode, which can be entered in numerous ways — such as by
+pressing i — is used for typing text.
+
+A third mode, called "Select" or "Extend" mode, is essentially a
+subset of Normal mode, where moving cursors leaves selection
+anchors in place — useful for making modifications to existing
+selections. Select mode can be toggled by pressing v.
+
+You can see which of these three modes you are currently in by
+looking at the left side of the statusline. It will display:
+  NOR — Normal mode
+  INS — Insert mode
+  SEL — Select mode

runtime/help/topics/Words vs. WORDS.txt

@@ -0,0 +1,19 @@
+Words vs. WORDS
+
+Words and WORDS are two very similar types of text objects. A word
+is a string of "word" characters, which include letters, numbers,
+and underscores. A WORD, on the other hand, is any string of
+non-whitespace characters.
+
+In the example below, the words are underlined by 'w', and the
+WORDS are underlined by 'W'.
+
+  This "stuff" is not-so difficult!
+  ---------------------------------
+  wwww  wwwww  ww www ww wwwwwwwww
+  WWWW WWWWWWW WW WWWWWW WWWWWWWWWW
+
+As is visible in the example, the words do not include any of the
+non-alphanumeric punctuation, while the WORDS do include the
+quotes, hyphen, and exclamation point. Also notice that 'not-so'
+contains two words, but only one WORD.

runtime/help/typable-commands/buffer-close!.txt

@@ -0,0 +1,6 @@
+`:buffer-close!`
+
+Aliases: `:bc!`, `:bclose!`
+
+Closes the current buffer, discarding any
+unsaved changes to the buffer.

runtime/help/typable-commands/buffer-close.txt

@@ -0,0 +1,6 @@
+`:buffer-close`
+
+Aliases: `:bc`, `:bclose`
+
+Closes the current buffer, failing if the buffer
+has unsaved changes.

runtime/help/typable-commands/new.txt

@@ -0,0 +1,6 @@
+`:new`
+
+Aliases: `:n`
+
+Creates and switches to a new scratch buffer. This
+buffer will not be associated with any file path.

runtime/help/typable-commands/open.txt

@@ -0,0 +1,8 @@
+`:open <path>`
+
+Aliases: `:o`
+
+If <path> exists, opens the file at <path>.
+If <path> does not exist, creates a new buffer
+and associates it with <path>. Note that this
+does not automatically save the created buffer.

runtime/help/typable-commands/quit!.txt

@@ -0,0 +1,7 @@
+`:quit!`
+
+Aliases: `:q!`
+
+Closes the current view, exiting the editor if it is
+the last view. If this would exit the editor, unsaved
+changes are discarded.

runtime/help/typable-commands/quit-all!.txt

@@ -0,0 +1,6 @@
+`:quit-all!`
+
+Aliases: `:qa!`
+
+Closes all views, exiting the editor. This will
+discard any unsaved changes.

runtime/help/typable-commands/quit-all.txt

@@ -0,0 +1,6 @@
+`:quit-all`
+
+Aliases: `:qa`
+
+Closes all views, exiting the editor. This will
+fail if there are any unsaved changes.

runtime/help/typable-commands/quit.txt

@@ -0,0 +1,7 @@
+`:quit`
+
+Aliases: `:q`
+
+Closes the current view, exiting the editor if it is
+the last view. This will fail if it would exit the
+editor while there are unsaved changes.

runtime/help/typable-commands/write-all.txt

@@ -0,0 +1,7 @@
+`:write-all`
+
+Aliases: `:wa`
+
+Writes (saves) all unsaved buffers to disk.
+Scratch buffers (without associated paths)
+will not be saved.

runtime/help/typable-commands/write-quit!.txt

@@ -0,0 +1,9 @@
+`:write-quit! [path]`
+
+Aliases: `:wq!`, `:x!`
+
+Writes (saves) the buffer to disk, then
+closes the view, discarding unsaved changes
+if this would exit the editor.
+Identical to `:write [path]` followed by `:quit!`.
+See those commands for more info.

runtime/help/typable-commands/write-quit-all!.txt

@@ -0,0 +1,10 @@
+`:write-quit-all!`
+
+Aliases: `:wqa!`, `:xa!`
+
+Writes (saves) all unsaved buffers to disk, then
+closes all views, exiting the editor.
+Scratch buffers (without associated paths) will
+not be saved, and will be discarded when the
+editor exits.
+Identical to `:write-all` followed by `:quit-all!`.

runtime/help/typable-commands/write-quit-all.txt

@@ -0,0 +1,10 @@
+`:write-quit-all`
+
+Aliases: `:wqa`, `:xa`
+
+Writes (saves) all unsaved buffers to disk, then
+closes all views, exiting the editor.
+Scratch buffers (without associated paths) will
+not be saved, and exiting the editor will fail
+if there are any such buffers open.
+Identical to `:write-all` followed by `:quit-all`.

runtime/help/typable-commands/write-quit.txt

@@ -0,0 +1,8 @@
+`:write-quit [path]`
+
+Aliases: `:wq`, `:x`
+
+Writes (saves) the buffer to disk, then
+closes the view.
+Identical to `:write [path]` followed by `:quit`.
+See those commands for more info.

runtime/help/typable-commands/write.txt

@@ -0,0 +1,9 @@
+`:write [path]`
+
+Aliases: `:w`
+
+Writes (saves) the buffer to disk.
+If [path] is supplied, that path is written to.
+If the buffer is a scratch buffer, meaning it
+is not already bound to a file path, [path]
+becomes required for this command to succeed.