Initial public release of Warp.

Repo-Sync-Origin: warpdotdev/warp-internal@12af1d983b

crates/vim/src/find_char.rs

@@ -0,0 +1,95 @@
+use crate::vim::{Direction, FindCharDestination, FindCharMotion};
+use warpui::text::TextBuffer;
+
+/// Find the destination column for Vim's f/F/t/T motions on a single line.
+///
+/// This search has four variants based on the direction of search
+/// and where the cursor is expected to end up relative to the target character.
+/// When moving the cursor to the character before the target,
+/// ve must start searching further away from the cursor to
+/// ensure we don't re-match the previous target.
+///
+/// Given the string `abcdefgh` and a cursor on `d`,
+/// here's where each type of search starts looking for the target character
+/// when repeated:
+///
+/// 0 1 2 3 4 5 6 7
+/// a b c d e f g h
+/// __F_| ^ |__f___ (also t/T initially)
+/// T_|       |__t_ (when repeated)
+///
+/// F: (Backward, at target) starts right at the cursor.
+/// T: (Backward, before target)` starts one before the cursor when repeated.
+/// f: (Forward, at target)` starts one after the cursor.
+/// t: (Forward, before target)` starts two after the cursor when repeated.
+///
+/// Returns Some(new_column) if the target is found on the line based on the parameters; otherwise None.
+pub fn vim_find_char_on_line(
+    line: &str,
+    current_column: usize,
+    motion: &FindCharMotion,
+    occurrence_count: u32,
+    keep_selection: bool,
+) -> Option<usize> {
+    let FindCharMotion {
+        direction,
+        destination,
+        is_repetition,
+        c,
+    } = motion;
+
+    let search_start_column = match (direction, destination, is_repetition) {
+        (Direction::Backward, FindCharDestination::AtChar, _)
+        | (Direction::Backward, FindCharDestination::BeforeChar, false) => current_column,
+        (Direction::Backward, FindCharDestination::BeforeChar, true) => {
+            current_column.saturating_sub(1)
+        }
+
+        // When moving forward, skip the current character under the cursor.
+        (Direction::Forward, FindCharDestination::AtChar, _)
+        | (Direction::Forward, FindCharDestination::BeforeChar, false) => current_column + 1,
+        (Direction::Forward, FindCharDestination::BeforeChar, true) => current_column + 2,
+    };
+
+    let found_char = match direction {
+        Direction::Backward => {
+            line.chars_rev_at(search_start_column.into())
+                .ok()
+                .and_then(|iter| {
+                    iter.enumerate()
+                        .filter(|(_, ch)| ch == c)
+                        .nth(occurrence_count.saturating_sub(1) as usize)
+                })
+        }
+        Direction::Forward => line
+            .chars_at(search_start_column.into())
+            .ok()
+            .and_then(|iter| {
+                iter.enumerate()
+                    .filter(|(_, ch)| ch == c)
+                    .nth(occurrence_count.saturating_sub(1) as usize)
+            }),
+    };
+
+    if let Some((i, _)) = found_char {
+        let move_distance = match (destination, is_repetition) {
+            (FindCharDestination::AtChar, _) | (FindCharDestination::BeforeChar, true) => i + 1,
+            (FindCharDestination::BeforeChar, false) => i,
+        };
+
+        let mut new_column = match direction {
+            Direction::Backward => current_column.saturating_sub(move_distance),
+            Direction::Forward => current_column + move_distance,
+        };
+
+        // When moving to the right and keeping selection, we include the matched character,
+        // so we have to add 1 in this particular case.
+        if keep_selection && direction == &Direction::Forward {
+            new_column += 1;
+        }
+
+        Some(new_column)
+    } else {
+        None
+    }
+}

crates/vim/src/lib.rs

@@ -0,0 +1,17 @@
+mod matching_brackets;
+pub use matching_brackets::vim_find_matching_bracket;
+
+mod paragraph_iterator;
+pub use paragraph_iterator::{find_next_paragraph_end, find_previous_paragraph_start};
+pub mod register;
+
+mod text_objects;
+pub use text_objects::*;
+
+mod word_iterator;
+pub use word_iterator::vim_word_iterator_from_offset;
+
+mod find_char;
+pub use find_char::vim_find_char_on_line;
+
+pub mod vim;

crates/vim/src/matching_brackets.rs

@@ -0,0 +1,50 @@
+use itertools::Itertools;
+use string_offset::CharOffset;
+use warpui::text::TextBuffer;
+
+use crate::vim::{BracketChar, BracketEnd};
+
+/// This method looks for the bracket that complements/pairs with the passed in BracketChar,
+/// starting the search at the passed in offset.
+pub fn vim_find_matching_bracket<'a, T, C>(
+    buffer: &'a T,
+    bracket_char: &BracketChar,
+    offset: C,
+) -> Option<CharOffset>
+where
+    T: TextBuffer + ?Sized + 'a,
+    C: Into<CharOffset>,
+{
+    let offset = offset.into();
+
+    // If we're matching for an opening bracket, search forward, and vice versa.
+    let mut iter: Box<dyn Iterator<Item = char>> = match bracket_char.end {
+        BracketEnd::Opening => Box::new(buffer.chars_at(offset + 1).ok()?),
+        BracketEnd::Closing => Box::new(buffer.chars_rev_at(offset).ok()?),
+    };
+
+    // If we encounter more instances of the same bracket, i.e. we're matching "(" and we pass by
+    // another "(", we must first match each additional "(" we encounter. Keep a count of those in
+    // this "depth" variable.
+    let mut depth: u32 = 0;
+    let (i, _) = iter.find_position(|c| {
+        if bracket_char.is_char(*c) {
+            depth += 1;
+        } else if bracket_char.complements(*c) {
+            if depth == 0 {
+                return true;
+            } else {
+                depth -= 1;
+            }
+        }
+        false
+    })?;
+    match bracket_char.end {
+        BracketEnd::Opening => Some(offset + i + 1),
+        BracketEnd::Closing => Some(offset - i - 1),
+    }
+}
+
+#[cfg(test)]
+#[path = "matching_brackets_tests.rs"]
+mod tests;

crates/vim/src/matching_brackets_tests.rs

@@ -0,0 +1,63 @@
+use super::*;
+
+impl BracketChar {
+    fn from_char(c: char) -> Self {
+        Self::try_from(c).unwrap_or_else(|_| panic!("invalid bracket char: {c}"))
+    }
+}
+
+#[test]
+fn test_vim_find_matching_bracket() {
+    assert_eq!(
+        vim_find_matching_bracket("", &BracketChar::from_char('('), 0),
+        None,
+    );
+    assert_eq!(
+        vim_find_matching_bracket("foo(bar)baz", &BracketChar::from_char('('), 3),
+        Some(7.into())
+    );
+    assert_eq!(
+        vim_find_matching_bracket("foo(bar)baz", &BracketChar::from_char(')'), 7),
+        Some(3.into())
+    );
+    assert_eq!(
+        vim_find_matching_bracket("foo(bar)baz", &BracketChar::from_char('('), 8),
+        None
+    );
+    assert_eq!(
+        vim_find_matching_bracket("foo[bar]baz", &BracketChar::from_char('('), 3),
+        None
+    );
+    assert_eq!(
+        vim_find_matching_bracket("foo(bar(hello) world)baz", &BracketChar::from_char('('), 3),
+        Some(20.into())
+    );
+    assert_eq!(
+        vim_find_matching_bracket("foo(bar(hello) world)baz", &BracketChar::from_char(')'), 20),
+        Some(3.into())
+    );
+    assert_eq!(
+        vim_find_matching_bracket(
+            "foo(bar(h[(])llo) world)baz",
+            &BracketChar::from_char('('),
+            3
+        ),
+        Some(23.into())
+    );
+    assert_eq!(
+        vim_find_matching_bracket(
+            "function foo() {\necho hello world\necho hi\n}\nfoo",
+            &BracketChar::from_char('{'),
+            15
+        ),
+        Some(42.into())
+    );
+    assert_eq!(
+        vim_find_matching_bracket(
+            "function foo() {\necho hello world\necho hi\n}\nfoo",
+            &BracketChar::from_char('}'),
+            42
+        ),
+        Some(15.into())
+    );
+}

crates/vim/src/paragraph_iterator.rs

@@ -0,0 +1,66 @@
+use string_offset::CharOffset;
+use warpui::text::TextBuffer;
+
+/// Returns the offset of the first newline above a paragraph start before the current position.
+pub fn find_previous_paragraph_start<'a, T, C>(buffer: &'a T, offset: C) -> Option<CharOffset>
+where
+    T: TextBuffer + ?Sized + 'a,
+    C: Into<CharOffset>,
+{
+    let offset = offset.into();
+
+    // Skip newlines between the current position and prior paragraph end
+    let iter = buffer
+        .chars_rev_at(offset + 1) // chars_rev_at doesn't include the current offset
+        .ok()?
+        .enumerate()
+        .skip_while(|(_, c)| *c == '\n');
+
+    // Scan from current position backward until we find two newlines in a row
+    let mut prev_was_newline = false;
+    for (curr, c) in iter {
+        if c == '\n' {
+            if prev_was_newline {
+                return Some(offset + 1 - curr); // + 1 because the enumerate is shifted above
+            }
+            prev_was_newline = true;
+        } else {
+            prev_was_newline = false;
+        }
+    }
+
+    None
+}
+/// Returns the offset of the first newline below a paragraph end after the current position.
+pub fn find_next_paragraph_end<'a, T, C>(buffer: &'a T, offset: C) -> Option<CharOffset>
+where
+    T: TextBuffer + ?Sized + 'a,
+    C: Into<CharOffset>,
+{
+    let offset = offset.into();
+
+    // Skip newlines between the current position and next paragraph start
+    let iter = buffer
+        .chars_at(offset)
+        .ok()?
+        .enumerate()
+        .skip_while(|(_, c)| *c == '\n');
+
+    // Scan from current position forward until we find two newlines in a row
+    let mut prev_was_newline = false;
+    for (curr, c) in iter {
+        if c == '\n' {
+            if prev_was_newline {
+                return Some(offset + curr);
+            }
+            prev_was_newline = true;
+        } else {
+            prev_was_newline = false;
+        }
+    }
+
+    None
+}
+#[cfg(test)]
+#[path = "paragraph_iterator_tests.rs"]
+mod tests;

crates/vim/src/paragraph_iterator_tests.rs

@@ -0,0 +1,108 @@
+use super::*;
+
+#[test]
+fn test_single_paragraph_returns_none_both_directions() {
+    // Single paragraph: no double-newline separator anywhere
+    let text = "p1 line1\np1 line2\np1 line3";
+    let pos = text.find("line2").unwrap();
+
+    assert_eq!(find_previous_paragraph_start(text, pos), None);
+    assert_eq!(find_next_paragraph_end(text, pos), None);
+}
+
+#[test]
+fn test_single_paragraph_surrounded_returns_prev_and_next() {
+    // Single paragraph: no double-newline separator anywhere
+    let text = "\n\n\np1 line1\np1 line2\np1 line3\n\n\n";
+    let pos = text.find("line2").unwrap();
+
+    // The first empty line after the end of the paragraph (the second newline character)
+    let goal_end = text.find("line3").unwrap() + "line3".len() + 1;
+
+    assert_eq!(find_previous_paragraph_start(text, pos), Some(2.into()));
+    assert_eq!(find_next_paragraph_end(text, pos), Some(goal_end.into()));
+}
+
+#[test]
+fn test_next_none_in_last_paragraph_previous_goes_up() {
+    // Two paragraphs separated by one blank line (double newline)
+    let text = "p1\n\np2";
+    let pos_in_p2 = text.find("p2").unwrap();
+
+    // previous should find the boundary before p2: index of the second newline in the pair
+    // for both cursor positioning on the `p` and `2`
+    assert_eq!(
+        find_previous_paragraph_start(text, pos_in_p2),
+        Some((pos_in_p2 - 1).into())
+    );
+    assert_eq!(
+        find_previous_paragraph_start(text, pos_in_p2 + 1),
+        Some((pos_in_p2 - 1).into())
+    );
+    // next should find nothing after the last paragraph
+    assert_eq!(find_next_paragraph_end(text, pos_in_p2), None);
+}
+
+#[test]
+fn test_previous_none_in_first_paragraph_next_goes_down() {
+    let text = "p1\n\np2";
+    let pos_in_p1 = text.find("p1").unwrap();
+
+    // previous should find nothing before the first paragraph
+    assert_eq!(find_previous_paragraph_start(text, pos_in_p1), None);
+    // next should find the boundary after p1: index of the second newline in the pair
+    // for both cursor positioning on the `p` and `1`
+    assert_eq!(
+        find_next_paragraph_end(text, pos_in_p1),
+        Some((pos_in_p1 + "p1".len() + 1).into())
+    );
+    assert_eq!(
+        find_next_paragraph_end(text, pos_in_p1 + 1),
+        Some((pos_in_p1 + "p1".len() + 1).into())
+    );
+}
+
+#[test]
+fn test_three_paragraphs_lots_of_newlines_middle_para() {
+    // Three paragraphs, separated by four newlines each
+    let text = "p1\n\n\n\n".to_string() + "p2\n\n\n\n" + "p3";
+    let pos_in_p2 = text.find("p2").unwrap();
+
+    assert_eq!(
+        find_previous_paragraph_start(text.as_str(), pos_in_p2),
+        Some((pos_in_p2 - 1).into())
+    );
+    assert_eq!(
+        find_next_paragraph_end(text.as_str(), pos_in_p2),
+        Some((pos_in_p2 + "p2".len() + 1).into())
+    );
+}
+
+#[test]
+fn test_cursor_in_middle_of_newline_patch_quad_runs() {
+    // Lots of newlines between paras, but cursor starts in the middle of the newlines
+    let text = "p1\n\n\n\n\n\n".to_string() + "p2\n\n\n\n\n\n" + "p3";
+    let pos_between_p1_p2 = "p1".len() + 3;
+    let pos_p2 = text.find("p2").unwrap();
+    let pos_between_p2_p3 = pos_p2 + "p2".len() + 3;
+
+    // Place cursor amongst newlines between p1 and p2
+    assert_eq!(
+        find_previous_paragraph_start(text.as_str(), pos_between_p1_p2),
+        None
+    );
+    assert_eq!(
+        find_next_paragraph_end(text.as_str(), pos_between_p1_p2),
+        Some((pos_p2 + "p2".len() + 1).into())
+    );
+
+    // Place cursor amongst newlines between p2 and p3
+    assert_eq!(
+        find_previous_paragraph_start(text.as_str(), pos_between_p2_p3),
+        Some((pos_p2 - 1).into())
+    );
+    assert_eq!(
+        find_next_paragraph_end(text.as_str(), pos_between_p2_p3),
+        None
+    );
+}

crates/vim/src/register.rs

@@ -0,0 +1,8 @@
+/// In Vim, see ":help quote_".
+/// The black hole register can be written to but it always reads as empty.
+pub const BLACK_HOLE_REGISTER: char = '_';
+
+/// The registers we currently support.
+pub fn valid_register_name(c: char) -> bool {
+    matches!(c, 'a'..='z' | 'A'..='Z' | '+' | '*' | '"')
+}

crates/vim/src/text_objects/block.rs

@@ -0,0 +1,132 @@
+//! This module is for "block objects" i.e. text objects delimited by brackets/parentheses.
+
+use std::ops::Range;
+
+use itertools::Itertools;
+use string_offset::CharOffset;
+use warpui::text::TextBuffer;
+
+use crate::{
+    vim::{BracketChar, BracketEnd, BracketType},
+    vim_find_matching_bracket,
+};
+
+/// Vim's block-based text objects, e.g. `di{`. This includes a string of text enclosed by any pair
+/// of [`BracketType`], not including the brackets themselves.
+/// See https://vimdoc.sourceforge.net/htmldoc/motion.html#ib
+/// or enter ":help i{" in Vim.
+///
+/// There may be whitespace in within the brackets which is also not included. If the closing
+/// bracket is on a different line then the opening bracket, and there is only whitespace between
+/// the closing bracket and the newline preceding it, all that space plus the newline are _not_
+/// included in the text object. (AFAIK this is not documented.) We can refer to that space as
+/// "trailing padding". Furthermore, the `c` and `d` commands differ in how they respect "leading
+/// padding", i.e. the whitespace plus newline after the opening bracket, in that `d` will delete
+/// the leading padding but `c` will not. The `preserve_leading_padding` parameter controls this.
+///
+/// Returns None when the buffer is empty, the offset is out of bounds, or there is no matching
+/// pair of brackets of the type we're looking for around the cursor.
+pub fn vim_inner_block<T, C>(
+    buffer: &T,
+    offset: C,
+    bracket_type: BracketType,
+    preserve_leading_padding: bool,
+) -> Option<Range<CharOffset>>
+where
+    T: TextBuffer + ?Sized,
+    C: Into<CharOffset>,
+{
+    let block_range = vim_a_block(buffer, offset, bracket_type)?;
+    let (mut block_start, mut block_end) = (block_range.start, block_range.end);
+
+    // Move bounds by 1 to remove the brackets, though we may need to trim any trailing or leading
+    // padding.
+    block_start += 1;
+    block_end -= 1;
+
+    // First, check if we need to remove trailing padding from the range.
+    if let Some((i, _)) = buffer
+        .chars_rev_at(block_end)
+        .ok()?
+        .take_while(|c| c.is_whitespace())
+        .find_position(|c| *c == '\n')
+    {
+        block_end -= i + 1;
+    }
+
+    // Finally, if we're doing a command that preserves leading padding, e.g. `c`, check if we need
+    // to remove that from the range.
+    if preserve_leading_padding {
+        if let Some((i, _)) = buffer
+            .chars_at(block_start)
+            .ok()?
+            .take_while(|c| c.is_whitespace())
+            .find_position(|c| *c == '\n')
+        {
+            block_start += i + 1;
+        }
+    }
+
+    Some(block_start..block_end)
+}
+
+/// Vim's block-based text objects, e.g. `da{`. This includes a string of text enclosed by any pair
+/// of [`BracketType`], including the brackets themselves.
+/// See https://vimdoc.sourceforge.net/htmldoc/motion.html#ab
+/// or enter ":help a{" in Vim.
+///
+/// Returns None when the buffer is empty, the offset is out of bounds, or there is no matching
+/// pair of brackets of the type we're looking for around the cursor.
+pub fn vim_a_block<T, C>(
+    buffer: &T,
+    offset: C,
+    bracket_type: BracketType,
+) -> Option<Range<CharOffset>>
+where
+    T: TextBuffer + ?Sized,
+    C: Into<CharOffset>,
+{
+    let offset = offset.into();
+    // If the buffer is empty, return early.
+    let c = buffer.chars_at(offset).ok()?.next()?;
+
+    // Check if the cursor is already on a bracket of the type we're looking for.
+    match BracketChar::try_from(c) {
+        // If it is, just call [`vim_find_matching_bracket`] for the other bracket.
+        Ok(bracket) if bracket.kind == bracket_type => {
+            let other_offset = vim_find_matching_bracket(buffer, &bracket, offset)?;
+            // We may have just moved backwards or forwards. Make sure the smaller offset comes
+            // first in the range bounds.
+            let (start_offset, end_offset) = if other_offset > offset {
+                (offset, other_offset)
+            } else {
+                (other_offset, offset)
+            };
+            Some(start_offset..end_offset + 1)
+        }
+        // If not, perform the search in both directions.
+        _ => {
+            let end_offset = vim_find_matching_bracket(
+                buffer,
+                &BracketChar {
+                    end: BracketEnd::Opening,
+                    kind: bracket_type,
+                },
+                offset,
+            )?;
+            let start_offset = vim_find_matching_bracket(
+                buffer,
+                &BracketChar {
+                    end: BracketEnd::Closing,
+                    kind: bracket_type,
+                },
+                end_offset,
+            )?;
+            Some(start_offset..end_offset + 1)
+        }
+    }
+}
+
+#[cfg(test)]
+#[path = "block_tests.rs"]
+mod tests;

crates/vim/src/text_objects/block_tests.rs

@@ -0,0 +1,147 @@
+use super::*;
+use unindent::Unindent;
+
+const BLOCK: &str = "match BracketChar::try_from(c) {
+        Ok(bracket) => todo!(),
+        Err(_) => {
+            let end_offset = vim_find_matching_bracket(
+                buffer,
+                BracketChar {
+                    end: BracketEnd::Opening,
+                    kind: bracket_kind,
+                },
+                offset,
+            )?;
+            let start_offset = vim_find_matching_bracket(
+                buffer,
+                BracketChar {
+                    end: BracketEnd::Closing,
+                    kind: bracket_kind,
+                },
+                end_offset,
+            )?;
+            Some(start_offset..end_offset)
+        }
+    }";
+
+#[test]
+fn test_vim_a_block() {
+    let block = BLOCK.unindent();
+    for i in 27..=29 {
+        assert_eq!(
+            vim_a_block(block.as_str(), i, BracketType::Parenthesis),
+            Some(27.into()..30.into())
+        );
+    }
+    for i in (31..=74).chain(573..=574) {
+        assert_eq!(
+            vim_a_block(block.as_str(), i, BracketType::CurlyBrace),
+            Some(31.into()..575.into())
+        );
+    }
+    for i in (75..=172).chain(266..=397).chain(491..=572) {
+        assert_eq!(
+            vim_a_block(block.as_str(), i, BracketType::CurlyBrace),
+            Some(75.into()..573.into())
+        );
+    }
+    for i in 173..=265 {
+        assert_eq!(
+            vim_a_block(block.as_str(), i, BracketType::CurlyBrace),
+            Some(173.into()..266.into())
+        );
+    }
+    for i in 398..=490 {
+        assert_eq!(
+            vim_a_block(block.as_str(), i, BracketType::CurlyBrace),
+            Some(398.into()..491.into())
+        );
+    }
+    for i in 39..=47 {
+        assert_eq!(
+            vim_a_block(block.as_str(), i, BracketType::Parenthesis),
+            Some(39.into()..48.into())
+        );
+    }
+    for i in 57..=58 {
+        assert_eq!(
+            vim_a_block(block.as_str(), i, BracketType::Parenthesis),
+            Some(57.into()..59.into())
+        );
+    }
+}
+
+#[test]
+fn test_vim_inner_block() {
+    let block = BLOCK.unindent();
+    for i in 27..=29 {
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::Parenthesis, false),
+            Some(28.into()..29.into())
+        );
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::Parenthesis, true),
+            Some(28.into()..29.into())
+        );
+    }
+    for i in (31..=74).chain(573..=574) {
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::CurlyBrace, false),
+            Some(32.into()..573.into())
+        );
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::CurlyBrace, true),
+            Some(33.into()..573.into())
+        );
+    }
+    for i in (75..=172).chain(266..=397).chain(491..=572) {
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::CurlyBrace, false),
+            Some(76.into()..567.into())
+        );
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::CurlyBrace, true),
+            Some(77.into()..567.into())
+        );
+    }
+    for i in 173..=265 {
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::CurlyBrace, false),
+            Some(174.into()..252.into())
+        );
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::CurlyBrace, true),
+            Some(175.into()..252.into())
+        );
+    }
+    for i in 398..=490 {
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::CurlyBrace, false),
+            Some(399.into()..477.into())
+        );
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::CurlyBrace, true),
+            Some(400.into()..477.into())
+        );
+    }
+    for i in 39..=47 {
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::Parenthesis, false),
+            Some(40.into()..47.into())
+        );
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::Parenthesis, true),
+            Some(40.into()..47.into())
+        );
+    }
+    for i in 57..=58 {
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::Parenthesis, false),
+            Some(58.into()..58.into())
+        );
+        assert_eq!(
+            vim_inner_block(block.as_str(), i, BracketType::Parenthesis, true),
+            Some(58.into()..58.into())
+        );
+    }
+}

crates/vim/src/text_objects/mod.rs

@@ -0,0 +1,13 @@
+//! This module is for text-objects, e.g. `diw` and the like.
+//!
+//! See https://vimdoc.sourceforge.net/htmldoc/motion.html#text-objects
+//! or enter ":help text-objects" in Vim.
+mod block;
+mod paragraph;
+mod quote;
+mod word;
+
+pub use self::block::*;
+pub use paragraph::*;
+pub use quote::*;
+pub use word::*;

crates/vim/src/text_objects/paragraph.rs

@@ -0,0 +1,102 @@
+use std::ops::Range;
+
+use string_offset::CharOffset;
+use warpui::text::TextBuffer;
+
+use crate::{find_next_paragraph_end, find_previous_paragraph_start};
+
+/// Vim's "inner paragraph" text object, e.g. `dip`. This includes lines surrounding the cursor
+/// until blank lines are encountered in either direction, not including either blank line.
+/// See https://vimdoc.sourceforge.net/htmldoc/motion.html#ip
+/// or enter ":help ip" in Vim.
+///
+/// Returns None when the buffer is empty or the offset is out of bounds.
+pub fn vim_inner_paragraph<T, C>(buffer: &T, offset: C) -> Option<Range<CharOffset>>
+where
+    T: TextBuffer + ?Sized,
+    C: Into<CharOffset>,
+{
+    let offset = offset.into();
+    let mut chars = buffer.chars_at(offset).ok()?.peekable();
+    if chars.peek().is_some_and(|c| *c == '\n') {
+        let paragraph_end = offset - 1 + chars.take_while(|c| *c == '\n').count();
+        let paragraph_start = offset + 1
+            - buffer
+                .chars_rev_at(offset)
+                .ok()?
+                .take_while(|c| *c == '\n')
+                .count();
+        return Some(paragraph_start..paragraph_end);
+    }
+    let paragraph_start = find_previous_paragraph_start(buffer, offset)
+        .map(|i| i + 1)
+        .unwrap_or_default();
+    let paragraph_end = find_next_paragraph_end(buffer, offset)
+        .map(|i| i - 1)
+        .unwrap_or_else(|| offset + chars.count());
+
+    Some(paragraph_start..paragraph_end)
+}
+
+/// Vim's "a paragraph" text object, e.g. `dap`. This includes lines surrounding the cursor until
+/// blank lines are encountered in either direction, including one blank line. Usually the blank
+/// line to be included is the one following, unless the paragraph is at the end of the buffer in
+/// which case we include the one preceding.
+/// See https://vimdoc.sourceforge.net/htmldoc/motion.html#ap
+/// or enter ":help ap" in Vim.
+///
+/// Returns None when the buffer is empty or the offset is out of bounds.
+pub fn vim_a_paragraph<T, C>(buffer: &T, offset: C) -> Option<Range<CharOffset>>
+where
+    T: TextBuffer + ?Sized,
+    C: Into<CharOffset>,
+{
+    let offset = offset.into();
+    let mut chars = buffer.chars_at(offset).ok()?.peekable();
+    if chars.peek().is_some_and(|c| *c == '\n') {
+        let paragraph_end = find_next_paragraph_end(buffer, offset)
+            .map(|i| i - 1)
+            .unwrap_or_else(|| offset + chars.count());
+        let paragraph_start = offset + 1
+            - buffer
+                .chars_rev_at(offset)
+                .ok()?
+                .take_while(|c| *c == '\n')
+                .count();
+        return Some(paragraph_start..paragraph_end);
+    }
+    let end_offset = find_next_paragraph_end(buffer, offset);
+    // We either need to include all the consecutive blank lines above or below the paragraph
+    // content.
+    let paragraph_start = find_previous_paragraph_start(buffer, offset)
+        .map(|i| {
+            // If end_offset is Some, we'll include the consecutive blank lines below.
+            if end_offset.is_some() {
+                i + 1
+            } else {
+                // Calculate the number of blank lines above the start of the paragraph content.
+                i + 1
+                    - buffer
+                        .chars_rev_at(i)
+                        .map(|chars| chars.take_while(|c| *c == '\n').count())
+                        .unwrap_or_default()
+            }
+        })
+        .unwrap_or_default();
+    let paragraph_end = end_offset
+        .map(|i| {
+            // Calculate the number of blank lines below the end of the paragraph content.
+            i - 1
+                + buffer
+                    .chars_at(i)
+                    .map(|chars| chars.take_while(|c| *c == '\n').count())
+                    .unwrap_or_default()
+        })
+        .unwrap_or_else(|| offset + chars.count());
+
+    Some(paragraph_start..paragraph_end)
+}
+
+#[cfg(test)]
+#[path = "paragraph_tests.rs"]
+mod tests;

crates/vim/src/text_objects/paragraph_tests.rs

@@ -0,0 +1,208 @@
+use super::*;
+
+#[test]
+fn vim_inner_paragraph_empty_buffer() {
+    assert_eq!(vim_inner_paragraph("", 0), Some(0.into()..0.into()));
+    assert_eq!(vim_inner_paragraph("", 1), None);
+}
+
+#[test]
+fn vim_a_paragraph_empty_buffer() {
+    assert_eq!(vim_a_paragraph("", 0), Some(0.into()..0.into()));
+    assert_eq!(vim_a_paragraph("", 1), None);
+}
+
+#[test]
+fn vim_inner_paragraph_single_paragraph() {
+    let text = "foo bar\nnext line\n";
+
+    for (i, ch) in text.chars().enumerate() {
+        if ch != '\n' {
+            let range = vim_inner_paragraph(text, i).unwrap();
+            assert_eq!(range, 0.into()..text.len().into());
+        }
+    }
+}
+
+#[test]
+fn vim_a_paragraph_single_paragraph() {
+    let text = "foo bar\nnext line\n";
+
+    for (i, ch) in text.chars().enumerate() {
+        if ch != '\n' {
+            let range = vim_a_paragraph(text, i).unwrap();
+            assert_eq!(range, 0.into()..text.len().into());
+        }
+    }
+}
+
+#[test]
+fn vim_inner_paragraph_two_paragraphs() {
+    let text = "first line\nof first para\n\nsecond para line\n";
+    let blank_index = text.find("\n\n").unwrap();
+    let second_start = blank_index + 2;
+
+    for (i, ch) in text.chars().take(blank_index).enumerate() {
+        if ch != '\n' {
+            let range = vim_inner_paragraph(text, i).unwrap();
+            assert_eq!(range, 0.into()..blank_index.into());
+        }
+    }
+
+    for (i, ch) in text.chars().enumerate().skip(second_start) {
+        if ch != '\n' {
+            let range = vim_inner_paragraph(text, i).unwrap();
+            assert_eq!(range, second_start.into()..text.len().into());
+        }
+    }
+}
+
+#[test]
+fn vim_inner_paragraph_three_paragraphs() {
+    let text = "first\n\nsecond\n\nthird\n";
+    let (first_blank, second_blank) = {
+        let mut it = text.match_indices("\n\n");
+        (it.next().unwrap().0, it.next().unwrap().0)
+    };
+    let second_start = first_blank + 2;
+    let third_start = second_blank + 2;
+
+    for (i, ch) in text.chars().take(first_blank).enumerate() {
+        if ch != '\n' {
+            let range = vim_inner_paragraph(text, i).unwrap();
+            assert_eq!(range, 0.into()..first_blank.into());
+        }
+    }
+
+    for (i, ch) in text
+        .chars()
+        .enumerate()
+        .skip(second_start)
+        .take(second_blank - second_start)
+    {
+        if ch != '\n' {
+            let range = vim_inner_paragraph(text, i).unwrap();
+            assert_eq!(range, second_start.into()..second_blank.into());
+        }
+    }
+
+    for (i, ch) in text.chars().enumerate().skip(third_start) {
+        if ch != '\n' {
+            let range = vim_inner_paragraph(text, i).unwrap();
+            assert_eq!(range, third_start.into()..text.len().into());
+        }
+    }
+}
+
+#[test]
+fn vim_a_paragraph_two_paragraphs() {
+    let text = "first line\nof first para\n\nsecond para line\n";
+    let blank_index = text.find("\n\n").unwrap();
+
+    for (i, ch) in text.chars().take(blank_index).enumerate() {
+        if ch != '\n' {
+            let range = vim_a_paragraph(text, i).unwrap();
+            assert_eq!(range, 0.into()..(blank_index + 1).into());
+        }
+    }
+
+    let second_range_start = (blank_index + 1).into();
+    let second_range_end = text.len().into();
+    let second_start = blank_index + 2;
+
+    for (i, ch) in text.chars().enumerate().skip(second_start) {
+        if ch != '\n' {
+            let range = vim_a_paragraph(text, i).unwrap();
+            assert_eq!(range, second_range_start..second_range_end);
+        }
+    }
+}
+
+#[test]
+fn vim_a_paragraph_three_paragraphs() {
+    let text = "first\n\nsecond\n\nthird\n";
+    let (first_blank, second_blank) = {
+        let mut it = text.match_indices("\n\n");
+        (it.next().unwrap().0, it.next().unwrap().0)
+    };
+    let second_start = first_blank + 2;
+    let third_start = second_blank + 2;
+
+    for (i, ch) in text.chars().take(first_blank).enumerate() {
+        if ch != '\n' {
+            let range = vim_a_paragraph(text, i).unwrap();
+            assert_eq!(range, 0.into()..(first_blank + 1).into());
+        }
+    }
+
+    for (i, ch) in text
+        .chars()
+        .enumerate()
+        .skip(second_start)
+        .take(second_blank - second_start)
+    {
+        if ch != '\n' {
+            let range = vim_a_paragraph(text, i).unwrap();
+            assert_eq!(range, second_start.into()..(second_blank + 1).into());
+        }
+    }
+
+    let last_range = (second_blank + 1).into()..text.len().into();
+    for (i, ch) in text.chars().enumerate().skip(third_start) {
+        if ch != '\n' {
+            let range = vim_a_paragraph(text, i).unwrap();
+            assert_eq!(range, last_range);
+        }
+    }
+}
+
+#[test]
+fn vim_inner_paragraph_blank_lines() {
+    let text = "first\n\n\nsecond\n";
+
+    for offset in 5..=7 {
+        let range = vim_inner_paragraph(text, offset).unwrap();
+        assert_eq!(range, 6.into()..7.into());
+    }
+}
+
+#[test]
+fn vim_a_paragraph_blank_lines() {
+    let text = "first\n\n\nsecond\n";
+
+    for offset in 5..=7 {
+        let range = vim_a_paragraph(text, offset).unwrap();
+        assert_eq!(range, 6.into()..text.len().into());
+    }
+}
+
+#[test]
+fn vim_a_paragraph_many_trailing_blank_lines() {
+    let text = "first\n\n\nsecond\n\n\n\n\nthird";
+
+    for offset in 0..=4 {
+        let range = vim_a_paragraph(text, offset).unwrap();
+        assert_eq!(range, 0.into()..7.into());
+    }
+
+    for offset in 8..=13 {
+        let range = vim_a_paragraph(text, offset).unwrap();
+        assert_eq!(range, 8.into()..18.into());
+    }
+
+    for offset in 19..=23 {
+        let range = vim_a_paragraph(text, offset).unwrap();
+        assert_eq!(range, 15.into()..24.into());
+    }
+}
+
+#[test]
+fn vim_paragraph_lines_with_spaces_included() {
+    // Despite being invisible, a line containing spaces still counts as "content".
+    let text = "first\n\n    \nsecond";
+
+    let range = vim_a_paragraph(text, 3).unwrap();
+    assert_eq!(range, 0.into()..6.into());
+    let range = vim_a_paragraph(text, 14).unwrap();
+    assert_eq!(range, 6.into()..18.into());
+}

crates/vim/src/text_objects/quote.rs

@@ -0,0 +1,118 @@
+use std::ops::Range;
+
+use itertools::Itertools;
+use string_offset::CharOffset;
+use warpui::text::TextBuffer;
+
+use crate::vim::QuoteType;
+
+/// Vim's "inner quote" text object, e.g. `di"`. This includes characters enclosed by quotes.
+/// See https://vimdoc.sourceforge.net/htmldoc/motion.html#iquote
+/// or enter ":help iquote" in Vim.
+///
+/// Returns None when the line is empty, doesn't contain a pair of the quotes we're looking for, or
+/// the offset is out of bounds.
+pub fn vim_inner_quote<T, C>(
+    buffer: &T,
+    offset: C,
+    quote_type: QuoteType,
+) -> Option<Range<CharOffset>>
+where
+    T: TextBuffer + ?Sized,
+    C: Into<CharOffset>,
+{
+    vim_a_quote(buffer, offset, quote_type).map(|range| (range.start + 1)..(range.end - 1))
+}
+
+/// Vim's "a quote" text object, e.g. `da"`. This includes characters enclosed by quotes along with
+/// the quotes themselves.
+/// See https://vimdoc.sourceforge.net/htmldoc/motion.html#aquote
+/// or enter ":help aquote" in Vim.
+///
+/// Returns None when the line is empty, doesn't contain a pair of the quotes we're looking for, or
+/// the offset is out of bounds.
+pub fn vim_a_quote<T, C>(buffer: &T, offset: C, quote_type: QuoteType) -> Option<Range<CharOffset>>
+where
+    T: TextBuffer + ?Sized,
+    C: Into<CharOffset>,
+{
+    let offset = offset.into();
+    let mut forward_iter = buffer
+        .chars_at(offset)
+        .ok()?
+        .take_while(|c| *c != '\n') // cannot traverse newline boundaries
+        .enumerate()
+        .peekable();
+    let backward_iter = buffer
+        .chars_rev_at(offset)
+        .ok()?
+        .take_while(|c| *c != '\n')
+        .enumerate()
+        .peekable();
+
+    // This will be None if the line is empty
+    let (_, c) = forward_iter.next()?;
+
+    // First, check if the cursor is currently on top of a quote.
+    if !quote_type.is_char(c) {
+        // If not, see if there are quotes surrounding the cursor, one before one after.
+        let mut quote_behind_found_at = None;
+        for (i, c) in backward_iter {
+            if quote_type.is_char(c) {
+                quote_behind_found_at = Some(offset - i - 1);
+                break;
+            }
+        }
+        let mut quote_ahead_fount_at = None;
+        for (i, c) in &mut forward_iter {
+            if quote_type.is_char(c) {
+                quote_ahead_fount_at = Some(offset + i);
+                break;
+            }
+        }
+
+        match (quote_behind_found_at, quote_ahead_fount_at) {
+            // If there are quotes surrounding the cursor, take that range.
+            (Some(start), Some(end)) => Some(start..end + 1),
+            // If there is no quote before, but there _is_ one after, treat the one after as the
+            // opening quote and look for a closing quote after that.
+            (None, Some(start)) => {
+                for (i, c) in forward_iter {
+                    if quote_type.is_char(c) {
+                        let end = offset + i + 1;
+                        return Some(start..end);
+                    }
+                }
+                None
+            }
+            // Otherwise, no valid range. Vim doesn't attempt to look for a pair of quotes behind.
+            (_, None) => None,
+        }
+    } else {
+        // If the cursor is on a quote, we need to count all quotes on this line to figure out if
+        // this should be treated as an opening or closing quote.
+        let quotes_behind = backward_iter
+            .filter(|(_, c)| quote_type.is_char(*c))
+            .collect_vec();
+        // If there is an odd number of quotes before this one, then treat this one as closing.
+        if quotes_behind.len() % 2 == 1 {
+            let (i, _) = quotes_behind[0];
+            let start = offset - i - 1;
+            let end = offset + 1;
+            Some(start..end)
+        } else {
+            // If there is an even number of quotes before this one, treat this one as opening.
+            for (i, c) in forward_iter {
+                if quote_type.is_char(c) {
+                    let end = offset + i + 1;
+                    return Some(offset..end);
+                }
+            }
+            None
+        }
+    }
+}
+
+#[cfg(test)]
+#[path = "quote_tests.rs"]
+mod tests;

crates/vim/src/text_objects/quote_tests.rs

@@ -0,0 +1,114 @@
+use super::*;
+use crate::vim::QuoteType;
+
+#[test]
+fn test_a_quote() {
+    assert_eq!(vim_a_quote("", 0, QuoteType::Single), None);
+    assert_eq!(
+        vim_a_quote("'foo'", 1, QuoteType::Single).unwrap(),
+        0.into()..5.into()
+    );
+    assert_eq!(
+        vim_a_quote("'foo'", 0, QuoteType::Single).unwrap(),
+        0.into()..5.into()
+    );
+    assert_eq!(
+        vim_a_quote("'foo'", 4, QuoteType::Single).unwrap(),
+        0.into()..5.into()
+    );
+    assert_eq!(vim_a_quote("'foo'", 1, QuoteType::Double), None);
+    assert_eq!(vim_a_quote("'foo'  ", 5, QuoteType::Single), None);
+    assert_eq!(
+        vim_a_quote("foo  'foo' ", 0, QuoteType::Single).unwrap(),
+        5.into()..10.into()
+    );
+    assert_eq!(
+        vim_a_quote(r#"foo  "" "#, 0, QuoteType::Double).unwrap(),
+        5.into()..7.into()
+    );
+
+    //          0000000000111111111
+    //          0123456789012345678
+    let line = "  'foo'  'bar' 'baz";
+    for i in 0..=6 {
+        assert_eq!(
+            vim_a_quote(line, i, QuoteType::Single).unwrap(),
+            2.into()..7.into()
+        )
+    }
+    for i in 7..=8 {
+        assert_eq!(
+            vim_a_quote(line, i, QuoteType::Single).unwrap(),
+            6.into()..10.into()
+        )
+    }
+    for i in 9..=13 {
+        assert_eq!(
+            vim_a_quote(line, i, QuoteType::Single).unwrap(),
+            9.into()..14.into()
+        )
+    }
+    assert_eq!(
+        vim_a_quote(line, 14, QuoteType::Single).unwrap(),
+        13.into()..16.into()
+    );
+    for i in 15..=18 {
+        assert_eq!(vim_a_quote(line, i, QuoteType::Single), None)
+    }
+}
+
+#[test]
+fn test_inner_quote() {
+    assert_eq!(vim_inner_quote("", 0, QuoteType::Single), None);
+    assert_eq!(
+        vim_inner_quote("`foo`", 1, QuoteType::Backtick).unwrap(),
+        1.into()..4.into()
+    );
+    assert_eq!(
+        vim_inner_quote("`foo`", 0, QuoteType::Backtick).unwrap(),
+        1.into()..4.into()
+    );
+    assert_eq!(
+        vim_inner_quote("'foo'", 4, QuoteType::Single).unwrap(),
+        1.into()..4.into()
+    );
+    assert_eq!(vim_inner_quote("'foo'", 1, QuoteType::Double), None);
+    assert_eq!(vim_inner_quote("'foo'  ", 5, QuoteType::Single), None);
+    assert_eq!(
+        vim_inner_quote("foo  'foo' ", 0, QuoteType::Single).unwrap(),
+        6.into()..9.into()
+    );
+    assert_eq!(
+        vim_inner_quote(r#"foo  "" "#, 0, QuoteType::Double).unwrap(),
+        6.into()..6.into()
+    );
+
+    //          0000000000111111111
+    //          0123456789012345678
+    let line = "  'foo'  'bar' 'baz";
+    for i in 0..=6 {
+        assert_eq!(
+            vim_inner_quote(line, i, QuoteType::Single).unwrap(),
+            3.into()..6.into()
+        )
+    }
+    for i in 7..=8 {
+        assert_eq!(
+            vim_inner_quote(line, i, QuoteType::Single).unwrap(),
+            7.into()..9.into()
+        )
+    }
+    for i in 9..=13 {
+        assert_eq!(
+            vim_inner_quote(line, i, QuoteType::Single).unwrap(),
+            10.into()..13.into()
+        )
+    }
+    assert_eq!(
+        vim_inner_quote(line, 14, QuoteType::Single).unwrap(),
+        14.into()..15.into()
+    );
+    for i in 15..=18 {
+        assert_eq!(vim_inner_quote(line, i, QuoteType::Single), None)
+    }
+}

crates/vim/src/text_objects/word.rs

@@ -0,0 +1,152 @@
+use std::ops::Range;
+
+use string_offset::CharOffset;
+use warpui::text::TextBuffer;
+
+use crate::{vim::WordType, word_iterator::CharacterKind};
+
+/// Vim's "inner word" text object, e.g. `diw`. This includes the series of either word chars,
+/// symbols, or whitespace around the cursor.
+/// See https://vimdoc.sourceforge.net/htmldoc/motion.html#iw
+/// or enter ":help iw" in Vim.
+///
+/// Returns None when the buffer is empty or the offset is out of bounds.
+pub fn vim_inner_word<T, C>(buffer: &T, offset: C, word_type: WordType) -> Option<Range<CharOffset>>
+where
+    T: TextBuffer + ?Sized,
+    C: Into<CharOffset>,
+{
+    let offset = offset.into();
+    let mut forward_iter = buffer.chars_at(offset).ok()?.peekable();
+    // Empty buffer will be None here.
+    let cursor_context = CharacterKind::from(*forward_iter.peek()?);
+
+    let mut word_start = offset;
+    let backward_iter = buffer.chars_rev_at(offset).ok()?;
+    for c in backward_iter {
+        if !CharacterKind::from(c).equivalent_char_kind(&cursor_context, word_type) {
+            break;
+        }
+        word_start -= 1;
+    }
+
+    let mut word_end = offset;
+    for c in forward_iter {
+        if !CharacterKind::from(c).equivalent_char_kind(&cursor_context, word_type) {
+            break;
+        }
+        word_end += 1;
+    }
+
+    Some(word_start..word_end)
+}
+
+/// Vim's "a word" text object, e.g. `daw`. This includes the series of either word chars or
+/// symbols around the cursor as well as the section of whitespace after it (or if there is no
+/// whitespace after it, then before it).
+/// See https://vimdoc.sourceforge.net/htmldoc/motion.html#aw
+/// or enter ":help aw" in Vim.
+///
+/// Returns None when the buffer is empty or the offset is out of bounds.
+pub fn vim_a_word<T, C>(buffer: &T, offset: C, word_type: WordType) -> Option<Range<CharOffset>>
+where
+    T: TextBuffer + ?Sized,
+    C: Into<CharOffset>,
+{
+    let offset = offset.into();
+    let mut forward_iter = buffer.chars_at(offset).ok()?.peekable();
+    // Empty buffer will be None here.
+    let cursor_context = CharacterKind::from(*forward_iter.peek()?);
+
+    let mut word_start = offset;
+    let mut word_end = offset;
+    let mut backward_iter = buffer.chars_rev_at(offset).ok()?.peekable();
+
+    // Go back to the beginning of this context.
+    while let Some(&c) = backward_iter.peek() {
+        if !CharacterKind::from(c).equivalent_char_kind(&cursor_context, word_type) {
+            break;
+        }
+        word_start -= 1;
+        backward_iter.next();
+    }
+
+    // Proceed to the end of this context.
+    while let Some(&c) = forward_iter.peek() {
+        if !CharacterKind::from(c).equivalent_char_kind(&cursor_context, word_type) {
+            break;
+        }
+        word_end += 1;
+        forward_iter.next();
+    }
+
+    // If the cursor is in whitespace it needs to get the non-whitespace word ahead.
+    if cursor_context == CharacterKind::Whitespace {
+        // Check if there as non-whitespace after this.
+        let Some(&c) = forward_iter.peek() else {
+            // If this is the end of the buffer, we're done.
+            return Some(word_start..word_end);
+        };
+        let next_cursor_context = CharacterKind::from(c);
+
+        // Proceed to the end of this non-whitespace word.
+        for c in forward_iter {
+            if !CharacterKind::from(c).equivalent_char_kind(&next_cursor_context, word_type) {
+                break;
+            }
+            word_end += 1;
+        }
+        return Some(word_start..word_end);
+    }
+
+    // If we've made it this far, then the cursor did not start off in whitespace. This means we
+    // need to include some whitespace around this word. If there is whitespace ahead, include
+    // that. Otherwise, if there is whitespace behind, include that.
+
+    // If there is no content in this buffer ahead of this context.
+    let Some(&c) = forward_iter.peek() else {
+        // Check if there is any content behind.
+        let Some(&c) = backward_iter.peek() else {
+            return Some(word_start..word_end);
+        };
+        // Go backwards to include the whitespace.
+        if CharacterKind::from(c) == CharacterKind::Whitespace {
+            for c in backward_iter {
+                if CharacterKind::from(c) != CharacterKind::Whitespace {
+                    break;
+                }
+                word_start -= 1;
+            }
+        }
+        return Some(word_start..word_end);
+    };
+
+    // If we made it this far, there is content ahead of this context in the buffer.
+    if CharacterKind::from(c) == CharacterKind::Whitespace {
+        // If the content ahead as whitespace, include that.
+        for c in forward_iter {
+            if CharacterKind::from(c) != CharacterKind::Whitespace {
+                break;
+            }
+            word_end += 1;
+        }
+    } else {
+        // If the content ahead is not whitespace, try to include any whitespace behind.
+        let Some(&c) = backward_iter.peek() else {
+            return Some(word_start..word_end);
+        };
+        if CharacterKind::from(c) == CharacterKind::Whitespace {
+            for c in backward_iter {
+                if CharacterKind::from(c) != CharacterKind::Whitespace {
+                    break;
+                }
+                word_start -= 1;
+            }
+        }
+    }
+    Some(word_start..word_end)
+}
+
+#[cfg(test)]
+#[path = "word_tests.rs"]
+mod tests;

crates/vim/src/text_objects/word_tests.rs

@@ -0,0 +1,451 @@
+use super::*;
+
+#[test]
+fn test_vim_inner_word() {
+    assert_eq!(vim_inner_word("", 0, WordType::Default), None);
+    assert_eq!(
+        vim_inner_word("foo", 0, WordType::Default).unwrap(),
+        0.into()..3.into()
+    );
+    assert_eq!(
+        vim_inner_word("foo<<?>>", 4, WordType::Default).unwrap(),
+        3.into()..8.into()
+    );
+
+    //          000000000011111111112222222222333333333344444444445555555555666666666677
+    //          012345678901234567890123456789012345678901234567890123456789012345678901
+    let line = "impl<'a, T: TextBuffer + ?Sized + 'a>   Iterator for WordBoundariesVim {";
+    for i in 0..=3 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::Default).unwrap(),
+            0.into()..4.into()
+        );
+    }
+    for i in 4..=5 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::Default).unwrap(),
+            4.into()..6.into()
+        );
+    }
+    assert_eq!(
+        vim_inner_word(line, 6, WordType::Default).unwrap(),
+        6.into()..7.into()
+    );
+    assert_eq!(
+        vim_inner_word(line, 7, WordType::Default).unwrap(),
+        7.into()..8.into()
+    );
+    assert_eq!(
+        vim_inner_word(line, 8, WordType::Default).unwrap(),
+        8.into()..9.into()
+    );
+    assert_eq!(
+        vim_inner_word(line, 9, WordType::Default).unwrap(),
+        9.into()..10.into()
+    );
+    assert_eq!(
+        vim_inner_word(line, 10, WordType::Default).unwrap(),
+        10.into()..11.into()
+    );
+    for i in 12..=21 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::Default).unwrap(),
+            12.into()..22.into()
+        );
+    }
+    assert_eq!(
+        vim_inner_word(line, 22, WordType::Default).unwrap(),
+        22.into()..23.into()
+    );
+    assert_eq!(
+        vim_inner_word(line, 23, WordType::Default).unwrap(),
+        23.into()..24.into()
+    );
+    for i in 26..=30 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::Default).unwrap(),
+            26.into()..31.into()
+        );
+    }
+    for i in 37..=39 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::Default).unwrap(),
+            37.into()..40.into()
+        );
+    }
+    for i in 40..=47 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::Default).unwrap(),
+            40.into()..48.into()
+        );
+    }
+    assert_eq!(
+        vim_inner_word(line, 48, WordType::Default).unwrap(),
+        48.into()..49.into()
+    );
+    assert_eq!(
+        vim_inner_word(line, 71, WordType::Default).unwrap(),
+        71.into()..72.into()
+    );
+}
+
+#[test]
+fn test_vim_a_word() {
+    assert_eq!(vim_a_word("", 0, WordType::Default), None);
+    assert_eq!(
+        vim_a_word("foo", 0, WordType::Default).unwrap(),
+        0.into()..3.into()
+    );
+    assert_eq!(
+        vim_a_word("  foo", 0, WordType::Default).unwrap(),
+        0.into()..5.into()
+    );
+    assert_eq!(
+        vim_a_word("  foo", 1, WordType::Default).unwrap(),
+        0.into()..5.into()
+    );
+    assert_eq!(
+        vim_a_word("  foo", 3, WordType::Default).unwrap(),
+        0.into()..5.into()
+    );
+    assert_eq!(
+        vim_a_word("foo ", 1, WordType::Default).unwrap(),
+        0.into()..4.into()
+    );
+    assert_eq!(
+        vim_a_word("foo  ", 1, WordType::Default).unwrap(),
+        0.into()..5.into()
+    );
+    assert_eq!(
+        vim_a_word("foo  ", 3, WordType::Default).unwrap(),
+        3.into()..5.into()
+    );
+
+    //          00000000001111111111222222222233333333334444444444555555
+    //          01234567890123456789012345678901234567890123456789012345
+    let line = "impl<T>  Thing<T> { fn foo(&self,foo   :&Foo, a:i32) {{{";
+
+    for i in 0..=3 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::Default).unwrap(),
+            0.into()..4.into()
+        );
+    }
+    assert_eq!(
+        vim_a_word(line, 4, WordType::Default).unwrap(),
+        4.into()..5.into()
+    );
+    assert_eq!(
+        vim_a_word(line, 5, WordType::Default).unwrap(),
+        5.into()..6.into()
+    );
+    assert_eq!(
+        vim_a_word(line, 6, WordType::Default).unwrap(),
+        6.into()..9.into()
+    );
+    for i in 7..=13 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::Default).unwrap(),
+            7.into()..14.into()
+        );
+    }
+    assert_eq!(
+        vim_a_word(line, 16, WordType::Default).unwrap(),
+        16.into()..18.into()
+    );
+    assert_eq!(
+        vim_a_word(line, 17, WordType::Default).unwrap(),
+        17.into()..19.into()
+    );
+    assert_eq!(
+        vim_a_word(line, 18, WordType::Default).unwrap(),
+        18.into()..20.into()
+    );
+    assert_eq!(
+        vim_a_word(line, 19, WordType::Default).unwrap(),
+        19.into()..22.into()
+    );
+    for i in 20..=21 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::Default).unwrap(),
+            20.into()..23.into()
+        );
+    }
+    assert_eq!(
+        vim_a_word(line, 22, WordType::Default).unwrap(),
+        22.into()..26.into()
+    );
+    for i in 23..=25 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::Default).unwrap(),
+            22.into()..26.into()
+        );
+    }
+    for i in 26..=27 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::Default).unwrap(),
+            26.into()..28.into()
+        );
+    }
+    for i in 28..=31 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::Default).unwrap(),
+            28.into()..32.into()
+        );
+    }
+    assert_eq!(
+        vim_a_word(line, 32, WordType::Default).unwrap(),
+        32.into()..33.into()
+    );
+    for i in 33..=35 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::Default).unwrap(),
+            33.into()..39.into()
+        );
+    }
+    for i in 36..=40 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::Default).unwrap(),
+            36.into()..41.into()
+        );
+    }
+    for i in 41..=43 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::Default).unwrap(),
+            41.into()..44.into()
+        );
+    }
+    assert_eq!(
+        vim_a_word(line, 44, WordType::Default).unwrap(),
+        44.into()..46.into()
+    );
+    for i in 45..=46 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::Default).unwrap(),
+            45.into()..47.into()
+        );
+    }
+    assert_eq!(
+        vim_a_word(line, 47, WordType::Default).unwrap(),
+        47.into()..48.into()
+    );
+    for i in 48..=50 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::Default).unwrap(),
+            48.into()..51.into()
+        );
+    }
+    assert_eq!(
+        vim_a_word(line, 51, WordType::Default).unwrap(),
+        51.into()..53.into()
+    );
+    assert_eq!(
+        vim_a_word(line, 52, WordType::Default).unwrap(),
+        52.into()..56.into()
+    );
+    for i in 53..=55 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::Default).unwrap(),
+            52.into()..56.into()
+        );
+    }
+}
+
+#[test]
+fn test_vim_inner_bigword() {
+    assert_eq!(vim_inner_word("", 0, WordType::BigWord), None);
+    assert_eq!(
+        vim_inner_word("foo", 0, WordType::BigWord).unwrap(),
+        0.into()..3.into()
+    );
+    assert_eq!(
+        vim_inner_word("foo<<?>>", 4, WordType::BigWord).unwrap(),
+        0.into()..8.into()
+    );
+
+    //          000000000011111111112222222222333333333344444444445555555555666666666677
+    //          012345678901234567890123456789012345678901234567890123456789012345678901
+    let line = "impl<'a, T: TextBuffer + ?Sized + 'a>   Iterator for WordBoundariesVim {";
+    for i in 0..=7 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::BigWord).unwrap(),
+            0.into()..8.into()
+        );
+    }
+    assert_eq!(
+        vim_inner_word(line, 8, WordType::BigWord).unwrap(),
+        8.into()..9.into()
+    );
+    for i in 9..=10 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::BigWord).unwrap(),
+            9.into()..11.into()
+        );
+    }
+    assert_eq!(
+        vim_inner_word(line, 11, WordType::BigWord).unwrap(),
+        11.into()..12.into()
+    );
+    for i in 12..=21 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::BigWord).unwrap(),
+            12.into()..22.into()
+        );
+    }
+    assert_eq!(
+        vim_inner_word(line, 22, WordType::BigWord).unwrap(),
+        22.into()..23.into()
+    );
+    assert_eq!(
+        vim_inner_word(line, 23, WordType::BigWord).unwrap(),
+        23.into()..24.into()
+    );
+    assert_eq!(
+        vim_inner_word(line, 24, WordType::BigWord).unwrap(),
+        24.into()..25.into()
+    );
+    for i in 25..=30 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::BigWord).unwrap(),
+            25.into()..31.into()
+        );
+    }
+    for i in 34..=36 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::BigWord).unwrap(),
+            34.into()..37.into()
+        );
+    }
+    for i in 37..=39 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::BigWord).unwrap(),
+            37.into()..40.into()
+        );
+    }
+    for i in 40..=47 {
+        assert_eq!(
+            vim_inner_word(line, i, WordType::BigWord).unwrap(),
+            40.into()..48.into()
+        );
+    }
+    assert_eq!(
+        vim_inner_word(line, 48, WordType::BigWord).unwrap(),
+        48.into()..49.into()
+    );
+    assert_eq!(
+        vim_inner_word(line, 71, WordType::BigWord).unwrap(),
+        71.into()..72.into()
+    );
+}
+
+#[test]
+fn test_vim_a_bigword() {
+    assert_eq!(vim_a_word("", 0, WordType::BigWord), None);
+    assert_eq!(
+        vim_a_word("foo.bar", 0, WordType::BigWord).unwrap(),
+        0.into()..7.into()
+    );
+    assert_eq!(
+        vim_a_word("  foo.bar", 0, WordType::BigWord).unwrap(),
+        0.into()..9.into()
+    );
+    assert_eq!(
+        vim_a_word("  foo.bar", 1, WordType::BigWord).unwrap(),
+        0.into()..9.into()
+    );
+    assert_eq!(
+        vim_a_word("  foo.bar", 3, WordType::BigWord).unwrap(),
+        0.into()..9.into()
+    );
+    assert_eq!(
+        vim_a_word("foo.bar ", 1, WordType::BigWord).unwrap(),
+        0.into()..8.into()
+    );
+    assert_eq!(
+        vim_a_word("foo.bar  ", 1, WordType::BigWord).unwrap(),
+        0.into()..9.into()
+    );
+    assert_eq!(
+        vim_a_word("foo.bar  ", 7, WordType::BigWord).unwrap(),
+        7.into()..9.into()
+    );
+
+    //          00000000001111111111222222222233333333334444444444555555
+    //          01234567890123456789012345678901234567890123456789012345
+    let line = "impl<T>  Thing<T> { fn foo(&self,foo   :&Foo, a:i32) {{{";
+
+    for i in 0..=6 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::BigWord).unwrap(),
+            0.into()..9.into()
+        );
+    }
+    for i in 7..=8 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::BigWord).unwrap(),
+            7.into()..17.into()
+        );
+    }
+    for i in 9..=16 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::BigWord).unwrap(),
+            9.into()..18.into()
+        );
+    }
+    assert_eq!(
+        vim_a_word(line, 17, WordType::BigWord).unwrap(),
+        17.into()..19.into()
+    );
+    assert_eq!(
+        vim_a_word(line, 18, WordType::BigWord).unwrap(),
+        18.into()..20.into()
+    );
+    assert_eq!(
+        vim_a_word(line, 19, WordType::BigWord).unwrap(),
+        19.into()..22.into()
+    );
+    for i in 20..=21 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::BigWord).unwrap(),
+            20.into()..23.into()
+        );
+    }
+    assert_eq!(
+        vim_a_word(line, 22, WordType::BigWord).unwrap(),
+        22.into()..36.into()
+    );
+    for i in 23..=35 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::BigWord).unwrap(),
+            23.into()..39.into()
+        );
+    }
+    for i in 36..=38 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::BigWord).unwrap(),
+            36.into()..45.into()
+        );
+    }
+    for i in 39..=44 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::BigWord).unwrap(),
+            39.into()..46.into()
+        );
+    }
+    assert_eq!(
+        vim_a_word(line, 45, WordType::BigWord).unwrap(),
+        45.into()..52.into()
+    );
+    for i in 46..=51 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::BigWord).unwrap(),
+            46.into()..53.into()
+        );
+    }
+    for i in 52..=55 {
+        assert_eq!(
+            vim_a_word(line, i, WordType::BigWord).unwrap(),
+            52.into()..56.into()
+        );
+    }
+}

crates/vim/src/word_iterator.rs

@@ -0,0 +1,250 @@
+use std::iter::Peekable;
+
+use anyhow::Result;
+use itertools::{peek_nth, Either, PeekNth};
+use string_offset::CharOffset;
+use warpui::text::{words::is_default_word_boundary, TextBuffer};
+
+use crate::vim::{Direction, WordBound, WordType};
+
+/// The "kind" of character that a char is. "Symbols" here refer to non-whitespace characters that
+/// are traditionally word-breaking characters, e.g. punctuation and brackets. Vim treats contiguous
+/// symbols as their own "words" and hence they need to be tracked as a distinct context from
+/// word-characters and whitespace.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub(super) enum CharacterKind {
+    WordChars,
+    Symbols,
+    Whitespace,
+}
+
+impl CharacterKind {
+    /// This is an alternative to `==` which will treat Self::WordChars and Self::Symbols as equal
+    /// to one another for WordType::BigWord. This is useful for motions or text objects
+    /// involving bigwords.
+    pub(super) fn equivalent_char_kind(&self, other: &Self, word_type: WordType) -> bool {
+        match word_type {
+            WordType::Default => self == other,
+            WordType::BigWord => {
+                self == other
+                    || (*self == Self::WordChars && *other == Self::Symbols
+                        || *self == Self::Symbols && *other == Self::WordChars)
+            }
+        }
+    }
+}
+
+impl From<char> for CharacterKind {
+    fn from(c: char) -> Self {
+        if c.is_whitespace() {
+            CharacterKind::Whitespace
+        } else if is_default_word_boundary(c) {
+            CharacterKind::Symbols
+        } else {
+            CharacterKind::WordChars
+        }
+    }
+}
+
+/// This function abstracts over the different specific types of word iterators. This is meant to
+/// be used by Views rather than any of these iterator structs.
+pub fn vim_word_iterator_from_offset<'a, T, C>(
+    offset: C,
+    buffer: &'a T,
+    direction: Direction,
+    bound: WordBound,
+    word_type: WordType,
+) -> Result<Box<dyn Iterator<Item = CharOffset> + 'a>>
+where
+    T: TextBuffer + ?Sized + 'a,
+    C: Into<CharOffset>,
+{
+    let offset = offset.into();
+    match (direction, bound) {
+        (Direction::Forward, WordBound::Start) | (Direction::Backward, WordBound::End) => Ok(
+            Box::new(WordHeadsVim::new(offset, buffer, direction, word_type)?),
+        ),
+        (Direction::Forward, WordBound::End) | (Direction::Backward, WordBound::Start) => Ok(
+            Box::new(WordTailsVim::new(offset, buffer, direction, word_type)?),
+        ),
+    }
+}
+
+/// This struct represents the logic for pressing either w, W, ge, or gE in Vim.
+pub struct WordHeadsVim<'a, T: TextBuffer + ?Sized + 'a> {
+    offset: CharOffset,
+    chars: Peekable<Either<T::Chars<'a>, T::CharsReverse<'a>>>,
+    cursor_context: CharacterKind,
+    direction: Direction,
+    word_type: WordType,
+    done: bool,
+}
+
+impl<'a, T: TextBuffer + ?Sized + 'a> WordHeadsVim<'a, T> {
+    pub fn new(
+        offset: CharOffset,
+        buffer: &'a T,
+        direction: Direction,
+        word_type: WordType,
+    ) -> Result<Self> {
+        let (offset, mut chars) = match direction {
+            // TextBuffer::chars_rev_at does not include the character _at_ the originating offset.
+            // However, Vim's word motion semantics require that we see the character at the
+            // originating offset, so we need to +1 the offset before creating the reverse char
+            // iterator.
+            Direction::Backward => {
+                let offset = offset + 1;
+                (
+                    offset,
+                    Either::Right(buffer.chars_rev_at(offset)?).peekable(),
+                )
+            }
+            Direction::Forward => (offset, Either::Left(buffer.chars_at(offset)?).peekable()),
+        };
+        Ok(Self {
+            offset,
+            cursor_context: chars
+                .peek()
+                .map_or(CharacterKind::WordChars, |c| (*c).into()),
+            chars,
+            direction,
+            word_type,
+            done: false,
+        })
+    }
+
+    fn step(&mut self) {
+        self.chars.next();
+        match self.direction {
+            Direction::Backward => self.offset -= 1,
+            Direction::Forward => self.offset += 1,
+        }
+    }
+}
+
+impl<'a, T: TextBuffer + ?Sized + 'a> Iterator for WordHeadsVim<'a, T> {
+    type Item = CharOffset;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.done {
+            return None;
+        }
+
+        loop {
+            self.step();
+            let Some(&c) = self.chars.peek() else {
+                break;
+            };
+            let prev_cursor_context = self.cursor_context;
+            self.cursor_context = CharacterKind::from(c);
+
+            if !self
+                .cursor_context
+                .equivalent_char_kind(&prev_cursor_context, self.word_type)
+                && self.cursor_context != CharacterKind::Whitespace
+            {
+                return Some(match self.direction {
+                    Direction::Backward => self.offset - 1,
+                    Direction::Forward => self.offset,
+                });
+            }
+        }
+
+        self.done = true;
+        Some(self.offset)
+    }
+}
+
+/// This struct represents the logic for pressing either b, B, e, or E in Vim.
+pub struct WordTailsVim<'a, T: TextBuffer + ?Sized + 'a> {
+    offset: CharOffset,
+    chars: PeekNth<Either<T::Chars<'a>, T::CharsReverse<'a>>>,
+    direction: Direction,
+    word_type: WordType,
+    done: bool,
+}
+
+impl<'a, T: TextBuffer + ?Sized + 'a> WordTailsVim<'a, T> {
+    pub fn new(
+        offset: CharOffset,
+        buffer: &'a T,
+        direction: Direction,
+        word_type: WordType,
+    ) -> Result<Self> {
+        let (offset, chars) = match direction {
+            // TextBuffer::chars_rev_at does not include the character _at_ the originating offset.
+            // However, Vim's word motion semantics require that we see the character at the
+            // originating offset, so we need to +1 the offset before creating the reverse char
+            // iterator.
+            Direction::Backward => {
+                let offset = offset + 1;
+                (
+                    offset,
+                    peek_nth(Either::Right(buffer.chars_rev_at(offset)?)),
+                )
+            }
+            Direction::Forward => (offset, peek_nth(Either::Left(buffer.chars_at(offset)?))),
+        };
+        Ok(Self {
+            offset,
+            chars,
+            direction,
+            word_type,
+            done: false,
+        })
+    }
+
+    fn step(&mut self) {
+        self.chars.next();
+        match self.direction {
+            Direction::Backward => self.offset -= 1,
+            Direction::Forward => self.offset += 1,
+        }
+    }
+}
+
+impl<'a, T: TextBuffer + ?Sized + 'a> Iterator for WordTailsVim<'a, T> {
+    type Item = CharOffset;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.done {
+            return None;
+        }
+
+        loop {
+            if self.chars.peek_nth(1).is_none() {
+                break;
+            }
+            self.step();
+
+            let Some(&c) = self.chars.peek() else {
+                break;
+            };
+            let Some(&c_next) = self.chars.peek_nth(1) else {
+                break;
+            };
+
+            let cursor_context = CharacterKind::from(c);
+            let cursor_context_next = CharacterKind::from(c_next);
+
+            if !cursor_context.equivalent_char_kind(&cursor_context_next, self.word_type)
+                && cursor_context != CharacterKind::Whitespace
+            {
+                return Some(match self.direction {
+                    Direction::Backward => self.offset - 1,
+                    Direction::Forward => self.offset,
+                });
+            }
+        }
+
+        self.done = true;
+        Some(match self.direction {
+            Direction::Backward => self.offset - 1,
+            Direction::Forward => self.offset,
+        })
+    }
+}
+
+#[cfg(test)]
+#[path = "word_iterator_tests.rs"]
+mod tests;

crates/vim/src/word_iterator_tests.rs

@@ -0,0 +1,573 @@
+use super::*;
+
+//                  0000000000111111111122222222223333333333444444444455555555556666666666
+//                  0123456789012345678901234567890123456789012345678901234567890123456789
+const LINE: &str = "impl<'a, T: TextBuffer + ?Sized + 'a>   Iterator for WordBoundariesVim";
+
+/// The behavior for pressing "w".
+#[test]
+fn test_word_forward_heads() {
+    let mut iter1 = vim_word_iterator_from_offset(
+        0,
+        LINE,
+        Direction::Forward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+
+    assert_eq!(iter1.next(), Some(4.into()));
+    assert_eq!(iter1.next(), Some(6.into()));
+    assert_eq!(iter1.next(), Some(7.into()));
+    assert_eq!(iter1.next(), Some(9.into()));
+    assert_eq!(iter1.next(), Some(10.into()));
+    assert_eq!(iter1.next(), Some(12.into()));
+    assert_eq!(iter1.next(), Some(23.into()));
+    assert_eq!(iter1.next(), Some(25.into()));
+    assert_eq!(iter1.next(), Some(26.into()));
+    assert_eq!(iter1.next(), Some(32.into()));
+    assert_eq!(iter1.next(), Some(34.into()));
+    assert_eq!(iter1.next(), Some(35.into()));
+    assert_eq!(iter1.next(), Some(36.into()));
+    assert_eq!(iter1.next(), Some(40.into()));
+    assert_eq!(iter1.next(), Some(49.into()));
+    assert_eq!(iter1.next(), Some(53.into()));
+    assert_eq!(iter1.next(), Some(70.into()));
+    assert_eq!(iter1.next(), None);
+
+    let mut iter2 = vim_word_iterator_from_offset(
+        15,
+        LINE,
+        Direction::Forward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter2.next(), Some(23.into()));
+
+    let mut iter3 = vim_word_iterator_from_offset(
+        43,
+        LINE,
+        Direction::Forward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter3.next(), Some(49.into()));
+
+    let mut iter4 = vim_word_iterator_from_offset(
+        38,
+        LINE,
+        Direction::Forward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter4.next(), Some(40.into()));
+
+    let mut iter5 = vim_word_iterator_from_offset(
+        69,
+        LINE,
+        Direction::Forward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter5.next(), Some(70.into()));
+    assert_eq!(iter5.next(), None);
+}
+
+/// The behavior for pressing "W".
+#[test]
+fn test_word_forward_heads_including_symbols() {
+    let mut iter1 = vim_word_iterator_from_offset(
+        0,
+        LINE,
+        Direction::Forward,
+        WordBound::Start,
+        WordType::BigWord,
+    )
+    .unwrap();
+
+    assert_eq!(iter1.next(), Some(9.into()));
+    assert_eq!(iter1.next(), Some(12.into()));
+    assert_eq!(iter1.next(), Some(23.into()));
+    assert_eq!(iter1.next(), Some(25.into()));
+    assert_eq!(iter1.next(), Some(32.into()));
+    assert_eq!(iter1.next(), Some(34.into()));
+    assert_eq!(iter1.next(), Some(40.into()));
+    assert_eq!(iter1.next(), Some(49.into()));
+    assert_eq!(iter1.next(), Some(53.into()));
+    assert_eq!(iter1.next(), Some(70.into()));
+    assert_eq!(iter1.next(), None);
+
+    let mut iter2 = vim_word_iterator_from_offset(
+        15,
+        LINE,
+        Direction::Forward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter2.next(), Some(23.into()));
+
+    let mut iter3 = vim_word_iterator_from_offset(
+        43,
+        LINE,
+        Direction::Forward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter3.next(), Some(49.into()));
+
+    let mut iter4 = vim_word_iterator_from_offset(
+        38,
+        LINE,
+        Direction::Forward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter4.next(), Some(40.into()));
+
+    let mut iter5 = vim_word_iterator_from_offset(
+        69,
+        LINE,
+        Direction::Forward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter5.next(), Some(70.into()));
+    assert_eq!(iter5.next(), None);
+}
+
+/// The behavior for pressing "ge"
+#[test]
+fn test_word_backward_heads() {
+    let mut iter1 = vim_word_iterator_from_offset(
+        69,
+        LINE,
+        Direction::Backward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+
+    assert_eq!(iter1.next(), Some(51.into()));
+    assert_eq!(iter1.next(), Some(47.into()));
+    assert_eq!(iter1.next(), Some(36.into()));
+    assert_eq!(iter1.next(), Some(35.into()));
+    assert_eq!(iter1.next(), Some(34.into()));
+    assert_eq!(iter1.next(), Some(32.into()));
+    assert_eq!(iter1.next(), Some(30.into()));
+    assert_eq!(iter1.next(), Some(25.into()));
+    assert_eq!(iter1.next(), Some(23.into()));
+    assert_eq!(iter1.next(), Some(21.into()));
+    assert_eq!(iter1.next(), Some(10.into()));
+    assert_eq!(iter1.next(), Some(9.into()));
+    assert_eq!(iter1.next(), Some(7.into()));
+    assert_eq!(iter1.next(), Some(6.into()));
+    assert_eq!(iter1.next(), Some(5.into()));
+    assert_eq!(iter1.next(), Some(3.into()));
+    assert_eq!(iter1.next(), Some(0.into()));
+    assert_eq!(iter1.next(), None);
+
+    let mut iter2 = vim_word_iterator_from_offset(
+        15,
+        LINE,
+        Direction::Backward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter2.next(), Some(10.into()));
+
+    let mut iter3 = vim_word_iterator_from_offset(
+        43,
+        LINE,
+        Direction::Backward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter3.next(), Some(36.into()));
+
+    let mut iter4 = vim_word_iterator_from_offset(
+        38,
+        LINE,
+        Direction::Backward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter4.next(), Some(36.into()));
+
+    let mut iter5 = vim_word_iterator_from_offset(
+        0,
+        LINE,
+        Direction::Backward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter5.next(), Some(0.into()));
+    assert_eq!(iter5.next(), None);
+}
+
+/// The behavior for pressing "gE"
+#[test]
+fn test_word_backward_heads_including_symbols() {
+    let mut iter1 = vim_word_iterator_from_offset(
+        69,
+        LINE,
+        Direction::Backward,
+        WordBound::End,
+        WordType::BigWord,
+    )
+    .unwrap();
+
+    assert_eq!(iter1.next(), Some(51.into()));
+    assert_eq!(iter1.next(), Some(47.into()));
+    assert_eq!(iter1.next(), Some(36.into()));
+    assert_eq!(iter1.next(), Some(32.into()));
+    assert_eq!(iter1.next(), Some(30.into()));
+    assert_eq!(iter1.next(), Some(23.into()));
+    assert_eq!(iter1.next(), Some(21.into()));
+    assert_eq!(iter1.next(), Some(10.into()));
+    assert_eq!(iter1.next(), Some(7.into()));
+    assert_eq!(iter1.next(), Some(0.into()));
+    assert_eq!(iter1.next(), None);
+
+    let mut iter2 = vim_word_iterator_from_offset(
+        15,
+        LINE,
+        Direction::Backward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter2.next(), Some(10.into()));
+
+    let mut iter3 = vim_word_iterator_from_offset(
+        43,
+        LINE,
+        Direction::Backward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter3.next(), Some(36.into()));
+
+    let mut iter4 = vim_word_iterator_from_offset(
+        38,
+        LINE,
+        Direction::Backward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter4.next(), Some(36.into()));
+
+    let mut iter5 = vim_word_iterator_from_offset(
+        0,
+        LINE,
+        Direction::Backward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter5.next(), Some(0.into()));
+    assert_eq!(iter5.next(), None);
+}
+
+/// The behavior for pressing "e"
+#[test]
+fn test_word_forward_tails() {
+    let mut iter1 = vim_word_iterator_from_offset(
+        0,
+        LINE,
+        Direction::Forward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+
+    assert_eq!(iter1.next(), Some(3.into()));
+    assert_eq!(iter1.next(), Some(5.into()));
+    assert_eq!(iter1.next(), Some(6.into()));
+    assert_eq!(iter1.next(), Some(7.into()));
+    assert_eq!(iter1.next(), Some(9.into()));
+    assert_eq!(iter1.next(), Some(10.into()));
+    assert_eq!(iter1.next(), Some(21.into()));
+    assert_eq!(iter1.next(), Some(23.into()));
+    assert_eq!(iter1.next(), Some(25.into()));
+    assert_eq!(iter1.next(), Some(30.into()));
+    assert_eq!(iter1.next(), Some(32.into()));
+    assert_eq!(iter1.next(), Some(34.into()));
+    assert_eq!(iter1.next(), Some(35.into()));
+    assert_eq!(iter1.next(), Some(36.into()));
+    assert_eq!(iter1.next(), Some(47.into()));
+    assert_eq!(iter1.next(), Some(51.into()));
+    assert_eq!(iter1.next(), Some(69.into()));
+    assert_eq!(iter1.next(), None);
+
+    let mut iter2 = vim_word_iterator_from_offset(
+        15,
+        LINE,
+        Direction::Forward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter2.next(), Some(21.into()));
+
+    let mut iter3 = vim_word_iterator_from_offset(
+        43,
+        LINE,
+        Direction::Forward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter3.next(), Some(47.into()));
+
+    let mut iter4 = vim_word_iterator_from_offset(
+        38,
+        LINE,
+        Direction::Forward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter4.next(), Some(47.into()));
+
+    let mut iter5 = vim_word_iterator_from_offset(
+        69,
+        LINE,
+        Direction::Forward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter5.next(), Some(69.into()));
+    assert_eq!(iter5.next(), None);
+}
+
+/// The behavior for pressing "E"
+#[test]
+fn test_word_forward_tails_including_symbols() {
+    let mut iter1 = vim_word_iterator_from_offset(
+        0,
+        LINE,
+        Direction::Forward,
+        WordBound::End,
+        WordType::BigWord,
+    )
+    .unwrap();
+
+    assert_eq!(iter1.next(), Some(7.into()));
+    assert_eq!(iter1.next(), Some(10.into()));
+    assert_eq!(iter1.next(), Some(21.into()));
+    assert_eq!(iter1.next(), Some(23.into()));
+    assert_eq!(iter1.next(), Some(30.into()));
+    assert_eq!(iter1.next(), Some(32.into()));
+    assert_eq!(iter1.next(), Some(36.into()));
+    assert_eq!(iter1.next(), Some(47.into()));
+    assert_eq!(iter1.next(), Some(51.into()));
+    assert_eq!(iter1.next(), Some(69.into()));
+    assert_eq!(iter1.next(), None);
+
+    let mut iter2 = vim_word_iterator_from_offset(
+        15,
+        LINE,
+        Direction::Forward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter2.next(), Some(21.into()));
+
+    let mut iter3 = vim_word_iterator_from_offset(
+        43,
+        LINE,
+        Direction::Forward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter3.next(), Some(47.into()));
+
+    let mut iter4 = vim_word_iterator_from_offset(
+        38,
+        LINE,
+        Direction::Forward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter4.next(), Some(47.into()));
+
+    let mut iter5 = vim_word_iterator_from_offset(
+        69,
+        LINE,
+        Direction::Forward,
+        WordBound::End,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter5.next(), Some(69.into()));
+    assert_eq!(iter5.next(), None);
+}
+
+/// The behavior for pressing "b"
+#[test]
+fn test_word_backward_tails() {
+    let mut iter1 = vim_word_iterator_from_offset(
+        69,
+        LINE,
+        Direction::Backward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+
+    assert_eq!(iter1.next(), Some(53.into()));
+    assert_eq!(iter1.next(), Some(49.into()));
+    assert_eq!(iter1.next(), Some(40.into()));
+    assert_eq!(iter1.next(), Some(36.into()));
+    assert_eq!(iter1.next(), Some(35.into()));
+    assert_eq!(iter1.next(), Some(34.into()));
+    assert_eq!(iter1.next(), Some(32.into()));
+    assert_eq!(iter1.next(), Some(26.into()));
+    assert_eq!(iter1.next(), Some(25.into()));
+    assert_eq!(iter1.next(), Some(23.into()));
+    assert_eq!(iter1.next(), Some(12.into()));
+    assert_eq!(iter1.next(), Some(10.into()));
+    assert_eq!(iter1.next(), Some(9.into()));
+    assert_eq!(iter1.next(), Some(7.into()));
+    assert_eq!(iter1.next(), Some(6.into()));
+    assert_eq!(iter1.next(), Some(4.into()));
+    assert_eq!(iter1.next(), Some(0.into()));
+    assert_eq!(iter1.next(), None);
+
+    let mut iter2 = vim_word_iterator_from_offset(
+        15,
+        LINE,
+        Direction::Backward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter2.next(), Some(12.into()));
+
+    let mut iter3 = vim_word_iterator_from_offset(
+        43,
+        LINE,
+        Direction::Backward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter3.next(), Some(40.into()));
+
+    let mut iter4 = vim_word_iterator_from_offset(
+        38,
+        LINE,
+        Direction::Backward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter4.next(), Some(36.into()));
+
+    let mut iter5 = vim_word_iterator_from_offset(
+        0,
+        LINE,
+        Direction::Backward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter5.next(), Some(0.into()));
+    assert_eq!(iter5.next(), None);
+}
+
+/// The behavior for pressing "B"
+#[test]
+fn test_word_backward_tails_including_symbols() {
+    let mut iter1 = vim_word_iterator_from_offset(
+        69,
+        LINE,
+        Direction::Backward,
+        WordBound::Start,
+        WordType::BigWord,
+    )
+    .unwrap();
+
+    assert_eq!(iter1.next(), Some(53.into()));
+    assert_eq!(iter1.next(), Some(49.into()));
+    assert_eq!(iter1.next(), Some(40.into()));
+    assert_eq!(iter1.next(), Some(34.into()));
+    assert_eq!(iter1.next(), Some(32.into()));
+    assert_eq!(iter1.next(), Some(25.into()));
+    assert_eq!(iter1.next(), Some(23.into()));
+    assert_eq!(iter1.next(), Some(12.into()));
+    assert_eq!(iter1.next(), Some(9.into()));
+    assert_eq!(iter1.next(), Some(0.into()));
+    assert_eq!(iter1.next(), None);
+
+    let mut iter2 = vim_word_iterator_from_offset(
+        15,
+        LINE,
+        Direction::Backward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter2.next(), Some(12.into()));
+
+    let mut iter3 = vim_word_iterator_from_offset(
+        43,
+        LINE,
+        Direction::Backward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter3.next(), Some(40.into()));
+
+    let mut iter4 = vim_word_iterator_from_offset(
+        38,
+        LINE,
+        Direction::Backward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter4.next(), Some(36.into()));
+
+    let mut iter5 = vim_word_iterator_from_offset(
+        0,
+        LINE,
+        Direction::Backward,
+        WordBound::Start,
+        WordType::Default,
+    )
+    .unwrap();
+    assert_eq!(iter5.next(), Some(0.into()));
+    assert_eq!(iter5.next(), None);
+}
+
+#[test]
+fn test_out_of_bounds_is_error() {
+    assert!(vim_word_iterator_from_offset(
+        70,
+        LINE,
+        Direction::Backward,
+        WordBound::Start,
+        WordType::BigWord
+    )
+    .is_err());
+}