wordcraft/docs/typing-parity.md

Typing parity with Word

Last reviewed: 2026-10-10 · Last updated: 2026-10-10 · Change: trivial (status line, revision history and links to the other parity docs added; behaviour unchanged) · Target: Microsoft Word (Microsoft 365) for Mac 16.113.4

What Word does when you type, observed black-box (same keystrokes typed into Word and WordCraft, results read back paragraph by paragraph) and pinned by tests in crates/engine/src/tests_typing.rs. When typing behaviour changes, change it here and in the tests together. Line breaking and pagination are in layout-parity.md; the overall picture is in target-app-parity.md.

Lists

Keys	Word's result	Test
* item Enter Enter text	the second Enter ends the list; text is a Normal paragraph (no list indent left behind)	enter_twice_after_a_list_item_ends_the_list, the_paragraph_after_a_list_is_normal_text
… Enter ×3, ×4	each further Enter adds a blank Normal paragraph (never swallowed)	more_enters_after_a_list_make_blank_paragraphs
Enter on an empty nested item	moves it up one level; only a top-level empty item leaves the list	enter_on_an_empty_nested_item_moves_it_up_a_level_first
* Enter (nothing typed)	list cancelled, Normal paragraph	enter_right_after_starting_a_list_cancels_it
Tab / Shift+Tab at the start of an item	demote / promote	shift_tab_and_tab_change_list_levels
Backspace at the start of an item	1st: number removed, indent kept; 2nd: Normal paragraph — not joined to the one above	backspace_at_the_start_of_an_item_removes_the_number_then_the_indent
Enter mid-item / at item start	splits the item / inserts an empty item above	enter_in_the_middle_or_at_the_start_of_an_item
Shift+Enter in an item	line break inside the same item	shift_enter_stays_inside_the_list_item
* - 1. 1) a. a) A. i. I. + text	bullet, dash bullet, 1. 1) a. a) A. i. I. lists	list_autoformat_triggers
1. after other text	a new list restarting at 1 (never continues an earlier list)	typing_1_dot_starts_numbering_again
⌘Z right after an AutoFormat	undoes only the AutoFormat (* comes back as text)	undo_right_after_autoformat_undoes_only_the_autoformat

Track Changes

Keys	Word's result	Test
Enter (tracking on)	the new paragraph mark is a tracked insertion; Reject All joins the paragraphs again, Accept All keeps them	tracked_enter_and_backspace_track_the_paragraph_mark, tests::reject_all_removes_a_tracked_paragraph_break
Backspace at a paragraph start / Delete at a paragraph end (tracking on)	the paragraph mark is marked deleted (still shown); the caret moves before it (Backspace) or past it (Delete). Accept joins the paragraphs, Reject keeps them. A mark you inserted yourself is just removed	tracked_enter_and_backspace_track_the_paragraph_mark, tests::tracked_backspace_and_delete_mark_a_paragraph_break_deleted

AutoCorrect and AutoFormat as you type

Applied when a word is finished by a space, punctuation or Enter (enter_finishes_a_word_for_autocorrect):

• First letter of a sentence (paragraph or list item start, after . ! ?) is capitalised; not after abbreviations (e.g., Dr., …) or initials (J.), and not for mixed-case words (iPhone) or single-letter labels (a.). teh→the, i→I, (c)→©, (tm)→™, wait...→wait…, smart quotes (autocorrect_as_you_type).
• 1/2 1/4 3/4 → ½ ¼ ¾; 1st 22nd 13th get superscript suffixes (ordinals_become_superscript).
• word -- word → en dash, word - word → en dash, word--word → em dash (dashes).
• Web addresses become links; following text isn't linked (web_addresses_become_links).
• Enter after --- === *** ___ ~~~ ### → a bottom border on the paragraph above (single, double, dotted, thick, wave, triple) (border_line_autoformat).

Layout

• No line break right after a slash (and/or, URLs) unless the word can't fit a line (layout::tests::no_line_break_right_after_a_slash).

Known gaps

• Word's body font Aptos isn't installed outside Office; our substitute (Carlito, else Helvetica Neue) is wider, so lines wrap earlier than in Word. Needs a metric-matched open substitute.
• :) inside a word (ok:)) isn't replaced (Word replaces it).
• Not yet compared: +---+---+ Enter (table AutoFormat), > arrow bullets, undo after a border line, Correct TWo INitial CApitals.

How to compare

• WordCraft: the headless ui_shot example (no window, no focus) with UI_SHOT_FULL=1 prints the whole document.inspect; drive it with ui.text / ui.key lines so keys take the real input path.
• Word: the machine is shared. Prefer AppleScript that doesn't take focus (open, read paragraphs, export PDF). Keystroke runs steal focus and race the person at the keyboard: keep them short, read the document back to verify, and ask first. Screenshots of Word's window only, under plan/word/screenshots/.

Revision history

Date	Change	Summary
2026-10-10	trivial	Status line, revision history and cross-links added (progress-docs standard)
2026-10-10	minor	Track Changes rows: tracked Enter, Backspace and Delete on paragraph marks (#244)
2026-10-10	major	First version: lists, AutoCorrect and AutoFormat as you type, observed against Word (#204)