touchtype: A Progressive Touch Typing Trainer for Emacs

Each key has a confidence score between 0.0 and 1.0, calculated from both speed and accuracy:

target_ms        = 60000 / (target_wpm * 5)
avg_ms           = total_ms / hits
speed_confidence = min(1.0, target_ms / avg_ms)
accuracy         = hits / (hits + misses)
confidence       = accuracy * speed_confidence

Both dimensions must be high for full confidence. A key you type quickly but inaccurately won't unlock the next one, and neither will a key you type accurately but slowly. The unlock threshold is touchtype-unlock-threshold (default: 0.80).

A new key unlocks only when every currently unlocked key meets the threshold. This prevents rushing: you can't advance by nailing the new key while your old keys decay.

touchtype generates practice words using an English bigram frequency table, a 26x26 matrix of character transition weights. Generation works as a weighted random walk:

1. Pick a starting character, weighted by total outgoing bigram frequency.
2. Sample the next character from that character's bigram row, filtered to the currently allowed alphabet.
3. Terminate with probability that increases exponentially with word length (naturally producing 4-7 character words).
4. Inject the focused character (the most recently unlocked key) at a random position with 40% probability.

This produces words that feel like English, they follow natural letter patterns, even though they aren't real words. The focused character injection ensures you get enough practice on new keys without making every word feel artificial.

After each line, touchtype picks a "focus character" to emphasize:

• 70% of the time: the most recently unlocked key (deliberate practice on the new key).
• 30% of the time: a random key below the confidence threshold (remediation for weak keys).

This rotation ensures that newly unlocked keys get concentrated practice while weak older keys aren't forgotten.

The unlock order depends on your keyboard layout, spiraling outward from the home row by English letter frequency:

Each drill isolates a specific motor pattern. Bigram drills target two-finger transitions (th, he, in). Tetragram drills build four-character muscle memory for common word fragments (tion, ight, that).

Narrative mode downloads and caches books from Project Gutenberg, then serves random 400-character passages that land on word boundaries. The book list includes Pride and Prejudice, Alice's Adventures in Wonderland, Sherlock Holmes, Frankenstein, Moby Dick, and 15 others. You can add any valid Gutenberg ID to touchtype-narrative-book-list.

Code mode draws from a curated set of snippets: Python (8), Rust (7), Go (5), JavaScript/TypeScript (6), Emacs Lisp (4), Shell (4), SQL (4), and C (5). It includes the full printable ASCII range (chars 32-126), so you practice brackets, operators, and indentation, not just alphanumerics.

Enable touchtype-pace-caret to show a ghost cursor that moves at your target WPM. It's a visual indicator of whether you're ahead of or behind your target pace, without the pressure of a countdown timer.

Sessions can be word-count based or timed:

• Word-count: Default 30 words. Presets: short (15), medium (30), long (60), marathon (120). Set with M-x touchtype-set-session-length or a C-u N prefix argument.
• Timed: Default 60 seconds via M-x touchtype-timed. The timer starts on your first keypress, not when the buffer opens. Idle gaps longer than touchtype-idle-threshold (default: 10 seconds) are excluded from WPM calculations.

• Net WPM: (total_chars / 5 - uncorrected_errors) / minutes
• Gross WPM: (total_chars / 5) / minutes
• Net/Gross CPM: Characters per minute (wpm * 5)
• Accuracy: Percentage, ignoring corrected mistakes
• Raw Accuracy: True first-attempt accuracy, including corrections in the denominator

• Time: Elapsed excluding idle periods (mm:ss)
• Characters: Total keypresses including errors
• Corrections: Backspace count
• Uncorrected Errors: Mistakes left unfixed
• Consistency: Coefficient of variation of per-line WPM, subtracted from 100%
• WPM Sparkline: A Unicode bar chart (▁▂▃▄▅▆▇█) showing per-line WPM with min-max range
• Streak: Current daily practice streak
• Total Time: Cumulative across all sessions

The summary includes collapsible sections for your weakest letters, bigrams, trigrams, and tetragrams. Press RET on any section header to expand it. Weakest letters show the top 10 by confidence (expandable to all 26). N-gram sections show the top 5, expandable to 50. This tells you exactly what to focus on in your next session.

If you set a new personal best for that mode's net WPM, a banner announces it.

M-x touchtype-export writes your data to JSON or CSV. The JSON export includes sessions, per-letter stats with confidence scores, streak, and total practice time. The CSV export is a simple table of sessions (date, WPM, accuracy, mode, words).