keyseq

Deterministic planner for human-like typing. Turns a string into a sequence of typing events — insert, delete, delay, idle — for a renderer to play back.

demo

Requirements

• OCaml ≥ 4.14 (uses String.get_utf_8_uchar).

Install

opam install keyseq

Use

let state = Random.State.make [| 1 |] in
match Keyseq.plan Keyseq.default_config state "Hello, world." with
| Ok events -> Keyseq_terminal.run events
| Error (Keyseq.Invalid_utf8 offset) ->
 Printf.eprintf "invalid UTF-8 at byte %d\n" offset

See examples/demo.ml for a complete, runnable example.

Behavior

• Sleep is an ordinary inter-character delay. Idle is a longer pause, following a sentence-ending . ! ?, during which a renderer may animate the cursor.
• Mid-clause punctuation (, ; : —) gets a Sleep pause only, no Idle.
• Typos are only generated for ASCII letters and Cyrillic-block letters; nothing else is ever mistyped, regardless of typo_rate.
• All randomness is explicit: callers pass a Random.State.t, and the library never calls Random.self_init. Same config, same unconsumed state, same input text — same output, every time.

Failure modes

• Keyseq.plan returns Error (Invalid_utf8 offset) if the input isn't valid UTF-8. offset is a byte offset.
• Keyseq.plan raises Invalid_argument if config violates its own preconditions (e.g. max_delay < min_delay) — this is a programmer error, not an input-validation failure.

License

ISC. See LICENSE.