Refinement Loops

repeat lets a tree express bounded retry and revision.

from jdsl import check, predict, repeat, root, sel, seq

skill = (
    root("Refine", system="One tight paragraph.")
    .model("deepseek-chat")
    .do(seq(
        predict("topic -> draft", instructions="Write one paragraph."),
        repeat(
            seq(
                predict(
                    "draft -> critique, ok",
                    instructions="Set ok to 'yes' if the draft is clear enough.",
                ),
                sel(
                    check("ok", "yes"),
                    predict("draft, critique -> draft", instructions="Revise the draft."),
                ),
            ),
            until=check("ok", "yes"),
            max=3,
        ),
    ))
)

Run the example:

uv run jdsl run examples/refine.py -i topic="why sourdough needs a starter"

Loop Semantics

repeat(child, until=guard, max=3) is do-while:

1. run child
2. check until
3. stop if it succeeds
4. repeat until max

If the child fails, the repeat fails immediately. If max is reached and until never passed, the repeat fails.

Skip Work with a Selector

The inner selector avoids revising a good draft:

sel(
    check("ok", "yes"),
    predict("draft, critique -> draft"),
)

When ok is yes, the selector succeeds at the guard and skips the revision branch.