Re: [PATCH v4 07/10] parseopt: autocorrect mistyped subcommands

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 16, 2026, 19:41 UTC
Message-ID: <xmqqse9zo93p.fsf@gitster.g>
In-Reply-To: <SY0P300MB0801E3F75349DFDF98C221F6CE40A@SY0P300MB0801.AUSP300.PROD.OUTLOOK.COM>

Jiamu Sun <39@barroit.sh> writes:

Show 13 quoted lines

> Try to autocorrect the mistyped mandatory subcommand before showing an
> error and exiting. Subcommands parsed with PARSE_OPT_SUBCOMMAND_OPTIONAL
> are skipped.
>
> Use standard Damerau-Levenshtein distance (weights 1, 1, 1, 1) to
> establish a predictable, mathematically sound baseline.
>
> Scale the allowed edit distance based on input length to prevent
> false positives on short commands, following common practice for
> fuzziness thresholds (e.g., Elasticsearch's AUTO fuzziness):
>   - Length 0-2: 0 edits allowed
>   - Length 3-5: 1 edit allowed
>   - Length 6+:  2 edits allowed

Is there a reason why this needs to differ from the settings for the typo detection/fixes for main commands? Would the same reasoning apply to both, and if not why not?

I would have expected that we would just emulate what we already do to the main commands, and later with experience with the subcommand typo detection/fixes, would tweak the parameters either only to the subcommand part or to the both with justifications.

Show 5 quoted lines

> +	/*
> +	 * Builtin subcommands are small enough that printing them all via
> +	 * usage_with_options() is sufficient. Therefore, AUTOCORRECT_HINT
> +	 * acts like AUTOCORRECT_NEVER.
> +	 */

Sorry, but I am a bit confused with this reference to "Builtin subcommands". Are there subcommands that are not built-in?