Implement :from filter

[christian-schilling]

Change: from-filter

[Copilot]

Pull Request Overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 5 comments.

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[Copilot]

The filter_concat rule incorrectly uses "from" as its keyword instead of "concat". This will cause parsing conflicts since both filter_from and filter_concat would match the same input syntax :from(...). The keyword should be "concat" to match the intended :concat(...) syntax.

[christian-schilling]

already fixed

[Copilot]

The grammar for filter_from is more permissive than the implementation. The grammar allows optional arguments and multiple comma-separated pairs with (rev ~ filter_spec)? ~ (CMD_SEP+ ~ (rev ~ filter_spec))*, but the parsing code (lines 184-193 in parse.rs) requires exactly 2 elements. The grammar should enforce exactly one rev and one filter_spec by using rev ~ filter_spec without the optional ? and without the repetition *.

Suggested change

	~ (rev ~ filter_spec)?
	~ (CMD_SEP+ ~ (rev ~ filter_spec))*
	~ rev ~ filter_spec

[christian-schilling]

We want to combine all those similar rules into one eventually so I'd like to keep it the same as the others.

[Copilot]

The grammar for filter_concat is more permissive than the implementation. The grammar allows optional arguments and multiple comma-separated pairs with (rev ~ filter_spec)? ~ (CMD_SEP+ ~ (rev ~ filter_spec))*, but the parsing code (lines 198-204 in parse.rs) requires exactly 2 elements. The grammar should enforce exactly one rev and one filter_spec by using rev ~ filter_spec without the optional ? and without the repetition *.

Suggested change

	~ (rev ~ filter_spec)?
	~ (CMD_SEP+ ~ (rev ~ filter_spec))*
	~ rev ~ filter_spec

[christian-schilling]

Want to keep it like that for now to make it easier to see the similarity with other rules.

[Copilot]

The documentation is ambiguous about whether the specified commit itself is filtered. Based on the test case (concat.t), the specified commit remains unchanged and only commits AFTER it are filtered. The phrase "from that commit onwards" suggests the commit itself is filtered, but the actual behavior keeps it unchanged. Consider rephrasing to: "Produce a history that keeps the original history up to and including the specified commit <sha> unchanged, but applies the given :filter to all commits after that commit."

Suggested change

	Produce a history that keeps the original history leading up to the specified commit `<sha>` unchanged,
	but applies the given `:filter` to all commits from that commit onwards.
	Produce a history that keeps the original history up to and including the specified commit `<sha>` unchanged,
	but applies the given `:filter` to all commits after that commit.

[christian-schilling]

fixed