feat: parse matchspec conditions and translate to resolvo

[wolfv]

This PR implements parsing for conditions in MatchSpecs, following the syntax described in conda/ceps#111

Conditions can be used to enable or disable dependencies under certain conditions (such as other packages or virtual packages in the same environment).

They are written in the following way:

• numpy; if python >=3.12
• pywin32; if __win
• foobar; if __unix and python >=3.12
• complex; if (a or b) and (b and c)

Conditions are only allowed in run dependencies, and not in constraints. Nesting conditions is also not allowed (e.g. foobar; if __win; if __python >=3.12 is invalid).

[Copilot]

Pull Request Overview

This PR implements parsing and translation of conditional dependencies in MatchSpecs according to the conda CEP specification. It enables dependencies to be conditionally included based on conditions like Python version or virtual packages using syntax such as numpy; if python >=3.12 or foobar; if __unix.

• Adds parsing support for condition syntax in MatchSpecs with logical operators (and, or) and parentheses
• Implements translation from parsed conditions to resolvo's conditional requirement system
• Updates dependency processing to handle conditional requirements throughout the solver pipeline

Reviewed Changes

Copilot reviewed 14 out of 15 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
crates/rattler_conda_types/src/match_spec/condition.rs	New module implementing condition parsing with logical operators and MatchSpec evaluation
crates/rattler_conda_types/src/match_spec/parse.rs	Updated parser to extract and parse condition clauses from MatchSpec strings
crates/rattler_conda_types/src/match_spec/mod.rs	Added condition field to MatchSpec struct and Display implementation
crates/rattler_solve/src/resolvo/mod.rs	Modified dependency provider to translate conditions and handle conditional requirements
crates/rattler_solve/tests/backends.rs	Added comprehensive test for conditional dependency resolution
crates/rattler_pty/src/unix/pty_session.rs	Removed continue statement in error handling loop
Cargo.toml	Updated resolvo dependency to development branch with condition support

[baszalmstra]

I had a hard time understanding what a Statement is. Especially the prefix field. Maybe add some comments to clarify.

[baszalmstra]

This seems to only be used in the tests

[wolfv]

Yeah this is indeed only used in the tests. I thought I moved it there.

[baszalmstra]

One slight issue I have with this approach is that some information is lost when converting from a string. E.g. converting back to a string loses the order and parenthesis.

Im wondering if we can structure this differently or add a wrapping struct that holds the original statement or something along those lines. Ideally we build a concrete syntax tree.

The reason this is important is that when we report the conditions in an unsat error you want the information to closely resemble the users input.

[wolfv]

@baszalmstra actually we have a few corner cases with our proposed syntax:

            "deep; if foobar >=1.23 *or* and(b >32.12,<=43 *and or(c and d))",

Or in other words, we cannot use and or or in build strings anymore.

Maybe it would be better to go for a "C-like" syntax, using && and || as they are not found and hopefully forbidden in build strings? Looks slightly uglier though!

[baszalmstra]

0.10.1 also seems to be available. Maybe we can bump to that in the lock-file.