[feature] KEP-11385: Extend the SDK compiler to support Literal input parameters for both pipeline and component input

[mprahl]

Feature Area

/area sdk

Part of KEP-11385.

Acceptance Criteria

• InputSpec class definition contains a literals field of type Optional[List[str] | List[int] | List[float]] = None
• Compiler throws an error for Literal parameters that contain elements of multiple types (ie. Literal[1, 2, "a"]). While this behavior is supported by the typing.Literal class, we want to limit KFP to Literals of a single type.
• Compiler validates hard-coded input values against their Literal parameters. Compiler throws an error if input is invalid
• Validate these changes by adding the valid and invalid cases outlined in the KEP to the SDK compiler unit test cases.  Only include behavior outlined under the SDK Compiler column.

Hint: changes should be made primarily to  kfp/dsl/structures.py and kfp/dsl/types/type_utils.py

[krishi-agrawal]

hi, can i work on this?

[khushiiagrawal]

Hi @krishi-agrawal,

I’ve taken up the frontend issue #12603. From the discussion and @mprahl’s suggestion, it seems the /sdk implementation would need to be completed first.
If you’re interested in working on /sdk part, I’d be happy to align my work on the frontend accordingly.
Thanks!

[krishi-agrawal]

Yes, sure @khushiiagrawal !

[shreeharshshinde]

Hii all , I went ahead and implemented the SDK compiler portion of this issue based on the KEP acceptance criteria.
This PR focuses on the base support for Literal inputs (InputSpec, compiler validation, and tests).

I hope no one minds — Happy to coordinate or adjust if there’s any overlap with ongoing work.

[alyssacgoins]

@krishi-agrawal thanks for taking this issue! I'll take a look at your PR

[shreeharshshinde]

@krishi-agrawal thanks for taking this issue! I'll take a look at your PR

Hi @alyssacgoins, thanks for the update!

Just to clarify for context — I’ve already implemented the SDK compiler portion for this issue in PR #12606, covering the InputSpec literals field, compiler validation, and unit tests per the KEP acceptance criteria.

Happy to coordinate or adjust if there’s overlap with other work. Looking forward to your feedback!