Implement JSON schema field constraints

[rlouf]

We can specify constraints for the different fields in the JSON schema specification. Only maxLength for strings is currently implemented. Remaining:

Strings

• [x] minLength
• [x] pattern

and the default formats that can be specified via the format keyword:

• [ ] date-time
• [ ] time
• [ ] date
• [ ] duration
• [ ] email
• [ ] idn-email
• [ ] hostname
• [ ] idn-hostname
• [ ] ipv4
• [ ] ipv6
• [ ] uuid
• [ ] uri
• [ ] uri-reference
• [ ] iri
• [ ] iri-reference
• [ ] uri-template
• [ ] regex

Numeric types

• [ ] multipleOf
• [ ] minimum
• [ ] exclusiveMinimum
• [ ] maximum
• [ ] exclusiveMaximum

Arrays

• [ ] ~minItems~
• [ ] ~maxItems~
• [ ] ~uniqueItems~ (may only be applicable dynamically)
• [ ] Set length

Tuples

See https://json-schema.org/understanding-json-schema/reference/array#tupleValidation

Required fields

We should handle optional fields as well, i.e. those not specified in the required field of the schema.

[brandonwillard]

Here are some examples of integer range constraints expressed as regular expressions: https://stackoverflow.com/a/34680927/3006474, https://3widgets.com/

[CarloNicolini]

What is the status of this? Are length of tuples/lists also implemented?

[fire]

To be honest I switched to ggml’s ebnf for grammar constraints.

[brandonwillard]

To be honest I switched to ggml’s ebnf for grammar constraints.

How does an EBNF-specified grammar provide these constraints?

[Rassibassi]

While playing around trying to validate meta schemas, I ran into $recursiveRef or $dynamicRef, any thoughts on implementation of recursive schemas? I'd like to give it a try

$recursiveRef found in: https://json-schema.org/draft/2019-09/schema https://json-schema.org/draft/2019-09/meta/core

$dynamicRef found in: https://json-schema.org/draft/2020-12/schema https://json-schema.org/draft/2020-12/meta/core

[brandonwillard]

While playing around trying to validate meta schemas, I ran into $recursiveRef or $dynamicRef, any thoughts on implementation of recursive schemas? I'd like to give it a try

Regarding recursion, there's an existing issue for that (albeit framed via the Pydantic interface): https://github.com/outlines-dev/outlines/issues/330. Feel free to continue the discussion there.

[rlouf]

Development is now happening in outlines-core