Support enum types in Tools

[snapsl]

It is common to restrict the input for a function calls using enum type definition. link
It would be great to support this.

[DenisovAV]

Hi @snapsl, thanks for the suggestion!

Actually, enum types already work since parameters is just a JSON schema - you can add 'enum': [...] directly:

Tool(
  name: 'set_light',
  description: 'Set light color',
  parameters: {
    'type': 'object',
    'properties': {
      'color_temp': {
        'type': 'string',
        'enum': ['daylight', 'cool', 'warm'],
        'description': 'Color temperature',
      }
    }
  }
)

But you're right - a typed API would be more convenient and less error-prone. I'll add helper methods and proper documentation in one of the upcoming versions.

[snapsl]

Hi @DenisovAV,
If I understand this correctly, enums are not parsed to the model context when using functiongemma (should have mentioned that ealier).

flutter_gemma/lib/core/chat.dart

Line 408 in 9af00fa

String _createFunctionGemmaToolsPrompt() {

It probably works with the other models but I haven't tested it.

[DenisovAV]

You're right @snapsl, my bad! I'll fix it today/tomorrow.

[DenisovAV]

Taking longer than expected. The model hallucinating enum values after TFLite conversion — still investigating.