Call a provider, validate JSON output, retry on failure

Sends prompt to provider, parses the response as JSON, and validates it against schema (a short schema name resolved via load_schema). If validation fails, the error message is appended to the prompt and the call is retried up to max_retries times.

Usage

validate_or_retry(provider, prompt, schema, max_retries = 3L, image = NULL)

Arguments

provider

An ellmer chat object (from vlm_provider) or a MockVLMProvider instance. Must expose a $chat(prompt, ...) method returning text (or a character vector of length 1).

prompt

Character scalar with the initial prompt.

schema

Short schema name ("horizon", "site").

max_retries

Integer; total attempts will be at most 1 + max_retries.

image

Optional ellmer image content object (e.g. from ellmer::content_image_file) to pass alongside the prompt for multimodal calls.

Value

A list with elements data (parsed R object), raw (character scalar), attempts (integer).

Details

On success, returns a list with the parsed JSON, the raw text, and the number of attempts taken. On terminal failure, throws.

This is the single place where the VLM-call -> validate -> retry contract is implemented; every user-facing extractor delegates here.