Add a utility to build "natural language functions"

[rlouf]

import json
import outlines.text as text
import outlines.models as models


@text.prompt
def prime_numbers(n: int):
    """Return a list that contains all prime numbers between 1 and {{n}}.

    The output must be parsable as a Python list.
    """

def parse(result):
    return json.loads(result)

get_prime_numbers = text.function(
   models.text_completion.openai("gpt-3.5-turbo"),
   prime_numbers,
   parse
)

get_prime_numbers(10)
# [2, 3, 5, 7]

For more complex outputs one can pass a Pydantic model to text.function, which will be used to parse the output:

from pydantic import BaseModel
import outlines.text as text

class Joke(BaseModel):
    joke: str
    explanation: str


@text.prompt
def joke_ppt(n: int):
    """Tell a joke and explain why the joke is funny.

    RESPONSE FORMAT:
    {
       "joke": "The joke"
       "explanation": "The explanation of why the joke is funny"
    }
    """

tell_a_joke = text.function(
   models.text_completion.openai("gpt-3.5-turbo"),
   joke_ppt,
   Joke
)

get_prime_numbers(10)
# [2, 3, 5, 7]