Parallel each loops now supported

[slundberg]

You can now run each loops in parallel using the parallel=True parameter. This is can be useful if you are sending off lots of API calls in a loops and want them to run in parallel rather than serially. This is supported as of 0.0.62

Here is a simple example:

import guidance

guidance.llm = guidance.llms.OpenAI("text-curie-001")

program = guidance("""Hello, {{name}}! Here are 5 names and their favorite food:
{{#each names parallel=True hidden=True~}}
{{this}}: {{gen 'foods' list_append=True}}
{{/each}}""", llm=llm)

executed_program = program(name="Guidance", names=["Bob", "Sue", "Sam"])   

Note that you have to also set hidden=True when doing parallel loops because previous iterations of the loop cannot serve as context for future iterations if they are all run in parallel.