LeXtract.Prompting (lextract v0.1.2)

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Prompt generation for LLM extraction.

Creates structured prompts with few-shot examples to guide the LLM in extracting entities from text in the desired format.

Examples

iex> template = %{
...>   description: "Extract medications from clinical text",
...>   examples: [
...>     %{
...>       text: "Patient takes aspirin",
...>       extractions: [
...>         %{extraction_class: "medication", extraction_text: "aspirin"}
...>       ]
...>     }
...>   ]
...> }
iex> handler = LeXtract.FormatHandler.new(:json)
iex> generator = LeXtract.Prompting.new(template, handler)
iex> is_struct(generator, LeXtract.Prompting)
true

Summary

Types

t()
template()

Functions

format_example(generator, example)

Formats a single example as text (Q&A format).

new(template, format_handler, opts \\ [])

Creates a new prompt generator.

read_template(path, format)

Reads a prompt template from a JSON or YAML file.

render(generator, question, opts \\ [])

Renders a complete prompt for the LLM.

Types

t()

@type t() :: %LeXtract.Prompting{
  answer_prefix: String.t(),
  examples_heading: String.t(),
  format_handler: LeXtract.FormatHandler.t(),
  question_prefix: String.t(),
  template: template()
}

template()

@type template() :: %{
  description: String.t(),
  examples: [LeXtract.Document.example()]
}

Functions

format_example(generator, example)

@spec format_example(t(), LeXtract.Document.example()) :: String.t()

Formats a single example as text (Q&A format).

Converts an example into: Q: <example text> A: <formatted extractions in JSON/YAML>

Examples

iex> template = %{description: "Extract", examples: []}
iex> handler = LeXtract.FormatHandler.new(:json)
iex> generator = LeXtract.Prompting.new(template, handler)
iex> example = %{text: "John Doe", extractions: [%{entity: "John Doe"}]}
iex> formatted = LeXtract.Prompting.format_example(generator, example)
iex> String.contains?(formatted, "Q: John Doe")
true

new(template, format_handler, opts \\ [])

@spec new(template(), LeXtract.FormatHandler.t(), keyword()) :: t()

Creates a new prompt generator.

Parameters

  • template - Prompt template with description and examples
  • format_handler - Format handler for JSON/YAML output
  • opts - Options (see below)

Options

  • :examples_heading - Heading text for examples section (default: "Examples")
  • :question_prefix - Prefix for question lines (default: "Q: ")
  • :answer_prefix - Prefix for answer lines (default: "A: ")

Examples

iex> template = %{description: "Extract entities", examples: []}
iex> handler = LeXtract.FormatHandler.new(:json)
iex> generator = LeXtract.Prompting.new(template, handler)
iex> generator.examples_heading
"Examples"

iex> template = %{description: "Extract entities", examples: []}
iex> handler = LeXtract.FormatHandler.new(:yaml)
iex> generator = LeXtract.Prompting.new(template, handler, examples_heading: "Few-shot Examples")
iex> generator.examples_heading
"Few-shot Examples"

read_template(path, format)

@spec read_template(Path.t(), :json | :yaml) ::
  {:ok, template()} | {:error, Exception.t()}

Reads a prompt template from a JSON or YAML file.

Parameters

  • path - File path to template
  • format - :json or :yaml

Returns

{:ok, template} or {:error, exception}

Examples

iex> File.write!("/tmp/test_template.json", ~s({"description": "Test", "examples": []}))
iex> {:ok, template} = LeXtract.Prompting.read_template("/tmp/test_template.json", :json)
iex> template.description
"Test"
iex> File.rm("/tmp/test_template.json")
:ok

render(generator, question, opts \\ [])

@spec render(t(), String.t(), keyword()) :: String.t()

Renders a complete prompt for the LLM.

Combines:

  • Template description
  • Optional additional context
  • Few-shot examples (formatted)
  • The question text
  • Answer prefix to guide LLM response

Parameters

  • generator - The prompt generator
  • question - Text to extract from
  • opts - Options (see below)

Options

  • :additional_context - Extra context to include before examples

Returns

String prompt ready to send to LLM.

Examples

iex> template = %{description: "Extract people", examples: []}
iex> handler = LeXtract.FormatHandler.new(:json)
iex> generator = LeXtract.Prompting.new(template, handler)
iex> prompt = LeXtract.Prompting.render(generator, "John Doe works here")
iex> String.contains?(prompt, "Extract people")
true
iex> String.contains?(prompt, "Q: John Doe works here")
true