Class: Ace::PromptPrep::Atoms::FrontmatterExtractor

Inherits:
Object
  • Object
show all
Defined in:
lib/ace/prompt_prep/atoms/frontmatter_extractor.rb

Overview

Extract YAML frontmatter from markdown content

Constant Summary collapse

FRONTMATTER_DELIMITER = 
/^---\s*$/

Class Method Summary collapse

Class Method Details

.extract(content) ⇒ Hash

Extract frontmatter and body from content

Parameters:

  • content (String) —

    The content to parse

Returns:

  • (Hash) —

    Hash with :frontmatter, :body, :has_frontmatter keys



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# File 'lib/ace/prompt_prep/atoms/frontmatter_extractor.rb', line 16

def self.extract(content)
  return empty_result(content) if content.nil? || content.empty?

  lines = content.lines
  return empty_result(content) unless lines.first&.match?(FRONTMATTER_DELIMITER)

  # Find closing delimiter
  closing_index = lines[1..].find_index { |line| line.match?(FRONTMATTER_DELIMITER) }
  return empty_result(content) unless closing_index

  # Extract frontmatter YAML (between delimiters)
  frontmatter_lines = lines[1..closing_index]
  frontmatter_yaml = frontmatter_lines.join

  # Parse YAML
  begin
    frontmatter = YAML.safe_load(frontmatter_yaml) || {}
  rescue Psych::SyntaxError, Psych::DisallowedClass => e
    # Invalid YAML - return as if no frontmatter
    return empty_result(content, error: "Invalid YAML in frontmatter: #{e.message}")
  end

  # Extract body (everything after closing delimiter)
  body_start = closing_index + 2 # +1 for array index offset, +1 for closing delimiter
  body = lines[body_start..].join

  {
    frontmatter: frontmatter,
    raw_frontmatter: frontmatter_yaml,
    body: body,
    has_frontmatter: true,
    error: nil
  }
end