Structured error raised or returned by PdfElixide operations.

Non-bang functions return {:error, %PdfElixide.Error{}}; bang functions raise the same struct (it is an exception). Match on :reason to handle specific failures:

case PdfElixide.Document.open(path) do
  {:ok, doc} -> doc
  {:error, %PdfElixide.Error{reason: :encrypted}} -> prompt_for_password()
  {:error, %PdfElixide.Error{reason: :invalid_pdf}} -> reject()
end

Reasons

• :encrypted — the PDF is encrypted and needs a password first.
• :wrong_password — the supplied password was rejected.
• :invalid_pdf — malformed or unparseable PDF data.
• :unsupported — an unsupported PDF version, feature, or filter.
• :not_found — a referenced object was not found.
• :out_of_range — the page index is outside the document.
• :io — an underlying IO error.
• :lock_poisoned — the internal resource lock was poisoned.
• :other — any error not covered above; message is preserved verbatim.

:message is a human-readable description. :details is reserved for future structured payloads and is currently always nil.