Function to_words_json_lines 

pub fn to_words_json_lines(words: &[Word]) -> String

The block model and both serialisations of it, re-exported from pdf-engine: what PdfDocument::extract_blocks hands back, which pages it hands back, and the two ways to write them out (#573).

One definition and not a facade copy of it, for the reason ProcessingLimits is re-exported rather than mirrored: a caller holding a Block from the facade and one from the engine must be holding the same type, or every consumer of both has to convert between two shapes that carry identical fields. The words as JSON lines, one object per word.

Each line is {"page", "block", "line", "word", "text", "bbox", "dir"} in the order crate::PdfDocument::extract_words hands the words back.