Module structure 

Flattening a document’s structural tree into an index-ordered list.

Pure and network-free, the way crate::drive::sheets::a1 is: this is the module where the subtle bugs live, so it must be testable without a wiremock server. body.content[] is a recursive forest — a table holds rows, which hold cells, which hold more structural elements, including more tables — and both drive docs info and drive docs read need it walked exactly once, the same way.

Two rules govern the walk and both matter:

• A container is emitted before its contents. A table yields one ElementKind::Table element carrying the table’s own [start, end) — which is what addresses the whole table — followed by each cell’s paragraphs. Without the container, a table is invisible in the flat list except as an unexplained index gap.
• Text is trimmed of its paragraph terminator; indices never are. Every Docs paragraph’s final textRun ends in \n, and that newline occupies one index unit. Rendering it would put a blank line after every row; subtracting it from end_index would make the reported indices lie about the document. So exactly one of the two is adjusted.

This module deliberately computes no index of its own — it only reports what the server sent. Docs indices are UTF-16 code units and Rust strings are UTF-8, so any index derived here would be wrong for astral-plane characters in a way that corrupts silently rather than failing. The write path avoids the problem the same way, by addressing insertions with endOfSegmentLocation rather than a number.

Structs

DocElement

One structural element, flattened out of the document tree.

Heading

A heading paragraph, for the docs info outline.

TabOutline

Aggregate counts and the heading outline for one tab.

Enums

ElementKind

What kind of thing a flattened element is.

Functions

flatten

Walks body.content depth-first, emitting every structural element in document-index order, containers before their contents.

flatten_content

Like flatten, but over a bare content slice rather than a Body.

outline

Counts and outlines one tab.