Crate packdiff_wasm 

WASM ABI over packdiff-dto — the comment engine the generated HTML page calls into. Every model mutation and export the browser performs goes through here; the page’s JavaScript is only a view layer.

ABI (no wasm-bindgen, empty import object, works from file://):

• Strings cross the boundary as (ptr: u32, len: u32) UTF-8 buffers. JS allocates inputs with pd_alloc, writes, calls, then frees them with pd_free.
• Every API function returns a packed u64 = (ptr << 32) | len naming a fresh UTF-8 buffer the CALLER must free with pd_free after copying.
• Every returned buffer is a single-key union document (§ house style): { "Ok": <result> } on success or { "Error": { "message": "…" } } on failure. The Ok payload is a document object for mutations and a plain string for exports/keys.

Purity: the module has no clock and no entropy — comment ids and RFC 3339 timestamps come in from JS as part of the comment JSON.

Functions

pd_alloc

Allocate len bytes for the caller to write an input buffer into.

pd_delete_comment

Delete a comment by id (the id arrives as a plain UTF-8 string, not JSON). Returns the updated document; deleting a missing id is not an error.

pd_export_csv

pd_export_json

pd_export_markdown

pd_free

Free a buffer previously returned by pd_alloc or by any API function.

pd_markdown_html

Render markdown to safe HTML (the subset in packdiff_dto::markdown). The input is the raw markdown text — a plain UTF-8 string, not JSON — and Ok carries the HTML string. Never fails on any input.

pd_merge

Merge an imported document into the current one (union by id, newer updated_at wins). Returns the merged document.

pd_new_document

meta = {"repo": "...", "base": {"name","sha"}, "head": {"name","sha"}}. Returns a fresh empty review document.

pd_parse_document

Parse, validate, and normalize a stored document (the load path).

pd_range_diff

Diff a contiguous commit sub-range from the page’s embedded snapshots. snapshots is a RangeSnapshots JSON; params is {"from": <boundary index>, "to": <boundary index>, "context": N} with from < to (commit k alone is from = k - 1, to = k). Ok carries the FileDiff array — the same shape the build-time parser emits.

pd_storage_key

meta as in pd_new_document; returns the localStorage key string.

pd_upsert_comment

Insert or replace (by id) one comment. Returns the updated document.