Found while testing crates/formula/src/printer.rs:164 (write_struct_ref, single column without specifiers)
Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Saving a large workbook spent about half its time building worksheet XML,
mostly in small per-cell allocations. The writer now appends to the part
directly:
- Cell references, row numbers, style ids, shared string indexes and
numbers are appended without temporary strings (push_a1, push_u64,
push_num), and text is escaped in place (push_esc, with a fast path for
plain ASCII).
- sheetData walks the cell store in its own row-major order instead of
copying every address into a BTreeSet and a per-row BTreeMap and looking
each cell up again. Cells outside the store (pictures, spill values,
table headers) still go through the sorted set.
- Formulas with nothing the file spells differently (no LET/LAMBDA, no
_xlfn function, no spill, @, trim operator or structured reference) are
printed from the shared expression instead of being cloned and rebuilt
twice by the file rewrite.
- The A1 printer in gridcraft-formula appends references to the output
instead of formatting each anchor into its own string.
The output is byte-for-byte unchanged.
write_perf, 200,000 rows (2.0M cells, 14.2 MB package), release, Ryzen
16 threads / Linux, 36 interleaved runs each:
before: median 2083.9 ms, min 1615.7 ms
after: median 1501.3 ms, min 1192.3 ms (-28.0 % median, -26.2 % min)
What remains is mostly deflate (zlib-rs, level 6), about 70 % of the save.
Tests pin the exact sheetData of a workbook covering row settings between
cell rows, spill values, every value kind, number spellings, escaping and
formulas with and without a file spelling (generated with the previous
writer), and check each appending helper and the formula fast path against
the code they replace.
The formula fast path is guarded by a test that runs both paths over every
function in the gridcraft-functions registry (a new dev-dependency, allowed
by the layer rules), in 15 surrounding shapes covering every operator and
rewrite, so a function or rewrite added later without updating the trigger
list fails it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Sheet1!A1:SHEET1!B2 is a range whose second end repeats the sheet, as
Sheet1!A1:Sheet1!B2 is: the check uses same_name, Excel's case-insensitive
name comparison.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Found while testing crates/formula/src/parser.rs (reference/sheet-prefix parsing) with crates/formula/src/printer.rs
Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
`=1+` reported "unexpected `)`", although no `)` was typed: entry closes
missing parentheses by appending up to eight `)`, and when every retry
failed it reported the last retry's error. It now reports the error of
the formula as typed ("unexpected end of formula").
`gridcraft_formula::parse_closing_parens` holds the convenience and takes
the parse function, so cell entry and the UI's Spanish formula path share
it instead of each having its own loop.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The left end of a flat operator chain is not nesting, so (((...1)))+1 is
accepted whenever (((...1))) is, in Spanish entry and display.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
along: =1+1+... with 4,096 operands (8,192 characters, exactly Excel's
limit, which Excel accepts and calculates) overflowed the stack when
entered, because the derived Clone of Expr recursed once per operand
down the chain's left spine. Saving hit the same in the XLSX writer.
- Expr: Clone, PartialEq, walk and map follow the left spine in a loop
and recurse only into right operands and real nesting.
- XLSX: _xlpm. prefixing and the implicit-intersection scan follow the
spine too. The scan's depth limit of 64 wrote any chain of more than
about 64 operands as a dynamic-array formula; such sums are plain
formulas again (ranges in the chain still get array evaluation).
- Evaluate Formula borrows sub-expressions instead of cloning each
operator's subtree (quadratic memory on a long chain).
- Spanish formula entry and display no longer refuse chains of more
than 256 operands; the left spine does not count as nesting.
Tests run on a 1 MiB stack (the Windows main thread) with Excel's
observed results: formula (clone/eq/walk/map/adjust at 4,096), calc
(401 and 4,096 operands, -, *, /, ^, &, %, comparisons, 1,500 refs),
xlsx (long chains written as scalar formulas), engine (cell.set, fill,
copy/paste, insert rows/columns, undo/redo, Evaluate Formula, XLSX save
and reopen), Spanish entry. Each fails without the fix.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A hostile file could abort any process that opens it: a cell formula of a
million `%` (`1%%%…`) or a 200,000-term sum parsed into trees deep enough to
overflow the stack when printed, saved, evaluated or dropped, even in release
builds. Postfix operators (`%`, invoking a result) built their nesting in a
loop that the 256-level limit did not see.
- `parse` refuses formula text longer than Excel's 8,192 characters
(`MAX_FORMULA_LEN`, counted in characters, the leading `=` excluded). This
also bounds the depth of the left-deep trees long operator chains build.
- Each postfix `%` and each call of a result counts towards the nesting limit.
- A file's formula that is refused keeps its text and cached value, as other
unparsable formulas do.
Regression tests: formula (small-stack thread: long `%`, invoke and operator
chains are errors; the limit counts characters, not bytes) and xlsx
(`hostile_formula_text_does_not_overflow_the_stack`: open, save and drop a
workbook with such formulas and a defined name on a 1 MiB stack). Both abort
with a stack overflow without the fix.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
- restore closing braces the line-level merges of side-by-side tests dropped
- new ChartData literals carry the palette field
- the filter-menu shortcut passes the row with the column
- #688's tab tests account for #851's All Sheets button
- Serbian margins for the ruler-margin labels
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The parser stripped _xludf. like _xlfn., but the two mean opposite things:
_xludf. marks a name Excel must not treat as a built-in. Keeping it in the
call name makes the call an unknown function (#NAME?, as in Excel) and the
writer emits it unchanged, so _xludf.EOMONTH() no longer saves as an
EOMONTH() call Excel repairs away.
Excel lets a worksheet function be passed by name where a function is
expected. In GridCraft GROUPBY(A2:A9,B2:B9,SUM) and PIVOTBY gave #NAME?
(their documented form), and BYROW, BYCOL, MAP, REDUCE, SCAN and
MAKEARRAY gave #VALUE!. A name that is a worksheet function, and not a
LET/LAMBDA variable or a defined name, now works as a function there.
Reading a file, the _xleta. prefix Excel writes for these names is
removed.
formula::parse("Sheet1!$D$1#") failed with "unknown error literal".
A # right after a cell reference is now the spill range operator: it
evaluates to the anchor's current spill range, or #REF! when the cell
doesn't spill (or its spill is blocked). Its users depend on the
anchor, so they recalculate when the spill grows or shrinks. Names can
use it.
Files have no # operator: like Excel, the writer stores A1# as
_xlfn.ANCHORARRAY(A1), and the parser reads that back as A1#.
Delete Cells built the references' edit and then discarded it, so
references into the deleted cells didn't become #REF!, and Insert Cells
treated the shift as a move of everything below, so =SUM(A1:A5) didn't
grow to A1:A6 when A3 was inserted.
Two new structural edits, InsertCells and DeleteCells, adjust a
reference like inserting/deleting rows (columns) when it lies within the
shifted columns (rows), and leave it as it is otherwise, as Excel does.
Formulas, defined names, chart series, conditional-format, validation,
table and print-area ranges, notes, links and sparklines follow.
- ui-egui: title bar with QAT, full ribbon (Home/Insert/Draw/Page Layout/Formulas/Data/
Review/View/Automate + Table/Chart Design), formula bar with Name Box, virtualised grid
(frozen panes, overflow, borders, CF data bars/scales/icons, tables, sparklines, filter
buttons, charts/pictures/shapes), in-cell editor with point mode, reference colouring,
autocomplete and argument hints, sheet tabs, status bar, dialogs, control channel
- apps/sheetcraft: desktop app (control server, file dialogs, prefs, drag & drop)
- chart: toolkit-free chart layout/rendering for 25 chart kinds + sparklines + rasteriser
- mcp + sheetcraft-cli: MCP server (headless or bridged) and CLI (info/convert/eval/cat/run/mcp)
- xtask (ci/layers/assets/wasm/version/parity), release workflows, packaging, placeholder icon
- automatic row heights
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
