AND/OR/NOT, Fehler-Literale und Zeilen/Spalten einfügen/löschen

- AND(...)/OR(...)/NOT(...) als gewöhnliche Funktionen (kein Kurzschluss-
  Sonderfall wie IF/XLOOKUP nötig, werten wie in echtem Excel alle
  Argumente eager aus). Dabei die bisher dreifach duplizierte
  Wahrheits-Prüfung zu functions.ts#isTruthy() zusammengezogen, jetzt
  von FUNCTIONS.IF, evalIf() und dem Block-IF-Statement gemeinsam genutzt.
  Schließt "kein AND/OR für zusammengesetzte Bedingungen" aus den
  Bekannten Grenzen, auch nutzbar in "Mit Schleife"-IF-Bedingungen.

- Neue Grammatik-Ergänzung: ErrorLiteralNode. Jeder der sieben Fehlercodes
  (#REF, #DIV/0!, #NAME?, #ERR, #CIRC, #VALUE!, #N/A) lässt sich jetzt
  direkt in eine Formel tippen (=IF(A1=0;#N/A;A1)) und wertet unbedingt zu
  genau diesem Fehler aus.

- Zeilen/Spalten einfügen/löschen mitten im Gitter (Rechtsklick auf einen
  Zeilen-/Spaltenkopf), nicht nur am Rand wie bisher: Zellinhalte, Formate
  und Zeilenhöhen/Spaltenbreiten verschieben sich innerhalb der Tabelle,
  und jede Formel im gesamten Dokument, die die Tabelle referenziert (auch
  über Tabelle!Zelle/Blatt!Tabelle::Zelle-Qualifier aus anderen Tabellen),
  wird automatisch mitgezogen. Ein Bereich, der die Stelle überspannt,
  wächst/schrumpft entsprechend; eine Referenz, die exakt die gelöschte
  Zeile/Spalte trifft, wird zu einem echten #REF-Literal im Formeltext
  (nutzt die neue ErrorLiteralNode-Grammatik). $-Sperren bleiben dabei
  bewusst wirkungslos (anders als beim Kopieren), unveränderte Referenzen
  bleiben byte-identisch. Token-Level-Splice wie shiftFormula (Kopieren/
  Ausschneiden), keine AST-Neuserialisierung.

406 Tests, vue-tsc/eslint/build sauber, Playwright-live-verifiziert.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/components/TableGrid.vue

@@ -952,13 +952,44 @@ function onKeydown(e: KeyboardEvent) {
 
 // ---- context menu -----------------------------------------
 const menu = ref({ x: 0, y: 0, open: false });
+/** Which row/col header (if any) the menu was opened on -- drives whether
+ *  it shows the row/col insert-delete items (Excel-style, only from a
+ *  header right-click) or the ordinary cell menu. */
+const menuCtx = ref<{ row: number | null; col: number | null }>({ row: null, col: null });
 function onContextMenu(e: MouseEvent) {
+  const target = e.target as HTMLElement | null;
+  const rowHeadEl = target?.closest?.('th[data-rowhead]') as HTMLElement | null;
+  const colHeadEl = target?.closest?.('th[data-colhead]') as HTMLElement | null;
+  menuCtx.value = {
+    row: rowHeadEl ? Number(rowHeadEl.dataset.rowhead) : null,
+    col: colHeadEl ? Number(colHeadEl.dataset.colhead) : null,
+  };
   const hit = cellFromEvent(e);
   // keep a multi-selection if the click landed inside it; otherwise select the cell
   if (hit && !inSelection(hit.c, hit.r)) select(hit.c, hit.r);
   menu.value = { x: e.clientX, y: e.clientY, open: true };
 }
 const menuItems = computed(() => {
+  const t = table.value;
+  const ctx = menuCtx.value;
+  if (t && ctx.row !== null) {
+    const r = ctx.row;
+    const items = [
+      { label: 'Zeile oberhalb einfügen', action: () => store.insertRow(props.tableId, r) },
+      { label: 'Zeile unterhalb einfügen', action: () => store.insertRow(props.tableId, r + 1) },
+    ];
+    if (t.rows > 1) items.push({ label: 'Zeile löschen', action: () => store.deleteRow(props.tableId, r) });
+    return items;
+  }
+  if (t && ctx.col !== null) {
+    const c = ctx.col;
+    const items = [
+      { label: 'Spalte links einfügen', action: () => store.insertColumn(props.tableId, c) },
+      { label: 'Spalte rechts einfügen', action: () => store.insertColumn(props.tableId, c + 1) },
+    ];
+    if (t.cols > 1) items.push({ label: 'Spalte löschen', action: () => store.deleteColumn(props.tableId, c) });
+    return items;
+  }
   const items = [
     { label: 'Kopieren', action: () => store.copySelection() },
     { label: 'Ausschneiden', action: () => store.cutSelection() },
@@ -1061,6 +1092,7 @@ defineExpose({
               v-for="c in table.cols"
               :key="'h' + (c - 1)"
               class="col-head"
+              :data-colhead="c - 1"
               :class="{ hot: colHot(c - 1), 'freeze-edge-right': c - 1 === frozenCols - 1 }"
               :style="c - 1 < frozenCols ? { left: colLeft(c - 1) + 'px', zIndex: '7' } : {}"
               @click="selectColumn(c - 1, $event)"
@@ -1074,6 +1106,7 @@ defineExpose({
           <tr v-for="r in table.rows" :key="'r' + (r - 1)" :style="{ height: rowH(r - 1) + 'px' }">
             <th
               class="row-head"
+              :data-rowhead="r - 1"
               :class="{ hot: rowHot(r - 1), 'frozen-row': r - 1 < frozenRows, 'freeze-edge-bottom': r - 1 === frozenRows - 1 }"
               :style="rowHeadStyle(r - 1)"
               @click="selectRow(r - 1, $event)"

src/engine/README.md

@@ -55,6 +55,7 @@ power       = primary [ "^" unary ] ;               (* rechts-assoziativ; bindet
                                                        -2^2 = -(2^2) = -4        *)
 primary     = NUMBER
             | STRING
+            | ERRORLIT
             | "(" expression ")"
             | funcall
             | reference
@@ -85,6 +86,9 @@ STRING      = /" ... "/  (Backslash-Escapes) ;
 IDENT       = /[A-Za-z_][A-Za-z0-9_]*/ ;
 QUOTED      = /' ( [^'] | '' )* '/     (* Tabellenname mit Leer-/Sonderzeichen *)
 CELL        = /\$?[A-Za-z]{1,3}\$?[0-9]{1,7}/ ;
+ERRORLIT    = "#REF" | "#DIV/0!" | "#NAME?" | "#ERR" | "#CIRC" |
+              "#VALUE!" | "#N/A" ;    (* longest-match in the lexer -- see
+                                         lexer.ts's ERROR_CODES_BY_LENGTH *)
 ```
 
 Präzedenz, schwach → stark: Vergleich (`= <> > < >= <=`)  <  `&`  <  `+ -`  <  `* /`  <  unäres `+ -`  <  `^`.
@@ -417,6 +421,16 @@ dagegen erlaubt), `blockAlwaysReturns` sowie die Zyklus-Prüfung.
   Konvention wie bei `kind: 'block'`s `IF`-Abhängigkeiten (s. u.). Ein
   benutzerdefiniertes „IF" ist nicht anlegbar (Namenskollision mit dem
   eingebauten `FUNCTIONS.IF`-Eintrag).
+- **`AND`/`OR`/`NOT` brauchen dagegen keine Sonderbehandlung** — anders als
+  `IF`/`XLOOKUP` sind es ganz normale `functions.ts`-Einträge, ohne
+  `evaluator.ts`-Kurzschluss: `AND`/`OR` werten (wie in echtem Excel) **alle**
+  Argumente eager aus, ein Fehler in irgendeinem Argument propagiert also
+  immer, egal ob das logische Ergebnis schon feststeht (`=AND(1=2; 1/0)` →
+  `#DIV/0!`, nicht `0`). `functions.ts#isTruthy()` ist die eine
+  Wahrheits-Konvention, die überall im Motor geteilt wird, wo eine Bedingung
+  gebraucht wird – `evalIf()` und `execStatement`s `ifstmt`-Fall importieren
+  sie jetzt aus `functions.ts`, statt sie (wie vor diesem Feature) je einmal
+  inline zu duplizieren.
 
 ## Datum & Zeit
 
@@ -558,3 +572,13 @@ rufen `rebuild()` für einen vollständigen – trotzdem billigen – Durchlauf.
 
 Es gibt **keinen** Absturz und **keinen** Hang: Lexer/Parser werfen intern,
 `Workbook` fängt alles ab und schreibt einen Fehlerwert in die Zelle.
+
+Jeder dieser sieben Codes ist außerdem als **`ErrorLiteralNode`** direkt in
+eine Formel tippbar (`=#REF`, `=IF(A1=0;#N/A;A1)`, …) – der Lexer erkennt
+ihn als eigenes `ERRORLIT`-Token (längster Treffer zuerst, s. o. EBNF),
+`evalScalar`s `case 'errorliteral':` gibt unbedingt `new FormulaError(code)`
+zurück. `store/document.ts`s Zeilen-/Spalten-Löschen ist der eine Ort, der
+selbst *Formeltext* mit `#REF`-Literalen erzeugt (für eine dadurch
+kollabierte Referenz) – ansonsten ist es reine Nutzer-Eingabe, wie eine
+Zahl- oder Text-Konstante. Kein `!` am Ende (`#REF`, nicht Excels `#REF!`)
+– derselbe Code, den diese Engine selbst überall sonst produziert.

src/engine/__tests__/evaluator.spec.ts

@@ -136,6 +136,74 @@ describe('evaluator IF', () => {
   });
 });
 
+describe('evaluator AND/OR/NOT', () => {
+  const host = makeHost({ S1: { A1: 8, B1: 0, C1: 'x' } });
+
+  it('AND is true only when every argument is truthy', () => {
+    expect(ev('=AND(1;1;1)', host)).toBe(1);
+    expect(ev('=AND(1;0;1)', host)).toBe(0);
+    expect(ev('=AND(A1>0;A1<10)', host)).toBe(1);
+    expect(ev('=AND(A1>0;A1<5)', host)).toBe(0);
+  });
+
+  it('OR is true when at least one argument is truthy', () => {
+    expect(ev('=OR(0;0;1)', host)).toBe(1);
+    expect(ev('=OR(0;0;0)', host)).toBe(0);
+  });
+
+  it('NOT inverts a single condition', () => {
+    expect(ev('=NOT(1)', host)).toBe(0);
+    expect(ev('=NOT(0)', host)).toBe(1);
+    expect(ev('=NOT(B1=0)', host)).toBe(0);
+  });
+
+  it('a range argument checks every cell (Excel behaviour)', () => {
+    const h = makeHost({ S1: { A1: 1, A2: 1, A3: 0 } });
+    expect(ev('=AND(A1:A3)', h)).toBe(0);
+    expect(ev('=OR(A1:A3)', h)).toBe(1);
+  });
+
+  it('empty cell and non-empty text follow the shared truthy convention', () => {
+    expect(ev('=AND(Z9)', host)).toBe(0); // empty cell -> falsy
+    expect(ev('=AND(C1)', host)).toBe(1); // non-empty text -> truthy
+  });
+
+  it('composes inside IF, unlike a bare chained comparison', () => {
+    expect(ev('=IF(AND(A1>0;A1<10);"ok";"nein")', host)).toBe('ok');
+  });
+
+  it('does NOT short-circuit -- every argument is evaluated, same as real Excel', () => {
+    expect(isError(ev('=AND(1=2;1/0)', host))).toBe(true);
+    expect(isError(ev('=OR(1=1;1/0)', host))).toBe(true);
+  });
+
+  it('wrong arity -> #ERR', () => {
+    expect(isError(ev('=AND()', host))).toBe(true);
+    expect(isError(ev('=NOT(1;2)', host))).toBe(true);
+    expect(isError(ev('=NOT()', host))).toBe(true);
+  });
+});
+
+describe('evaluator error literals (ErrorLiteralNode)', () => {
+  const host = makeHost({ S1: {} });
+
+  it('evaluates directly to that FormulaError', () => {
+    const r = ev('=#REF', host);
+    expect(isError(r) && r.code).toBe('#REF');
+  });
+
+  it('propagates through arithmetic like any other error', () => {
+    const r = ev('=1+#DIV/0!', host);
+    expect(isError(r) && r.code).toBe('#DIV/0!');
+  });
+
+  it('usable as an IF branch, e.g. a deliberate #N/A', () => {
+    expect(ev('=IF(1=0;#N/A;5)', host)).toBe(5);
+    const r = ev('=IF(1=1;#N/A;5)', host);
+    expect(isError(r) && r.code).toBe('#N/A');
+  });
+});
+
 describe('evaluator comparisons', () => {
   const host = makeHost({ S1: { A1: 'Nord', B1: 5 } });
 

src/engine/__tests__/lexer.spec.ts

@@ -89,4 +89,27 @@ describe('lexer', () => {
     expect(types('A1<B2')).toEqual(['IDENT', 'LT', 'IDENT', 'EOF']);
     expect(types('A1>B2')).toEqual(['IDENT', 'GT', 'IDENT', 'EOF']);
   });
+
+  it('tokenizes every error code as one ERRORLIT token', () => {
+    expect(types('#REF')).toEqual(['ERRORLIT', 'EOF']);
+    expect(values('#REF')).toEqual(['#REF', '']);
+    expect(types('#DIV/0!')).toEqual(['ERRORLIT', 'EOF']);
+    expect(types('#NAME?')).toEqual(['ERRORLIT', 'EOF']);
+    expect(types('#ERR')).toEqual(['ERRORLIT', 'EOF']);
+    expect(types('#CIRC')).toEqual(['ERRORLIT', 'EOF']);
+    expect(types('#VALUE!')).toEqual(['ERRORLIT', 'EOF']);
+    expect(types('#N/A')).toEqual(['ERRORLIT', 'EOF']);
+  });
+
+  it('an ERRORLIT is followed by whatever comes next, not swallowed into it', () => {
+    expect(types('1+#REF')).toEqual(['NUMBER', 'PLUS', 'ERRORLIT', 'EOF']);
+    // "#REF" matches greedily -- a trailing "!" some might expect (Excel
+    // spells it "#REF!") is its own BANG token, not part of the literal;
+    // this engine's own error code is "#REF" without "!" (see types.ts).
+    expect(types('#REF!')).toEqual(['ERRORLIT', 'BANG', 'EOF']);
+  });
+
+  it('throws on an unrecognized "#..." sequence', () => {
+    expect(() => tokenize('#FOO')).toThrow();
+  });
 });

src/engine/__tests__/parser.spec.ts

@@ -16,6 +16,8 @@ function sexpr(n: Node): string {
       return String(n.value);
     case 'string':
       return JSON.stringify(n.value);
+    case 'errorliteral':
+      return n.code;
     case 'unary':
       return `(${n.op} ${sexpr(n.operand)})`;
     case 'binary':
@@ -242,6 +244,23 @@ describe('parser named-range references (NamedRefNode)', () => {
   });
 });
 
+describe('parser error literals (ErrorLiteralNode)', () => {
+  it('every error code parses as a leaf', () => {
+    expect(parse('=#REF')).toBe('#REF');
+    expect(parse('=#DIV/0!')).toBe('#DIV/0!');
+    expect(parse('=#NAME?')).toBe('#NAME?');
+    expect(parse('=#ERR')).toBe('#ERR');
+    expect(parse('=#CIRC')).toBe('#CIRC');
+    expect(parse('=#VALUE!')).toBe('#VALUE!');
+    expect(parse('=#N/A')).toBe('#N/A');
+  });
+
+  it('composes with operators/functions like any other literal', () => {
+    expect(parse('=1+#REF')).toBe('(+ 1 #REF)');
+    expect(parse('=IF(1=0;#N/A;5)')).toBe('(IF (= 1 0) #N/A 5)');
+  });
+});
+
 describe('parser comparison operators (available in every formula, not just block IF conditions)', () => {
   it('parses all six comparison operators', () => {
     expect(parse('=A1=B1')).toBe('(= cell(0,0) cell(1,0))');

src/engine/__tests__/userFunctions.spec.ts

@@ -395,6 +395,21 @@ describe('Workbook integration: block-kind (FOR/IF/RETURN "code") user-defined f
     expect(val(wb, 's-umsatz', 'B9')).toBe(0);
   });
 
+  it('AND/OR compose a compound condition inside an IF, same as any other function call', () => {
+    const umsatz = sheet('s-umsatz', 'Umsatz', { A1: '5', B9: '=INRANGE(A1)' });
+    const inRange = def({
+      id: 'f1',
+      name: 'INRANGE',
+      params: ['x'],
+      kind: 'block',
+      body: 'IF AND(x > 0; x < 10) THEN RETURN 1 ELSE RETURN 0 END',
+    });
+    const wb = new Workbook([umsatz], [inRange]);
+    expect(val(wb, 's-umsatz', 'B9')).toBe(1);
+    wb.setCell('s-umsatz', 0, 0, '20'); // A1: 5 -> 20, out of range
+    expect(val(wb, 's-umsatz', 'B9')).toBe(0);
+  });
+
   it('an early RETURN nested inside an IF inside a FOR stops the loop -- finds the first match, never touches later cells', () => {
     // A3 is the first cell > 100; A4 must never affect the result
     const umsatz = sheet('s-umsatz', 'Umsatz', {

src/engine/evaluator.ts

@@ -40,7 +40,7 @@
  */
 
 import type { BlockCallNode, BlockNode, CellNode, FuncNode, NamedRefNode, Node, RangeNode, Statement } from './parser';
-import { getFunction } from './functions';
+import { getFunction, isTruthy } from './functions';
 import { expandRange } from './refs';
 import { substitute } from './userFunctions';
 import { FormulaError, isError, type CellValue, type EngineHost } from './types';
@@ -55,6 +55,8 @@ function evalScalar(node: Node, host: EngineHost): CellValue {
       return node.value;
     case 'string':
       return node.value;
+    case 'errorliteral':
+      return new FormulaError(node.code);
 
     case 'unary': {
       const v = toNumber(evalScalar(node.operand, host));
@@ -173,18 +175,17 @@ function evalScalar(node: Node, host: EngineHost): CellValue {
  *  comment). Only `node.args[0]` is always evaluated; whichever of the
  *  other two branches is taken is evaluated next, and the other is never
  *  touched at all -- so an error (or, in a block-mode call, any other side
- *  effect) in the untaken branch never surfaces. Same truthy convention as
- *  everywhere else in this engine (`execStatement`'s `ifstmt` case, above):
- *  a number is truthy unless it's exactly 0; text/refs are truthy unless
- *  empty. */
+ *  effect) in the untaken branch never surfaces. Truthy via functions.ts's
+ *  `isTruthy()` -- the one convention shared everywhere in this engine a
+ *  condition is needed (also `execStatement`'s `ifstmt` case, below, and
+ *  `AND`/`OR`/`NOT`). */
 function evalIf(node: FuncNode, host: EngineHost): CellValue {
   if (node.args.length !== 2 && node.args.length !== 3) {
     return new FormulaError('#ERR', 'IF expects 2 or 3 arguments');
   }
   const cond = evalScalar(node.args[0], host);
   if (isError(cond)) return cond;
-  const truthy = typeof cond === 'number' ? cond !== 0 : cond !== null && cond !== '';
-  if (truthy) return evalScalar(node.args[1], host);
+  if (isTruthy(cond)) return evalScalar(node.args[1], host);
   return node.args.length === 3 ? evalScalar(node.args[2], host) : 0;
 }
 
@@ -403,8 +404,7 @@ function execStatement(
     case 'ifstmt': {
       const c = evalInEnv(stmt.cond, env, host);
       if (isError(c)) throw new ReturnSignal(c);
-      const truthy = typeof c === 'number' ? c !== 0 : c !== null && c !== '';
-      if (truthy) execBlock(stmt.then, env, host, budget);
+      if (isTruthy(c)) execBlock(stmt.then, env, host, budget);
       else if (stmt.else) execBlock(stmt.else, env, host, budget);
       return;
     }

src/engine/functions.ts

@@ -27,6 +27,17 @@ function nums(values: CellValue[]): number[] {
   return out;
 }
 
+/** The one truthy convention used everywhere in this engine a condition is
+ *  needed (IF's condition -- both the formula function and its real
+ *  short-circuit implementation in evaluator.ts's evalIf() --, a "Mit
+ *  Schleife" block's IF statement, and AND/OR/NOT below): a number is
+ *  truthy unless it's exactly `0`; text is truthy unless empty; an empty
+ *  cell (`null`) is never truthy. Exported so evaluator.ts can reuse the
+ *  exact same rule instead of duplicating it. */
+export function isTruthy(v: CellValue): boolean {
+  return typeof v === 'number' ? v !== 0 : v !== null && v !== '';
+}
+
 export const FUNCTIONS: Record<string, FunctionFn> = {
   SUM(values) {
     return nums(values).reduce((a, b) => a + b, 0);
@@ -78,11 +89,30 @@ export const FUNCTIONS: Record<string, FunctionFn> = {
     }
     const [cond, thenValue, elseValue] = values;
     if (isError(cond)) return cond;
-    const truthy = typeof cond === 'number' ? cond !== 0 : cond !== null && cond !== '';
-    if (truthy) return thenValue;
+    if (isTruthy(cond)) return thenValue;
     return values.length === 3 ? elseValue : 0;
   },
 
+  // Ordinary (non-short-circuit) functions -- like real Excel, EVERY
+  // argument is evaluated regardless of the others (so e.g.
+  // =AND(1=2; 1/0) is still #DIV/0!, not FALSE, exactly as in Excel) --
+  // no special-casing in evaluator.ts needed, unlike IF/XLOOKUP. A range
+  // argument flattens into one truthy check per cell, same as Excel.
+  AND(values) {
+    if (values.length === 0) return new FormulaError('#ERR', 'AND expects at least 1 argument');
+    return values.every(isTruthy) ? 1 : 0;
+  },
+
+  OR(values) {
+    if (values.length === 0) return new FormulaError('#ERR', 'OR expects at least 1 argument');
+    return values.some(isTruthy) ? 1 : 0;
+  },
+
+  NOT(values) {
+    if (values.length !== 1) return new FormulaError('#ERR', 'NOT expects exactly 1 argument');
+    return isTruthy(values[0]) ? 0 : 1;
+  },
+
   // Dates/times are plain numbers here (see dates.ts) -- DATE/TIME build one,
   // TODAY/NOW read the current one. `null` (empty cell) arguments count as 0,
   // same as everywhere else in this engine; a non-numeric text argument is
@@ -169,6 +199,9 @@ export const BUILTIN_SIGNATURES: ReadonlyArray<{ name: string; hint: string }> =
   { name: 'CONCAT', hint: 'CONCAT(Text1; Text2; …)' },
   { name: 'CONCATENATE', hint: 'CONCATENATE(Text1; Text2; …)' },
   { name: 'IF', hint: 'IF(Bedingung; Dann; Sonst?)' },
+  { name: 'AND', hint: 'AND(Bedingung1; Bedingung2; …)' },
+  { name: 'OR', hint: 'OR(Bedingung1; Bedingung2; …)' },
+  { name: 'NOT', hint: 'NOT(Bedingung)' },
   { name: 'DATE', hint: 'DATE(Jahr; Monat; Tag)' },
   { name: 'TIME', hint: 'TIME(Std; Min; Sek)' },
   { name: 'TODAY', hint: 'TODAY()' },

src/engine/lexer.ts

@@ -8,11 +8,14 @@
  * them by look-ahead (`(` -> function, `!` -> sheet qualifier, digits -> cell).
  */
 
+import { ERROR_CODES } from './types';
+
 export type TokenType =
   | 'NUMBER'
   | 'STRING'
   | 'IDENT' // bare word: A1, SUM, Region, Q1 ...
   | 'QUOTED' // 'Kosten Q3' -- a sheet name in single quotes
+  | 'ERRORLIT' // a literal error code, e.g. "#REF" or "#DIV/0!" -- see ERROR_CODES
   | 'PLUS'
   | 'MINUS'
   | 'STAR'
@@ -74,6 +77,10 @@ function isWordPart(ch: string): boolean {
   return isWordStart(ch) || isDigit(ch);
 }
 
+/** Longest-first, so a prefix of another code (none collide today, but this
+ *  stays correct if one ever did) never wins the match by accident. */
+const ERROR_CODES_BY_LENGTH = [...ERROR_CODES].sort((a, b) => b.length - a.length);
+
 export function tokenize(src: string): Token[] {
   const tokens: Token[] = [];
   let i = 0;
@@ -182,6 +189,21 @@ export function tokenize(src: string): Token[] {
       continue;
     }
 
+    // an error-code literal, e.g. "#REF" or "#DIV/0!" -- lets a formula
+    // literally contain/produce one, same as typing it in Excel; also how a
+    // structural row/col delete marks a now-broken reference in formula text
+    // (see store/document.ts's row/col delete). Recognized as one token
+    // regardless of what follows (a subsequent "!"/"?" is already consumed
+    // as part of the matched code, never re-tokenized as BANG etc.).
+    if (ch === '#') {
+      const code = ERROR_CODES_BY_LENGTH.find((c) => src.startsWith(c, i));
+      if (code) {
+        tokens.push({ type: 'ERRORLIT', value: code, pos: i });
+        i += code.length;
+        continue;
+      }
+    }
+
     // single-character punctuation / operators
     const t = SINGLE[ch];
     if (t) {

src/engine/parser.ts

@@ -31,6 +31,7 @@
  *                                                          -2^2 = -(2^2) = -4  *)
  *   primary     = NUMBER
  *               | STRING
+ *               | ERRORLIT
  *               | "(" expression ")"
  *               | funcall
  *               | reference ;
@@ -63,6 +64,12 @@
  *                                                     (backward-compatible --
  *                                                     see reference() below). *)
  *   CELL        = /\$?[A-Za-z]{1,3}\$?[0-9]{1,7}/ ;
+ *   ERRORLIT    = "#REF" | "#DIV/0!" | "#NAME?" | "#ERR" | "#CIRC" |
+ *                 "#VALUE!" | "#N/A" ;                (* a literal error code,
+ *                                                        typed directly or
+ *                                                        produced by a
+ *                                                        structural row/col
+ *                                                        delete             *)
  *
  * Precedence, lowest to highest:  comparison   <   &   <   + -   <   * /   <   unary +/-   <   ^
  * ---------------------------------------------------------------------------
@@ -84,10 +91,12 @@
 
 import { tokenize, type Token, type TokenType, LexError } from './lexer';
 import { looksLikeCell, parseA1 } from './refs';
+import type { ErrorCode } from './types';
 
 export type Node =
   | NumberNode
   | StringNode
+  | ErrorLiteralNode
   | BinaryNode
   | UnaryNode
   | FuncNode
@@ -106,6 +115,16 @@ export interface StringNode {
   kind: 'string';
   value: string;
 }
+/** A literal error code typed directly into a formula, e.g. `=#REF!+1` or
+ *  `=IF(A1=0;#N/A;A1)` -- same as typing one in Excel. Evaluates directly to
+ *  that `FormulaError`, unconditionally (it's not the *result* of anything,
+ *  just a value like a number or string literal). Also how a structural
+ *  row/col delete represents a now-broken reference in stored formula text
+ *  (see store/document.ts). */
+export interface ErrorLiteralNode {
+  kind: 'errorliteral';
+  code: ErrorCode;
+}
 export interface BinaryNode {
   kind: 'binary';
   op: '+' | '-' | '*' | '/' | '^' | '&' | '=' | '<>' | '>' | '<' | '>=' | '<=';
@@ -487,6 +506,10 @@ class Parser {
       this.next();
       return { kind: 'string', value: t.value };
     }
+    if (t.type === 'ERRORLIT') {
+      this.next();
+      return { kind: 'errorliteral', code: t.value as ErrorCode };
+    }
     if (t.type === 'LPAREN') {
       this.next();
       const inner = this.expression();

src/engine/userFunctions.ts

@@ -91,6 +91,7 @@ function expand(
   switch (node.kind) {
     case 'number':
     case 'string':
+    case 'errorliteral':
     case 'cell':
     case 'range':
     case 'namedref':
@@ -179,6 +180,7 @@ export function substitute(node: Node, bound: ReadonlyMap<string, Node>): Node {
       return bound.get(node.name.toUpperCase()) ?? node;
     case 'number':
     case 'string':
+    case 'errorliteral':
     case 'cell':
     case 'range':
     case 'namedref':

src/store/__tests__/document.spec.ts

@@ -1003,6 +1003,236 @@ describe('named ranges (document-level names for a fixed cell/range)', () => {
   });
 });
 
+describe('insertRow/deleteRow/insertColumn/deleteColumn (mid-grid, not just edge growth)', () => {
+  const raw = (s: DocumentStore, table: string, a1: string) => {
+    const { col, row } = coords(a1);
+    return s.cellInput(tableId(s, table), col, row);
+  };
+
+  it('insertRow shifts cell data down from the insertion point, leaves earlier rows alone', () => {
+    const s = fresh();
+    const id = s.addTable(s.doc.activeSheetId);
+    const name = s.tableById(id)!.name;
+    setCell(s, name, 'A1', 'x');
+    setCell(s, name, 'A2', 'y');
+    s.insertRow(id, 1);
+    expect(val(s, name, 'A1')).toBe('x'); // row 0, before the insertion point -- untouched
+    expect(val(s, name, 'A2')).toBeNull(); // new empty row
+    expect(val(s, name, 'A3')).toBe('y'); // shifted down
+    expect(s.tableById(id)!.rows).toBe(13); // default 12 + 1
+  });
+
+  it('deleteRow removes that row and shifts the rest up', () => {
+    const s = fresh();
+    const id = s.addTable(s.doc.activeSheetId);
+    const name = s.tableById(id)!.name;
+    setCell(s, name, 'A1', 'x');
+    setCell(s, name, 'A2', 'y');
+    setCell(s, name, 'A3', 'z');
+    s.deleteRow(id, 1);
+    expect(val(s, name, 'A1')).toBe('x');
+    expect(val(s, name, 'A2')).toBe('z'); // 'y' is gone, 'z' shifted up
+    expect(s.tableById(id)!.rows).toBe(11);
+  });
+
+  it('deleteRow refuses to remove the last remaining row', () => {
+    const s = fresh();
+    const id = s.addTable(s.doc.activeSheetId);
+    const initialRows = s.tableById(id)!.rows;
+    for (let i = 0; i < initialRows - 1; i++) s.deleteRow(id, 0);
+    expect(s.tableById(id)!.rows).toBe(1);
+    s.deleteRow(id, 0);
+    expect(s.tableById(id)!.rows).toBe(1); // no-op, refused
+  });
+
+  it('insertColumn/deleteColumn mirror the row behaviour, incl. colWidths', () => {
+    const s = fresh();
+    const id = s.addTable(s.doc.activeSheetId);
+    const name = s.tableById(id)!.name;
+    setCell(s, name, 'A1', 'x');
+    setCell(s, name, 'B1', 'y');
+    s.setColWidth(id, 1, 111); // column B
+    s.insertColumn(id, 1);
+    expect(val(s, name, 'A1')).toBe('x');
+    expect(val(s, name, 'B1')).toBeNull();
+    expect(val(s, name, 'C1')).toBe('y'); // shifted right, width override moved with it
+    expect(s.tableById(id)!.colWidths[2]).toBe(111);
+
+    s.deleteColumn(id, 1); // remove the now-empty B
+    expect(val(s, name, 'A1')).toBe('x');
+    expect(val(s, name, 'B1')).toBe('y'); // shifted back left
+    expect(s.tableById(id)!.colWidths[1]).toBe(111);
+  });
+
+  it('a self-referencing formula (same table) is rewritten to keep pointing at the same logical cell', () => {
+    const s = fresh();
+    const id = s.addTable(s.doc.activeSheetId);
+    const name = s.tableById(id)!.name;
+    setCell(s, name, 'B5', '20');
+    setCell(s, name, 'C1', '=B5');
+    expect(val(s, name, 'C1')).toBe(20);
+
+    s.insertRow(id, 2); // B5 (row 4) shifts to B6; C1 (row 0) stays put
+    expect(raw(s, name, 'C1')).toBe('=B6');
+    expect(val(s, name, 'C1')).toBe(20);
+  });
+
+  it('a cross-table qualified reference is rewritten too, not just formulas inside the edited table', () => {
+    const s = fresh();
+    const src = s.addTable(s.doc.activeSheetId);
+    s.renameObject(src, 'Quelle');
+    const dst = s.addTable(s.doc.activeSheetId);
+    s.renameObject(dst, 'Ziel');
+    setCell(s, 'Quelle', 'B5', '42');
+    setCell(s, 'Ziel', 'A1', '=Quelle!B5');
+    expect(val(s, 'Ziel', 'A1')).toBe(42);
+
+    s.insertRow(src, 2);
+    expect(raw(s, 'Ziel', 'A1')).toBe('=Quelle!B6');
+    expect(val(s, 'Ziel', 'A1')).toBe(42);
+  });
+
+  it('a range that straddles the insertion point grows by one row instead of just sliding', () => {
+    const s = fresh();
+    const id = s.addTable(s.doc.activeSheetId);
+    const name = s.tableById(id)!.name;
+    setCell(s, name, 'B1', '1');
+    setCell(s, name, 'B2', '2');
+    setCell(s, name, 'B3', '3');
+    setCell(s, name, 'D1', '=SUM(B1:B3)');
+    expect(val(s, name, 'D1')).toBe(6);
+
+    s.insertRow(id, 1); // inside the range (row 1, between B1 and what was B2)
+    expect(raw(s, name, 'D1')).toBe('=SUM(B1:B4)'); // grew by one
+    setCell(s, name, 'B2', '99'); // the newly inserted row is now part of the range
+    expect(val(s, name, 'D1')).toBe(1 + 99 + 2 + 3);
+  });
+
+  it('a range fully after the deletion point shifts down, keeps its size', () => {
+    const s = fresh();
+    const id = s.addTable(s.doc.activeSheetId);
+    const name = s.tableById(id)!.name;
+    setCell(s, name, 'B2', '10');
+    setCell(s, name, 'B3', '20');
+    setCell(s, name, 'D5', '=SUM(B2:B3)'); // away from row 0, so it survives the delete itself
+    s.deleteRow(id, 0); // delete row 0, entirely before the range -- range shifts, doesn't shrink in size
+    expect(raw(s, name, 'D4')).toBe('=SUM(B1:B2)');
+    expect(val(s, name, 'D4')).toBe(30);
+  });
+
+  it('deleting a row *inside* a multi-row range shrinks it by one, keeps the rest', () => {
+    const s = fresh();
+    const id = s.addTable(s.doc.activeSheetId);
+    const name = s.tableById(id)!.name;
+    setCell(s, name, 'B1', '1');
+    setCell(s, name, 'B2', '2');
+    setCell(s, name, 'B3', '3');
+    setCell(s, name, 'D1', '=SUM(B1:B3)');
+    s.deleteRow(id, 1); // remove the middle row of the range
+    expect(raw(s, name, 'D1')).toBe('=SUM(B1:B2)');
+    expect(val(s, name, 'D1')).toBe(1 + 3); // only 1 and (shifted) 3 remain
+  });
+
+  it('a single-cell reference exactly on the deleted row becomes a literal #REF', () => {
+    const s = fresh();
+    const id = s.addTable(s.doc.activeSheetId);
+    const name = s.tableById(id)!.name;
+    setCell(s, name, 'B2', '10');
+    setCell(s, name, 'C1', '=B2+1');
+    s.deleteRow(id, 1); // row 1 is exactly B2's row
+    expect(raw(s, name, 'C1')).toBe('=#REF+1');
+    expect(isError(val(s, name, 'C1'))).toBe(true);
+  });
+
+  it('a range entirely on the deleted row collapses to a literal #REF', () => {
+    const s = fresh();
+    const id = s.addTable(s.doc.activeSheetId);
+    const name = s.tableById(id)!.name;
+    setCell(s, name, 'B2', '1');
+    setCell(s, name, 'D2', '2');
+    setCell(s, name, 'D1', '=SUM(B2:D2)'); // a 1-row range, entirely row 1
+    s.deleteRow(id, 1);
+    expect(raw(s, name, 'D1')).toBe('=SUM(#REF)');
+    expect(isError(val(s, name, 'D1'))).toBe(true);
+  });
+
+  it('a $-locked reference still shifts -- unlike copy/paste, $ has no effect on a structural insert/delete', () => {
+    const s = fresh();
+    const id = s.addTable(s.doc.activeSheetId);
+    const name = s.tableById(id)!.name;
+    setCell(s, name, 'B5', '7');
+    setCell(s, name, 'C1', '=$B$5');
+    s.insertRow(id, 1);
+    expect(raw(s, name, 'C1')).toBe('=$B$6');
+    expect(val(s, name, 'C1')).toBe(7);
+  });
+
+  it('a reference to a row before the insertion/deletion point is left untouched, byte-identical', () => {
+    const s = fresh();
+    const id = s.addTable(s.doc.activeSheetId);
+    const name = s.tableById(id)!.name;
+    setCell(s, name, 'A1', '5');
+    // lower-case + extra spacing in the formula text -- proves an untouched
+    // reference (row 0, nowhere near the insertion point at row 5) is left
+    // completely alone, not just numerically equivalent
+    setCell(s, name, 'C1', '=a1 + 1');
+    s.insertRow(id, 5);
+    expect(raw(s, name, 'C1')).toBe('=a1 + 1');
+    s.deleteRow(id, 5);
+    expect(raw(s, name, 'C1')).toBe('=a1 + 1');
+  });
+
+  it('the sheet-qualified 3-part form ("Blatt!Tabelle::Zelle") is resolved and rewritten too', () => {
+    const s = fresh();
+    // fresh sheets, names that don't collide with the seed's own "Analyse"/
+    // "Umsatz" (the whole point of the 3-part form is disambiguating a name
+    // used on more than one sheet, but that's not what this test is about)
+    const sheetA = s.addSheet();
+    s.renameSheet(sheetA, 'ErsterBogen');
+    const src = s.addTable(sheetA);
+    s.renameObject(src, 'Quelle3');
+    const sheetB = s.addSheet();
+    s.renameSheet(sheetB, 'ZweiterBogen');
+    const dst = s.addTable(sheetB);
+    s.renameObject(dst, 'Ziel3');
+
+    setCell(s, 'Quelle3', 'B5', '42');
+    setCell(s, 'Ziel3', 'A1', '=ErsterBogen!Quelle3::B5');
+    expect(val(s, 'Ziel3', 'A1')).toBe(42);
+
+    s.insertRow(src, 2);
+    expect(raw(s, 'Ziel3', 'A1')).toBe('=ErsterBogen!Quelle3::B6');
+    expect(val(s, 'Ziel3', 'A1')).toBe(42);
+  });
+
+  it('undo/redo covers a row insert/delete, incl. the document-wide formula rewrite', () => {
+    vi.useFakeTimers();
+    try {
+      const s = fresh();
+      const id = s.addTable(s.doc.activeSheetId);
+      const name = s.tableById(id)!.name;
+      setCell(s, name, 'B5', '10');
+      setCell(s, name, 'C1', '=B5');
+      vi.advanceTimersByTime(600);
+
+      s.insertRow(id, 2);
+      vi.advanceTimersByTime(600);
+      expect(raw(s, name, 'C1')).toBe('=B6');
+
+      s.undo();
+      expect(raw(s, name, 'C1')).toBe('=B5');
+      expect(s.tableById(id)!.rows).toBe(12);
+
+      s.redo();
+      expect(raw(s, name, 'C1')).toBe('=B6');
+      expect(s.tableById(id)!.rows).toBe(13);
+    } finally {
+      vi.runOnlyPendingTimers();
+      vi.useRealTimers();
+    }
+  });
+});
+
 describe('functionSuggestions (formula autocomplete)', () => {
   it('filters built-ins by prefix, case-insensitively', () => {
     const s = fresh();

src/store/document.ts

@@ -203,6 +203,203 @@ function shiftFormula(raw: string, dCol: number, dRow: number, restrict?: Rect):
   return '=' + out;
 }
 
+// ---- row/col insert & delete: document-wide reference rewriting ---------
+// A mid-grid row/col insert/delete (unlike edge growth/shrink, or copy/paste's
+// shiftFormula above) can invalidate/relocate references from *any* formula
+// in the *whole document*, not just the edited table's own -- another table's
+// `Tabelle!Zelle` qualifier can point straight at it. `rewriteRefsForStructuralChange`
+// below is the token-level rewriter that does that (same splice technique as
+// shiftFormula: only the affected cell/range tokens' exact text is touched,
+// everything else -- including whitespace -- is byte-identical); it's the
+// engine used by `insertRow`/`deleteRow`/`insertColumn`/`deleteColumn` (in the
+// store proper, below) via `rewriteDocumentRefs`.
+
+type Axis = 'row' | 'col';
+
+/** Insert-side shift for one coordinate: everything at/after `at` moves by
+ *  +1. Applied independently to a single cell and to each range endpoint --
+ *  for a range straddling `at` (start < at <= end), only the end moves, so
+ *  the range *grows* by one to include the newly inserted row/col (the same
+ *  behaviour Excel has for "insert a row inside a SUM range"). */
+function insertShift(v: number, at: number): number {
+  return v >= at ? v + 1 : v;
+}
+/** Delete-side shift for a range's *start* endpoint: `at` itself stays `at`
+ *  (the next surviving row/col slides into that slot); only something
+ *  strictly after `at` moves down by one. */
+function deleteShiftStart(v: number, at: number): number {
+  return v > at ? v - 1 : v;
+}
+/** Delete-side shift for a range's *end* endpoint: unlike the start
+ *  endpoint, `at` itself also moves down by one here -- that row/col is
+ *  gone, so the range's last surviving row/col is one less than before. */
+function deleteShiftEnd(v: number, at: number): number {
+  return v >= at ? v - 1 : v;
+}
+
+function axisValue(axis: Axis, c: { col: number; row: number }): number {
+  return axis === 'row' ? c.row : c.col;
+}
+function withAxisValue(
+  axis: Axis,
+  c: { col: number; row: number; colAbs: boolean; rowAbs: boolean },
+  v: number,
+): string {
+  return axis === 'row' ? toA1(c.col, v, c.colAbs, c.rowAbs) : toA1(v, c.row, c.colAbs, c.rowAbs);
+}
+
+/** True iff, with `toks[i]` a known "!" (BANG), the shape ahead is
+ *  IDENT/QUOTED "::" -- i.e. this "!" really introduces a SHEET name
+ *  followed by a table qualifier (the 3-part `Blatt!Tabelle::Zelle` form),
+ *  not a bare (old-style) table qualifier of its own. Exact same lookahead
+ *  as `parser.ts#Parser.looksLikeSheetThenTable`. */
+function looksLikeSheetThenTable(toks: Token[], i: number): boolean {
+  const n1 = toks[i + 1];
+  const n2 = toks[i + 2];
+  return !!n1 && (n1.type === 'IDENT' || n1.type === 'QUOTED') && !!n2 && n2.type === 'DBLCOLON';
+}
+
+/**
+ * Rewrite every reference to `targetTableId` inside one formula for a
+ * structural row/col insert (`delta` `1`) or delete (`delta` `-1`) at index
+ * `at` on `axis`. `homeTableId` is the formula's *own* table (needed to
+ * resolve a bare, unqualified reference, and -- via a transiently-set
+ * `wb.homeTableId` -- to break a same-table-name-on-two-sheets ambiguity
+ * the exact same way `wb.resolveTableName` already does for evaluation;
+ * this function literally calls it).
+ *
+ * A reference landing exactly on a deleted row/col -- or a range that
+ * collapses entirely (every row/col it covered was the one deleted) --
+ * becomes a literal `#REF` (see engine/parser.ts's `ErrorLiteralNode`),
+ * the same thing Excel shows inline for a broken reference. A range that
+ * merely *shrinks* (only part of it was the deleted line) stays a valid,
+ * smaller range, exactly like Excel.
+ */
+function rewriteRefsForStructuralChange(
+  raw: string,
+  homeTableId: string,
+  targetTableId: string,
+  axis: Axis,
+  at: number,
+  delta: 1 | -1,
+  wb: Workbook,
+): string {
+  if (!raw.startsWith('=')) return raw;
+  const body = raw.slice(1);
+  let toks: Token[];
+  try {
+    toks = tokenize(body);
+  } catch {
+    return raw; // unparsable -- leave as-is, the evaluator already surfaces #ERR
+  }
+
+  const savedHome = wb.homeTableId;
+  wb.homeTableId = homeTableId;
+  const resolve = (name: string, sheetName: string | null): string | null =>
+    wb.resolveTableName(name, sheetName);
+
+  interface Repl {
+    pos: number;
+    end: number;
+    text: string;
+  }
+  const repls: Repl[] = [];
+
+  let i = 0;
+  while (i < toks.length && toks[i].type !== 'EOF') {
+    const tok = toks[i];
+    let cellIdx = -1;
+    let resolvedTableId: string | null = null;
+
+    if ((tok.type === 'IDENT' || tok.type === 'QUOTED') && toks[i + 1]) {
+      if (toks[i + 1].type === 'BANG' && looksLikeSheetThenTable(toks, i + 1)) {
+        resolvedTableId = resolve(toks[i + 2].value, tok.value); // sheet=tok, table=toks[i+2]
+        cellIdx = i + 4; // consumed: IDENT/QUOTED "!" IDENT/QUOTED "::"
+      } else if (toks[i + 1].type === 'BANG' || toks[i + 1].type === 'DBLCOLON') {
+        resolvedTableId = resolve(tok.value, null);
+        cellIdx = i + 2;
+      }
+    }
+    if (cellIdx === -1 && tok.type === 'IDENT' && looksLikeCell(tok.value)) {
+      resolvedTableId = homeTableId;
+      cellIdx = i;
+    }
+    if (cellIdx === -1) {
+      i++;
+      continue;
+    }
+
+    const cellTokA = toks[cellIdx];
+    if (!cellTokA || cellTokA.type !== 'IDENT' || !looksLikeCell(cellTokA.value)) {
+      i++; // qualifier not actually followed by a cell -- malformed, leave alone
+      continue;
+    }
+    const isRangeStart = toks[cellIdx + 1]?.type === 'COLON';
+    const cellTokB = isRangeStart ? toks[cellIdx + 2] : undefined;
+    const validRange = !!cellTokB && cellTokB.type === 'IDENT' && looksLikeCell(cellTokB.value);
+
+    if (resolvedTableId === targetTableId) {
+      const a = parseA1(cellTokA.value);
+      if (validRange && cellTokB) {
+        const b = parseA1(cellTokB.value);
+        const va = axisValue(axis, a);
+        const vb = axisValue(axis, b);
+        const lo = Math.min(va, vb);
+        const hi = Math.max(va, vb);
+        if (delta > 0) {
+          const newLo = insertShift(lo, at);
+          const newHi = insertShift(hi, at);
+          if (newLo !== lo) {
+            repls.push({ pos: cellTokA.pos, end: cellTokA.pos + cellTokA.value.length, text: withAxisValue(axis, a, va === lo ? newLo : newHi) });
+          }
+          if (newHi !== hi) {
+            repls.push({ pos: cellTokB.pos, end: cellTokB.pos + cellTokB.value.length, text: withAxisValue(axis, b, vb === lo ? newLo : newHi) });
+          }
+        } else {
+          const newLo = deleteShiftStart(lo, at);
+          const newHi = deleteShiftEnd(hi, at);
+          if (newLo > newHi) {
+            repls.push({ pos: cellTokA.pos, end: cellTokB.pos + cellTokB.value.length, text: '#REF' });
+          } else {
+            if (newLo !== lo) {
+              repls.push({ pos: cellTokA.pos, end: cellTokA.pos + cellTokA.value.length, text: withAxisValue(axis, a, va === lo ? newLo : newHi) });
+            }
+            if (newHi !== hi) {
+              repls.push({ pos: cellTokB.pos, end: cellTokB.pos + cellTokB.value.length, text: withAxisValue(axis, b, vb === lo ? newLo : newHi) });
+            }
+          }
+        }
+      } else {
+        const v = axisValue(axis, a);
+        if (delta > 0) {
+          const nv = insertShift(v, at);
+          if (nv !== v) {
+            repls.push({ pos: cellTokA.pos, end: cellTokA.pos + cellTokA.value.length, text: withAxisValue(axis, a, nv) });
+          }
+        } else if (v === at) {
+          repls.push({ pos: cellTokA.pos, end: cellTokA.pos + cellTokA.value.length, text: '#REF' });
+        } else if (v > at) {
+          repls.push({ pos: cellTokA.pos, end: cellTokA.pos + cellTokA.value.length, text: withAxisValue(axis, a, v - 1) });
+        }
+      }
+    }
+
+    i = validRange ? cellIdx + 3 : cellIdx + 1;
+  }
+
+  wb.homeTableId = savedHome;
+  if (repls.length === 0) return raw;
+  repls.sort((x, y) => x.pos - y.pos);
+  let out = '';
+  let cursor = 0;
+  for (const r of repls) {
+    out += body.slice(cursor, r.pos) + r.text;
+    cursor = r.end;
+  }
+  out += body.slice(cursor);
+  return '=' + out;
+}
+
 function loadInitial(): DocumentState {
   try {
     const raw = localStorage.getItem(STORAGE_KEY);
@@ -1176,6 +1373,142 @@ function createStore() {
     syncWorkbook();
   }
 
+  // ---- row/col insert & delete (mid-grid, not just edge growth) ---------
+  // Unlike setTableRows/setTableCols above (pure edge resize) or
+  // removeLastRow/removeLastColumn, these shift cell data/formats/row-height
+  // (or column-width) overrides *within* the table around the insertion/
+  // deletion point, and rewrite every formula in the *whole document* that
+  // references a row/col at/after it on this table -- see
+  // `rewriteRefsForStructuralChange` above for the "how".
+
+  /** Move `doc.selection` (if it's on `tableId`) the same way a row/col
+   *  insert/delete moves cell data -- so the active cell/marquee stays on
+   *  the "same" logical cell it was on before, not wherever that grid
+   *  position now happens to be. `clampSelection` (called by every caller
+   *  right after) catches anything this pushes out of the shrunk bounds. */
+  function shiftSelectionForStructuralChange(tableId: string, axis: Axis, at: number, delta: 1 | -1) {
+    const s = doc.selection;
+    if (!s || s.tableId !== tableId) return;
+    const shift = (c: CellCoord): CellCoord => {
+      const v = axis === 'row' ? c.row : c.col;
+      const nv = delta > 0 ? insertShift(v, at) : deleteShiftStart(v, at);
+      return axis === 'row' ? { ...c, row: nv } : { ...c, col: nv };
+    };
+    doc.selection = {
+      tableId,
+      anchor: shift(s.anchor),
+      focus: shift(s.focus),
+      ranges: s.ranges?.map((r) => ({ anchor: shift(r.anchor), focus: shift(r.focus) })),
+    };
+  }
+
+  /** Rewrite every formula in the whole document referencing `targetTableId`
+   *  after its rows/cols and cell data have already been shifted to their
+   *  new shape (self-references inside `targetTableId` are included -- it's
+   *  just another table as far as this loop is concerned). */
+  function rewriteDocumentRefs(targetTableId: string, axis: Axis, at: number, delta: 1 | -1) {
+    for (const s of doc.sheets) {
+      for (const o of s.objects) {
+        if (o.kind !== 'table') continue;
+        for (const [key, raw] of Object.entries(o.cells)) {
+          const next = rewriteRefsForStructuralChange(raw, o.id, targetTableId, axis, at, delta, wb);
+          if (next !== raw) o.cells[key] = next;
+        }
+      }
+    }
+  }
+
+  /** Re-key every entry of a "col,row" map, shifting the given axis at/after
+   *  `at` by `delta` (dropping entries whose axis value === `at` when
+   *  `delta` is -1 -- that row/col's own cells are gone). Shared by
+   *  insertRow/deleteRow (axis 'row') and insertColumn/deleteColumn (axis
+   *  'col'). */
+  function shiftCellKeyedMap<T>(
+    map: Record<string, T>,
+    axis: Axis,
+    at: number,
+    delta: 1 | -1,
+  ): Record<string, T> {
+    const out: Record<string, T> = {};
+    for (const [k, v] of Object.entries(map)) {
+      const [c, r] = k.split(',').map(Number);
+      const cur = axis === 'row' ? r : c;
+      if (delta < 0 && cur === at) continue; // this row/col's own cell is gone
+      const nv = delta > 0 ? insertShift(cur, at) : deleteShiftStart(cur, at);
+      const key = axis === 'row' ? `${c},${nv}` : `${nv},${r}`;
+      out[key] = v;
+    }
+    return out;
+  }
+  /** Same idea as shiftCellKeyedMap, for a single-axis map keyed by plain
+   *  row/col number (rowHeights, colWidths). */
+  function shiftAxisKeyedMap(map: Record<number, number>, at: number, delta: 1 | -1): Record<number, number> {
+    const out: Record<number, number> = {};
+    for (const [k, v] of Object.entries(map)) {
+      const cur = Number(k);
+      if (delta < 0 && cur === at) continue;
+      out[delta > 0 ? insertShift(cur, at) : deleteShiftStart(cur, at)] = v;
+    }
+    return out;
+  }
+
+  function insertRow(tableId: string, at: number) {
+    const t = tableById(tableId);
+    if (!t) return;
+    const clamped = Math.max(0, Math.min(Math.floor(at), t.rows));
+    t.cells = shiftCellKeyedMap(t.cells, 'row', clamped, 1);
+    if (t.formats) t.formats = shiftCellKeyedMap(t.formats, 'row', clamped, 1);
+    if (t.rowHeights) t.rowHeights = shiftAxisKeyedMap(t.rowHeights, clamped, 1);
+    t.rows += 1;
+    shiftSelectionForStructuralChange(tableId, 'row', clamped, 1);
+    rewriteDocumentRefs(tableId, 'row', clamped, 1);
+    clampSelection(tableId);
+    syncWorkbook();
+  }
+  function deleteRow(tableId: string, at: number) {
+    const t = tableById(tableId);
+    if (!t || t.rows <= 1) return;
+    const clamped = Math.max(0, Math.min(Math.floor(at), t.rows - 1));
+    t.cells = shiftCellKeyedMap(t.cells, 'row', clamped, -1);
+    if (t.formats) t.formats = shiftCellKeyedMap(t.formats, 'row', clamped, -1);
+    if (t.rowHeights) t.rowHeights = shiftAxisKeyedMap(t.rowHeights, clamped, -1);
+    t.rows -= 1;
+    shiftSelectionForStructuralChange(tableId, 'row', clamped, -1);
+    rewriteDocumentRefs(tableId, 'row', clamped, -1);
+    pruneEmptyMaps(t);
+    clampTableView(t);
+    clampSelection(tableId);
+    syncWorkbook();
+  }
+  function insertColumn(tableId: string, at: number) {
+    const t = tableById(tableId);
+    if (!t) return;
+    const clamped = Math.max(0, Math.min(Math.floor(at), t.cols));
+    t.cells = shiftCellKeyedMap(t.cells, 'col', clamped, 1);
+    if (t.formats) t.formats = shiftCellKeyedMap(t.formats, 'col', clamped, 1);
+    t.colWidths = shiftAxisKeyedMap(t.colWidths, clamped, 1);
+    t.cols += 1;
+    shiftSelectionForStructuralChange(tableId, 'col', clamped, 1);
+    rewriteDocumentRefs(tableId, 'col', clamped, 1);
+    clampSelection(tableId);
+    syncWorkbook();
+  }
+  function deleteColumn(tableId: string, at: number) {
+    const t = tableById(tableId);
+    if (!t || t.cols <= 1) return;
+    const clamped = Math.max(0, Math.min(Math.floor(at), t.cols - 1));
+    t.cells = shiftCellKeyedMap(t.cells, 'col', clamped, -1);
+    if (t.formats) t.formats = shiftCellKeyedMap(t.formats, 'col', clamped, -1);
+    t.colWidths = shiftAxisKeyedMap(t.colWidths, clamped, -1);
+    t.cols -= 1;
+    shiftSelectionForStructuralChange(tableId, 'col', clamped, -1);
+    rewriteDocumentRefs(tableId, 'col', clamped, -1);
+    pruneEmptyMaps(t);
+    clampTableView(t);
+    clampSelection(tableId);
+    syncWorkbook();
+  }
+
   // ---- cell formatting (alignment, number format, colours, bold/italic) ---
   const fmtKey = (c: number, r: number) => `${c},${r}`;
   function cellFormat(tableId: string, col: number, row: number): CellFormat {
@@ -1837,6 +2170,10 @@ function createStore() {
     rowHeightOf,
     setTableRows,
     setTableCols,
+    insertRow,
+    deleteRow,
+    insertColumn,
+    deleteColumn,
     setTableView,
     // cell formatting
     cellFormat,