Add Excel processing functionality with merge pattern application

- Introduced `index.ts` to read an Excel file and apply merge patterns to specified ranges.
- Created `lib.ts` with utility functions for column number conversion and merge pattern application.
- Updated execution counts in `carbone.ipynb` to reflect the new code structure.

notebooks/excel/index.ts

@@ -0,0 +1,43 @@
+import ExcelJS from "exceljs";
+import { applyMergePattern } from "./lib";
+
+/* const inputFile = Bun.file("mapa.xlsx");
+const inputBuffer = await inputFile.arrayBuffer();
+
+const workbook = new ExcelJS.Workbook();
+await workbook.xlsx.load(inputBuffer); */
+
+const workbook = new ExcelJS.Workbook();
+await workbook.xlsx.readFile("mapa.xlsx");
+
+const sheetName = 'RÍGIDO-Anexo 2 (A)'
+const sheet = workbook.getWorksheet(sheetName)
+if (!sheet) {
+    throw new Error(`Workbook has no sheet named: ${sheetName}`);
+}
+
+const CICLOS = 9;
+const matrizAsignaturas = {
+    startColumns: ["C", "I", "O", "U", "AA"],
+    firstStartRow: 8,
+    mergeWidthInColumns: 5,
+    mergeHeightInRows: 3,
+    mergeBlockCount: CICLOS,
+    rowStepBetweenBlocks: 14 - 8,
+} as const;
+const semestres = {
+    startColumns: ["A"],
+    firstStartRow: 7,
+    mergeWidthInColumns: 1,
+    mergeHeightInRows: 5,
+    mergeBlockCount: CICLOS,
+    rowStepBetweenBlocks: 13 - 7,
+} as const;
+
+applyMergePattern(sheet, matrizAsignaturas);
+applyMergePattern(sheet, semestres);
+
+const outputBuffer = await workbook.xlsx.writeBuffer();
+await Bun.write("excel2.xlsx", outputBuffer);
+
+const end = Bun.nanoseconds();

notebooks/excel/lib.ts

@@ -0,0 +1,57 @@
+import { type Worksheet } from "exceljs";
+
+
+/**
+ * Converts an Excel column label to a 1-based number.
+ * Example: A -> 1, Z -> 26, AA -> 27
+ */
+function columnToNumber(label: string): number {
+  let n = 0;
+
+  for (let i = 0; i < label.length; i++) {
+    n = n * 26 + label.charCodeAt(i) - 64;
+  }
+
+  return n;
+}
+
+/**
+ * Generates merge ranges like:
+ * C8:G10, I8:M10, ...
+ * then C14:G16, I14:M16, ...
+ */
+type MergeRangePattern = {
+  startColumns: readonly string[];
+  firstStartRow: number;
+  mergeWidthInColumns: number;
+  mergeHeightInRows: number;
+  mergeBlockCount: number;
+  rowStepBetweenBlocks: number;
+};
+
+export function applyMergePattern(sheet: Worksheet, config: MergeRangePattern) {
+
+  const {
+    startColumns,
+    firstStartRow,
+    mergeWidthInColumns,
+    mergeHeightInRows,
+    mergeBlockCount,
+    rowStepBetweenBlocks
+  } = config;
+
+  for (let block = 0; block < mergeBlockCount; block++) {
+
+    const rowStart = firstStartRow + block * rowStepBetweenBlocks;
+    const rowEnd = rowStart + mergeHeightInRows - 1;
+
+    for (const column of startColumns) {
+
+      const colStart = columnToNumber(column);
+      const colEnd = colStart + mergeWidthInColumns - 1;
+
+      sheet.mergeCells(rowStart, colStart, rowEnd, colEnd);
+
+    }
+  }
+}