Evil Spreadsheet

evil-spreadsheet.js

// Inspired by this Python code: https://ralsina.me/weblog/posts/BB585.html
// Really really limited, but it works. "Look ma, no DAG!"

function evil(formula, sheet) {
  with (sheet.functions) {
    with (sheet.cells) {
      return eval(formula);
    }
  }
}

class EvilSpreadsheet {
	cells;
	functions;
	constructor(functions = {}, cells = {}) {
    this.cells = cells;
		this.functions = functions;
		return new Proxy(this, {
      get(sheet, cell) {
        return evil(sheet.cells[String(cell).toUpperCase()], sheet);
      },
      set(sheet, cell, formula) {
        sheet.cells[String(cell).toUpperCase()] = formula;
        return true;
      }
    });
	}
}

const sheet = new EvilSpreadsheet(Math);
sheet['a1'] = 6;
sheet['a2'] = 7;
sheet['a3'] = 'log(A1 * A2)';

sheet['a3']; // 3.7376696182833684