The task is to make an Excel-like table with support for the simplest formulas. Recalculation of values in the cells should occur immediately upon loss of focus and affect only those cells whose values should be changed. Do not recalculate the whole table every time (if not necessary). Use pure JS (ES6), HTML, CSS. Use third-party frameworks, libraries is not encouraged for this task. Task result will be viewed with the latest version of chrome (desktop and mobile).
Let the table size be 100x1000 (WxH)
A cell can contain numbers and formulas. Numbers can be either integer or decimal floating point (e.g. 15, 324, -3, 0.08, -123.0001).
Formulas begin with a = sign and an expression.
An expression consists of operands and operators. Operators are one of 4 arithmetic operations, operands - numbers and addresses of cells.
=2+2
=A12
=AB33*3
<cell> :: = <empty> | <number> | <formula>
<empty> :: = ""
<number> :: = <integer> | float>
<integer> :: = "-" [0-9] + | [0-9] +
<float> ::= "-" [0-9] + "." [0-9] + | [0-9] + "." [0-9] +
<formula> :: = "=" <expression>
<expression> :: = <number> | <cell address> | <expression> <operator> <expression>
<cell address>: = <column> <row>
<column> :: = [A-Z] +
<row> :: = [0-9] +
<operator>: == "-" | "+" | "/" | "*"
Good luck