https://github.com/sjhorn/visicalc_engine
A clone of the visicalc spreadsheet engine in dart
https://github.com/sjhorn/visicalc_engine
a1-notation petitparser spreadsheet visicalc worksheet
Last synced: 7 months ago
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A clone of the visicalc spreadsheet engine in dart
- Host: GitHub
- URL: https://github.com/sjhorn/visicalc_engine
- Owner: sjhorn
- License: bsd-3-clause
- Created: 2024-03-30T09:26:49.000Z (about 2 years ago)
- Default Branch: main
- Last Pushed: 2024-04-16T13:07:54.000Z (about 2 years ago)
- Last Synced: 2025-10-23T05:02:10.035Z (7 months ago)
- Topics: a1-notation, petitparser, spreadsheet, visicalc, worksheet
- Language: Dart
- Homepage:
- Size: 325 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
- Authors: AUTHORS
Awesome Lists containing this project
README
# VisiCalc Engine Package
[](https://pub.dev/packages/visicalc_engine)
[](https://github.com/sjhorn/visicalc_engine/actions)
[](https://codecov.io/gh/sjhorn/visicalc_engine)
[](https://github.com/sjhorn/visicalc_engine/issues)
[](https://github.com/sjhorn/visicalc_engine/network)
[](https://github.com/sjhorn/visicalc_engine/stargazers)
This package implements a clone of the VisiCalc spreadsheet engine in a dart library that works by parsing the strings of cells (Map) and calculating the result considering references to other cells.
The screenshot below shows the original user interface of Visicalc made by [Dan Bricklin and Bob Frankston](https://danbricklin.com/visicalc.htm).
From [wikipedia](https://en.wikipedia.org/wiki/VisiCalc)
> VisiCalc ("visible calculator") is the first spreadsheet computer program for personal computers, originally released for Apple II by VisiCorp on October 17, 1979.It is considered the killer application for the Apple II, turning the microcomputer from a hobby for computer enthusiasts into a serious business tool, and then prompting IBM to introduce the IBM PC two years later.More than 700,000 copies were sold in six years, and up to 1 million copies over its history
## Features
- Supports the calculation and reference language from VisiCalc explained in the [reference card](https://www.bricklin.com/history/refcard1.htm)
## Getting started
Simple usage examples below:
```dart
import 'package:a1/a1.dart';
import 'package:visicalc_engine/visicalc_engine.dart';
void main(List arguments) {
final sheet = {
'A1'.a1: '/FR-12.2',
'A2'.a1: '(a5+45)',
'A3'.a1: '/F*13',
'A4'.a1: '+A2+A5-A6',
'A5'.a1: '-A3/2+2',
'A6'.a1: '/F\$.23*2',
'B1'.a1: '+A1+A3*3',
'B2'.a1: '(A1+A3)*3',
'B3'.a1: '12.23e-12',
'B4'.a1: '.23e12',
'B5'.a1: '/FRb4',
'B6'.a1: '+b2',
'B7'.a1: '@sum(a1...b6)',
'D13'.a1: '+b2',
};
final worksheet = Engine.fromMap(sheet, parseErrorThrows: true);
print(worksheet);
// Change cell
var b5 = worksheet["B5".a1];
print('B5 formula was ${b5?.formulaType?.asFormula} = $b5');
print('Now setting B5 to formula a1');
worksheet['B5'.a1] = '+a1';
b5 = worksheet["B5".a1];
print('Now B5 formula is ${b5?.formulaType?.asFormula} = $b5');
print(worksheet);
print('Output to a .vc file\n: ${worksheet.toFileContents()}');
// .vc file example
final fileContents = '''\
>A1:/FL"TRUE\r
>A2:+B5*10\r
>A3:+B3+1\r
>A4:"tes\r
>A5:@SUM(B2...B5)\r
>B1:/FR"label\r
>B2:123\r
>B3:@PI\r
>B4:+B3\r
>B5:.23*2\r
\u0000''';
print('Parsing an example of a VisiCalc .vc file format');
final engine = Engine.fromFileContents(fileContents);
print(engine);
}
```
The result looks as follows:
```
A fx | A | B fx | B | C fx | C | D fx | D |
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1 -12.2 | -12.2 | +A1+A3*3 | 26.8 | | | | |
2 (A5+45) | 40.5 | (A1+A3)*3 | 2.4 | | | | |
3 13 | ******** | 1.223e-11 | 1.223e-11 | | | | |
4 +A2+A5-A6 | 35.54 | 230000000000 | 230000000000 | | | | |
5 -A3/2+2 | -4.5 | B4 | 230000000000 | | | | |
6 0.23*2 | 0.46 | +B2 | 2.4 | | | | |
7 | | @SUM(A1...B6) | 460000000104.4000244 | | | | |
8 | | | | | | | |
9 | | | | | | | |
10 | | | | | | | |
11 | | | | | | | |
12 | | | | | | | |
13 | | | | | | +B2 | 2.4 |
B5 formula was B4 = 230000000000
Now setting B5 to formula a1
Now B5 formula is +A1 = -12.2
A fx | A | B fx | B | C fx | C | D fx | D |
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1 -12.2 | -12.2 | +A1+A3*3 | 26.8 | | | | |
2 (A5+45) | 40.5 | (A1+A3)*3 | 2.4 | | | | |
3 13 | ******** | 1.223e-11 | 1.223e-11 | | | | |
4 +A2+A5-A6 | 35.54 | 230000000000 | 230000000000 | | | | |
5 -A3/2+2 | -4.5 | +A1 | -12.2 | | | | |
6 0.23*2 | 0.46 | +B2 | 2.4 | | | | |
7 | | @SUM(A1...B6) | 230000000092.1999816 | | | | |
8 | | | | | | | |
9 | | | | | | | |
10 | | | | | | | |
11 | | | | | | | |
12 | | | | | | | |
13 | | | | | | +B2 | 2.4 |
Output to a .vc file
: >D13:+B2
>B7:@SUM(A1...B6)
>B6:+B2
>A6:/F$0.23*2
>B5:+A1
>A5:-A3/2+2
>B4:230000000000
>A4:+A2+A5-A6
>B3:1.223e-11
>A3:/F*13
>B2:(A1+A3)*3
>A2:(A5+45)
>B1:+A1+A3*3
>A1:/FR-12.2
Parsing an example of a VisiCalc .vc file format
A fx | A | B fx | B |
-----------------------------------------------------------------------------------------------
1 "TRUE | TRUE | "label | label |
2 +B5*10 | 4.6 | 123 | 123 |
3 +B3+1 | 4.1415926536 | @PI | 3.1415926536 |
4 "tes | tes | +B3 | 3.1415926536 |
5 @SUM(B2...B5) | 129.7431853072 | 0.23*2 | 0.46 |
```
The `test/` directory explores other use cases for the visicalc_engine types and library.
## Usage
The code above in getting started is also available in the `example/example.dart`
## Reference
* The [Visicalc user interface and logo](https://en.wikipedia.org/wiki/VisiCalc) are referenced from wikipeida.
* The parsing depends on the great library [petitparser](https://pub.dev/packages/petitparser) by Lukas Renggli.
* For A1 Notation we leverage the a1 library [a1](https://pub.dev/packages/a1).