There are many interesting things happening in a spreadsheet. It needs an interactive user interface where users can edit data and formulas in cells, it needs to parse formulas that users write, it needs to evaluate formulas and show results on the fly and it also needs to handle errors such as division by zero and circular references. In this live coding session, Tomas will attempt to implement all of these features live on stage!
The talk will show a number of techniques and principles that are useful even if you do not plan to create a competition to Excel 365 and Google Sheets!

Along the way, you will learn about the Fable compiler which makes it easy to compile correct, functional-first code to JavaScript and run it in a browser. You will also learn about a number of powerful functional programming techniques. We will use the Elm architecture to create an interactive web application in a functional way and we will use parser combinators to easily create parser for formulas. Finally, we will look at the…

What do you do when you want to build a pretty data visualization, but none of the existing libraries does quite the thing that you want? Why, of course! You create your own data visualization library from scratch!

It takes about a week until you realize that getting all the details right in data visualization is a nightmare and this was never a good idea. However, it also turns out that functional approach is a great fit for data visualization and you can build amazing visualizations with just a few lines of elegant composable code.

In this talk, I will describe the design of a data visualization library in The Gamma. However, I will try to talk not only about categorical and continuous data, projections and misleading charts. I will extract more general principles of functional library design that you can use when tackling problems in a wide range of other domains.

For those who want spoilers, you can find some sample charts created using the library we're going to discuss here: http://turing.thegamma.…

Composable data visualization library for JavaScript - compostjs/compost

What do you do when you want to build a pretty data visualization, but none of the existing libraries does quite the thing that you want? Why, of course! You create your own data visualization library from scratch!

It takes about a week until you realize that getting all the details right in data visualization is a nightmare and this was never a good idea. However, it also turns out that functional approach is a great fit for data visualization and you can build amazing visualizations with just a few lines of elegant composable code.

In this talk, I will describe the design of a data visualization library in The Gamma. However, I will try to talk not only about categorical and continuous data, projections and misleading charts. I will extract more general principles of functional library design that you can use when tackling problems in a wide range of other domains.

For those who want spoilers, you can find some sample charts created using the library we're going to discuss here: http://turing.thegamma.…

Composable data visualization library for JavaScript - compostjs/compost