Cactus

About myself

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I'm Dr. Gergő Érdi (Érdi Gergő in the original Hungarian order of surname first), born in Budapest and living in Singapore since 2011.

I graduated from Semmelweis University of Medicine with an MD in 2005. Meanwhile, in 2003 I also started studying at the Computer Science faculty of Eötvös Loránd University, and got my CS master's degree in 2011.

Between 2005 and 2011, I've worked at Intentional Software. Since 2011, I'm currently at Standard Chartered Bank.

Retrocomputing with Clash: Haskell for FPGA Hardware Design

My new book on everything Clash, Haskell, and old computers, is out now! Check out the sample chapters and buy it from Leanpub (e-book) or Lulu (hardcopy).

Formatting serial streams in hardware

12 August 2024 (programming haskell clash fpga)

I've been playing around with building a Sudoku solver circuit on an FPGA: you connect to it via a serial port, send it a Sudoku grid with some unknown cells, and after solving it, you get back the solved (fully filled-in) grid. I wanted the output to be nicely human-readable, for example for a 3,3-Sudoku (i.e. the usual Sudoku size where the grid is made up of a 3 ⨯ 3 matrix of 3 ⨯ 3 boxes): 

4 2 1  9 5 8  6 3 7  
8 7 3  6 2 1  9 5 4  
5 9 6  4 7 3  2 1 8  

3 1 2  8 4 6  7 9 5  
7 6 8  5 1 9  3 4 2  
9 4 5  7 3 2  8 6 1  

2 8 9  1 6 4  5 7 3  
1 3 7  2 9 5  4 8 6  
6 5 4  3 8 7  1 2 9

This post is about how I structured the stream transformer that produces all the right spaces and newlines, yielding a clash-protocols based circuit.

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Older entries

My software

These days, I'm mostly just writing small programs for fun, or throw-away code relevant to some theoretical subjects I happen to get interested in in the field of functional programming, and then push them to my GitHub repos or write about them in my blog. Ones you might find interesting include:

Full list (including older stuff)

Talks

These are slides and recordings from some talks I've done over the years at various meetup groups and conferences.

Papers

Pattern synonyms

Symbolic execution

Syntax-generic programming

Compositional type checking