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Using traits to reuse code in Pharo
While working on a small Tetris-like clone in Pharo, I found an opportunity to reuse some code.It's common for Tetris implementations to show a small preview of the tetrimino that comes next. Here's...
View ArticleA couple of quick notes on Mercury #1
I'm trying to learn about Mercury programming language. Here's a quick list of things I learned recently about it.Getting a Windows version of the Mercury compilerI was able to get a version of the...
View ArticleDeterminism categories in Mercury
When you define a predicate in Mercury, you have to specify if it can fail or succeed more than once. This is called a determinism category.The category is specified as part of a predicate (or...
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Some things I learned while creating a small program in Mercury
Some time ago I started creating a program using the Mercury programming language to create images using the Escape Time algorithm. The goal was to learn about the language by solving a small...
View ArticleSolving a small primary school problem with Prolog
A couple of days ago my small son came home with math homework from school. The problem: add parenthesis to the following arithmetic expression so it makes sense.14*3-8/2=17When I saw that, I thought...
View ArticleA simple language with indentation based blocks (part 0)
One of the first things I noticed when reading about Python, is the use of indentation for defining code blocks. For example:def foo(x): while x <20: if x >10: print"argument is greater than...
View ArticleA simple language with indentation based blocks. Part 1: Parsing combinators
In this post, I'm going to start with the implementation of the parser using the F# programming language. There are several tools for creating parsers for example...
View ArticleA simple language with indentation based blocks. Part 2: Expressions
The focus of the second part will be expression parsing. The desired grammar for the expression small language experiment is the following (here in pseudo BNF):NESTED_EXPRESSION ='(' EXPRESSION ')'...
View ArticleA simple language with indentation based blocks. Part 3: Blocks
In this post we're going to add support for statements containing blocks which is the main goal of these series of posts.Identifying blocks by using indentationThe technique we're going to use to...
View ArticleA simple language with indentation based blocks. Part 4: Improving error...
Going back to our first post, we defined the type of a parser function as :ReaderState -> (('a * ReaderState) option )Which means that a parser is a function from a reader state to an...
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A small Tetris-like clone using J and ncurses. Part 1
For me, the J programming language it's a very intriguing. It is full of ideas and concepts that I'm not familiar with. Getting to know a programming language it's not only about learning the syntax....
View ArticleA small Tetris-like clone using J and ncurses. Part 2
This is part two of our Tetris-like clone in J series. In this part we're going to see how the ncurses interface was created.Creating the ncurses UITo create the user interface we used the ncurses UI...
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Using Racklog for parsing
This post shows a small experiment of creating parsing predicates using the Racket's Racklog package . This package enables the use of logic programming features inside Racket. Logic programming...
View ArticleA quick note about programming in Prolog
Prolog predicates work in different ways depending on how you use them. A simple example is the append predicate. One may say that append is used to get the result of appending two lists. For...
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First programming language: GW-BASIC
Like many developers my age, the first programming language I ever used was BASIC. Specifically, GW-BASIC in a nice Epson "Abacus" XT machine with a green-on-black monitor back in primary school.For...
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A small experiment with fragment shaders
I wanted to work on an experiment that allowed me to learn a little bit about modern graphics programming with OpenGL (with shaders that is). A nice choice is the 'hello world; of graphics...
View ArticleReading APL #1: Roman numerals to decimal
As part of a new recurring series I’m going to take a small APL function or program and try to break it down in to its parts. I hope this is going to help me get a better understanding of the...
View ArticleA small programming exercise in APL #1
This post shows a possible solution written in APL for the following programming problem: Given an array, determine if a value 'number' is found in every consecutive segment of 'size' elements. For...
View ArticleA small programming exercise in APL #2: Combinations
In this post I'm going to continue my APL exploration by working in a possible solution for the problem of generating all the combinations of 'n' elements of an array.Generating the 'n' combinations of...
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Exploring a Webpack stats file with Prolog
A couple of days ago I was reading about the Webpack statistics file created using the following command line options:npx webpack --profile --jsonThis file contains a lot of information collected by...
View ArticleExecuting code from a buffer with Rust on Windows
Creating and executing code at runtime is an intriguing topic. It is one of the pieces that makes it possible to write JIT compilers for things like Java or C#.Creating a byte array with executable...
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Implementing WHILE in a toy BASIC interpreter
While working on a toy BASIC implementation, I ran into an unexpected challenge implementing the WHILE instruction. The implementation of this instruction seems simple. Here is an example : 10 X = 1...
View ArticleSome considerations for using closures in Rust/WASM
Here are a couple of things I learned while trying to pass a Rust closure to a JavaScript function. Some of these notes are a result of my lack of experience with Rust and Rust/WASM.Passing a closure...
View ArticleHaskell 'newtype' and the record syntax
While reading some Haskell code snippets I found something that seemed confusing. The snippet involved newtype and record syntax. A simplified example is the following:newtype PersonName = PersonName {...
View ArticleA quick look at functors in OCaml
A couple of weeks ago I was working on a small program that required generating code in different ways depending on a user option. I was trying to make as few changes as possible. Because of the way...
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