I've had some ideas for a game simmering for a while now and I've finally committed to learning Godot to see what I can put together. I'm still in need of some inspiration, though, and I know there's a few folks around here who have made games. Complete, polished, sketchy, half-baked - doesn't matter! - I'd love to see what people here have come up with!

Hi folks--

To those more knowledgeable than I am:

What would be the best local solution to extract numerical data from a batch of PDF file reports? The values I want are interspersed among word processor formatted tables and irrelevant text. The text and table formatting are (nearly) identical across reports. The data I want vary across reports. The PDFs are not of images...I can select and copy text without OCR. I have thousands to process, and the data themselves are confidential (I have clearance) and cannot be shared. I can use Windows or Linux but no MacOS.

I am technically inclined, so I bashed my head against regular expressions just enough to use notepad++ to find and delete most of the irrelevant stuff and make a CSV, but it's a hacky, imprecise method and not nearly automated enough for batches. For reference, I don't code for a living or even as a hobby, but I use R and bash, am familiar with IDEs, and can follow pseudocode well enough to edit and use scripts.

Any thoughts? Thanks in advance!

Apologies if this isn't an appropriate place to post this.

Inspired by a paper I found a while back (https://publications.lib.chalmers.se/records/fulltext/215545/local_215545.pdf), I tried my hand at implementing a program (in C#) to create ASCII art from an image. It works pretty well, but like they observed in the paper, it's pretty slow to compare every tile to 90-some glyphs. In the paper, they make a decision tree to replicate this process at a faster speed.

Recently, I revisited this. I thought I'd try making a neural net, since I found the idea interesting. I've watched some videos on neural nets, and refreshed myself on my linear algebra, and I think I've gotten pretty close. That said, I feel like there's something I'm missing (especially given the fact that the loss isn't really decreasing). I think my problem is specifically during backpropagation.

Here is a link to the TrainAsync method in GitHub: https://github.com/bendstein/ImageToASCII/blob/1c2e2260f5d4cfb45443fac8737566141f5eff6e/LibI2A/Converter/NNConverter.cs#L164C59-L164C69. The forward and backward propagation methods are below it.

If anyone can give me any feedback or advice on what I might be missing, I'd really appreciate it.

I have a relative whose 8 year old has shown a keen interest in coding. He even takes books out of the library about coding even though he's never done it and I dont think he understands most of what he's reading. Seems like a little Bill Gates just dying to get started.

I used to teach LOGO to kids back when the dinosaurs roamed the earth and I looked at some recent versions. Its good, and the logic is all there, but the end results are fairly mundane for a kid who's already experienced amazing video games. Then I stumbled across Scratch, a much more visual programming tool and it seems to fit what we need. Scratch allows kids to make animations, simple games, even do motion detection, music all with sprites that they can manipulate using drag and drop coding blocks. Lots of online video tutorials that he can follow himself too. https://scratch.mit.edu/

Before I dive headlong into Scratch, just wondering if there are other even better tools for teaching coding to kids? Or what your experience might be with them?

Hi,

I'm curious if anyone in this group has achieved success in game development, whether that's carving out a career or earning any amount of income from it.

I'm currently working as a software developer, but my passion lies in game development. I'm all too aware that achieving any measure of success in this field is next to impossible. Hence, I'm reaching out here, hoping to gather insights and advice from those who have walked this path in the past, or those who are currently walking alongside/behind me.

One of my specific questions is about the types of games I should focus on creating. Specifically, I've heard differing opinions on whether it's more advantageous to develop a series of small games with advertisements for mobile platforms or to invest in larger, premium games for platforms like Steam. Can anyone share their insights or experiences regarding this dilemma? Is there a clear advantage to one approach over the other?

Currently I am using godot to make a larger scale game, but I am considering switching to defold and making smaller scale games with ads.

I saw some folks here discuss making games for the playdate. How much should one consider targeting niche platforms like this? Some of the users I saw discuss this seem to have had good success.

Some general questions: How did you break into game dev? What were you doing before? Do you see game dev as a viable career, only as a source of side income, or is it just a hobby?

Any guidance or experiences you can share would be greatly appreciated.

I went to university for computer science up until the pandemic started. It was great. I remember working on so many projects that were basic but a lot of fun and others that were a lot more complex but still fun and rewarding. For example, one of the staples of beginner projects is Conway's Game of Life. I remember building that in HTML, CSS, and Java Script. One of my other favorite projects was a website for alum to visit to see alumni news and events, and also to lookup other alum.

What were your favorite projects when learning to code?

Just for a moment, forget all of the technical pros and cons, the static typing, just-in-time compilation, operator overloading, object orientation to the max...

Is there a programming language that you've just found to be... fun?

Is there one that you'd pick above all else for personal or company projects, if you had your druthers, because you would simply be so excited to use it?

And then, is there something missing in that "fun" language that's preventing it from actually becoming a reality (i.e. small community, lack of libraries, maintenance ended in the 80s, etc.)?

I am asking as I have just created one. I won't advertise it here, as it feels not in good faith and I don't think Tildes is the right audience (I imagine most of the techies here are probably fairly seasoned).

I want to offer some kind of programming tuition to people at a good rate (read: affordable to those that might be on a low income but wish to learn). I am doing this to raise money for my local cardiology ward, who have just been told there isn't enough in the budget to cover their Christmas party this year. Morale is low there, and I'd like to help cover the deficit.

How would you structure something like this?

Initially, I have written that I have no set fee and am happy to offer services on case-by-case basis (words to that effect). But in a discussion with a friend, they suggested I should do something like:

• Small donation (£1 - £25): Access to a chatroom (Discord?) where someone can ask questions, and I'll strive to answer and help them as fast as possible)
• Medium donation (£25 - £50): I will arrange a group session where I cover some basic programming concepts and host a Q&A at the end to help bridge any gaps in understanding.
• Large donation (£50+): I will arrange a one-to-one session (via call, video or instant messaging) where I will help go more in-depth on a topic or help debug a specific problem.

If anyone has any experience with this type of thing, I'd appreciate any advice. I have only been a professional software developer for three years, so I am reasonably experienced, but not exactly an industry veteran. I want to set realistic expectations for this service.

I'm happy to share a link to the open collective via private message if anyone wants to have a look over it and offer any advice.

Hi everyone — I am trying to get a job in web development after a decade in a mostly unrelated field.

I am looking for ideas and tips to create a portfolio to send with applications. All of the websites I worked on ages ago have been taken offline or redesigned by someone else. I do have a website I created for my music, but it’s just vanilla HTML. I also have a personal website which is really the only thing I have to show.

I know HTML/CSS quite well, but that’s basically it. I’ve worked with WordPress for years but only just recently began learning enough PHP to do anything custom. I don’t really know Javascript much at all.

I have quite a few paid courses through Udemy for all these different areas but even as I have completed them, I don’t feel confident in knowledge of the different languages. These courses nearly always come with projects that the students create with the instructor. Should I use these as part of my portfolio? For some reason I never felt right doing that, since I didn’t build it myself.

So I guess I’m curious (if any of you are web developers) if you have suggestions for how to fill out a portfolio without any previous work examples.

Side note: I wasn’t sure how to word the title or my question particularly well so please edit it more clearly, Those Who Can Edit.

edit: thank you to everyone who took the time to reply to this. it’s all been very helpful and i appreciate everyone’s input immensely!

Background: Bitwise operators are operators that perform conditional operations at the binary level. These operators are bitwise AND &, bitwise OR |, bitwise XOR ^, and bitwise NOT ~, not to be confused with their logical operator counterparts, i.e. &&, ||, !=, and ! respectively.

Specifically, these operations take the binary values of the left- and right-hand terms and perform the conditional operation on each matching bit position between both values.

For instance, 3 | 4 takes the binary value 010 from 2 and 100 from 4. From left to right, we compare 0 || 1, 1 || 0, and 0 || 0 to get 110 as the resulting binary. This produces the integer value 6.

Goal: Your challenge is to implement one or more of these bitwise operators without using the native operators provided to you by your language of choice. Logical operators are allowed, however. These operators should work on integer values. These operators will likely take on the form of a function or method that accepts two arguments.

Bonus challenges:

• Implement all of the operators.
• Don't use any native binary conversion utilities.
• Whether or not you implement all operators, write your code in such a way that allows for good code reusability.
• For statically typed languages, handle integers of different types (e.g. int vs. uint).

Edit: Minor correction for the sake of accuracy, courtesy of @teaearlgraycold.

I've been using mostly C at my current job for about half a year now, and I find myself reusing some little function that I've written for another code base in current projects. I'm relatively new to this, so I'm wondering if it makes sense to have a repertoire of general purpose utility functions and whatnot for future use.

I mean, the language's pretty established and whatever I think of must have been written by somebody else already, so is there even a need for what I'm talking about? Are there well-known open source libraries that resemble what I am talking about? Should I just include them instead of writing my own?

Sorry if this is a bit vague. General purpose as in string manipulation, debug output, buffer operations, implementations of data types not in C, etc., just to name a few examples.

Code is usually version controlled nowadays in git or some other VCS. These typically operate on text files and record the changes applied to the files over their history. One drawback from this is that formatting of the code can introduce changesbto the files that make no semantic difference, e.g. newlines are added/removed, indentation is altered etc.

Consistent formatting makes the code easier to read, but the style used is an aesthetic preference. There might be objective reasons for readability in at least the extreme cases, but in many cases the formatting is purely a preferred style.

If we instead version controlled code in the form of an abstract syntax tree (AST) (possibly even as just a series of transformations on that tree), we could have any formatting we'd like! When editing the code we would just be changing a projection of the AST and when we've made our changes the transformations could be made to the stored AST. If two languages shared the same AST the choice of language even becomes a choice for the programmer. Sadly this has some limitations since ASTs are usually language specific... But we could possibly take this a step further.

Could we take a compiled binary and use that as the basis for generating an AST? This is essentially what decompilers do. For heavily optimized code this is severely limited, but for debug builds a lot of extra information is retained in the binary that can be utilized to construct a sensible representation. This way of storing code the language used becomes a style preference! Code compiled from one language might become alien when viewed in another language (thinking of lazy Haskell code viewed in C), but maybe that is a corner case?

There are issues when considering binaries for different platforms. A binary for the JVM isn't the same as one for ARM64 or one compiled to run on an x86. So there are some limitations there...

One (very) good thing about storing code as text files is the ubiquity of software capable of viewing and editing text. It would however be cool if we could make programming language a stylistic preference that is compatible with other languages! At least the AST part should be perfectly achievable.

Hi Everyone!

I'm looking to donate some money to a charity that is focused on helping children learn how to code.
I've always heard that lots of charities are scams, and I was hoping to get the opinions of you fine folks about a good charity to donate to!

Hi everyone! It's been a long time since last programming challenge ^list, and here's a nice one I've encountered.

If you search for something like 7km to AU, you'll get your answer. But how is it done? I don't think they hardcoded all 23 units of distance and every conversion factor between them.

If you were programming a conversion system - how would you do it?

First of all, you have input in format that you can specify, for example something like this:

meter kilometer 1000
mile kilometer 1.609344
second minute 60
...

Then you should be able answer queries. For example 7 mile meter should convert 7 miles to meters, which is 11265.41.

Can you design an algorithm that will convert any unit into any other unit?

Edit: Some conversion rates I extracted from wikipedia:

ångström
0.1nm
astronomical unit
149597870700m
attometre
0.000000000000000001m
barleycorn
8.4m
bohr
0.00846
cable length (imperial)
185.3184m
cable length
185.2m
cable length (US)
219.456m
chain (Gunters)
20.11684m
cubit
0.5m
ell
1.143m
fathom
1.8288m
femtometre
0.00000000000001m
fermi
0.00000000000001m
finger
0.022225m
finger (cloth)
0.1143m
foot (Benoit)
0.304799735m
foot (Cape) (H)
0.314858m
foot (Clarke's) (H)
0.3047972654m
foot (Indian) (H)
0.304799514m
foot,metric
0.31622776602m
foot,metric (long)
0.3m
foot,metric (short)
0.30m
foot (International)
0.3048m
foot (Sear's) (H)
0.30479947m
foot (US Survey)
0.304800610
french
0.0003m
furlong
201.168m
hand
0.1016m
inch
0.0254m
league
4828m
light-day
25902068371200m
light-hour
107925284880m
light-minute
17987547480
light-second
299792458m
light-year
31557600light-second
line
0.002116m
link (Gunter's)
0.2011684m
link (Ramsden's; Engineer's)
0.3048m
metre
1m
m
1metre
km
1000m
mickey
0.000127
micrometre
0.000001
mil; thou
0.0000254
mil
10km
mile (geographical)
6082foot (International)
quarter
0.2286m
rod
5.0292m
rope
6.096m
shaku
0.303 0303m
span (H)
0.2286m
stick (H)
0.0508m
toise
1.949 0363m
twip
1.76310
yard
0.9144m

For those who haven't seen my essay-length posts in the past, I occasionally like to delve into explaining different programming concepts, particularly with regards to making your code easier to manage. Sometimes this has to do with how you structure you code and projects, and at others it has to do with how you think about the problems you're solving. I've been in the mood to write up on yet another programming subject, but nothing in particular has stood out to me lately during the course of my work.

With that in mind, I figured I would take a different approach and see if anyone here had some specific requests for content they would like to see. Requests from all levels of experience are welcome!

(And for those who are itching to do a write-up on any of the requests that appear here, feel free to call dibs!)

Edit

For those who want to take a dive into my previous submissions, you can now find them in the new wiki entry created by @cfabbro or directly via the programming.code_quality_tips tag here.

Preface

It's not uncommon for a written piece of code to be both brief and functionality correct, yet difficult to reason about. This is especially true of recursive algorithms, which can require some amount of simulating the algorithm mentally (or on a whiteboard) on smaller problems to try to understand the underlying logic. The more you have to perform these manual simulations, the more difficult it becomes to track what exactly is going on at any stage of computation. It's also not uncommon that these algorithms can be made easier to reason about with relatively small changes, particularly in the way you conceptualize the solution to the problem. Our goal will be to take a brief tour into what these changes might look like and why they are effective at reducing our mental overhead.

Background

We will consider the case of the subset sum problem, which is essentially a special case of the knapsack problem where you have a finite number of each item and each item's value is equal to its weight. In short, the problem is summarized as one of the following:

• Given a set of numbers, is there a subset whose sum is exactly equal to some target value?

• Given a set of numbers, what is the subset whose sum is the closest to some target value without exceeding it?

For example, given the set of numbers {1, 3, 3, 5} and a target value of 9, the answer for both of those questions is {1, 3, 5} because the sum of those numbers is 9. For a target value of 10, however, the first question has no solution because no combination of numbers in the set {1, 3, 3, 5} produces a total of 10, but the second question produces a solution of {1, 3, 5} because 9 is the closest value to 10 that those numbers can produce without going over.

A Greedy Example

We'll stick to the much simpler case of finding an exact match to our target value so we don't have to track what the highest value found so far is. To make things even simpler, we'll consider the case where all numbers are positive, non-zero integers. This problem can be solved with some naive recursion--simply try all combinations until either a solution is found or all combinations have been exhausted. While more efficient solutions exist, naive recursion is the easiest to conceptualize.

An initial assessment of the problem seems simple enough. Our solution is defined as the set of array elements whose total is equal to our target value. To achieve this, we loop through each of the elements in the array, try combinations with all of the remaining elements, and keep track of what the current total is so we can compare it to our target. If we find an exact match, we return an array containing the matching elements, otherwise we return nothing. This gives us something like the following:

function subsetSum($target_sum, $values, $total = 0) {
    // Base case: a total exceeding our target sum is a failure.
    if($total > $target_sum) {
        return null;
    }

    // Base case: a total matching our target sum means we've found a match.
    if($total == $target_sum) {
        return array();
    }

    foreach($values as $index=>$value) {
        // Recursive case: try combining the current array element with the remaining elements.
        $result = subsetSum($target_sum, array_slice($values, $index + 1), $total + $value);

        if(!is_null($result)) {
            return array_merge(array($value), $result);
        }
    }

    return null;
}

Your Scope is Leaking

This solution works. It's functionally correct and will produce a valid result every single time. From a purely functional perspective, nothing is wrong with it at all; however, it's not easy to follow what's going on despite how short the code is. If we look closely, we can tell that there are a few major problems:

• It's not obvious at first glance whether or not the programmer is expected to provide the third argument. While a default value is provided, it's not clear if this value is only a default that should be overridden or if the value should be left untouched. This ambiguity means relying on documentation to explain the intention of the third argument, which may still be ignored by an inattentive developer.

• The base case where a failure occurs, i.e. when the accumulated total exceeds the target sum, occurs one stack frame further into the recursion than when the total has been incremented. This forces us to consider not only the current iteration of recursion, but one additional iteration deeper in order to track the flow of execution. Ideally an iteration of recursion should be conceptually isolated from any other, limiting our mental scope to only the current iteration.

• We're propagating an accumulating total that starts from 0 and increments toward our target value, forcing us to to track two different values simultaneously. Ideally we would only track one value if possible. If we can manage that, then the ambiguity of the third argument will be eliminated along with the argument itself.

Overall, the amount of code that the programmer needs to look at and the amount of branching they need to follow manually is excessive. The function is only 22 lines long, including whitespace and comments, and yet the amount of effort it takes to ensure you're understanding the flow of execution correctly is pretty significant. This is a pretty good indicator that we probably did something wrong. Something so simple and short shouldn't take so much effort to understand.

Patching the Leak

Now that we've assessed the problems, we can see that our original solution isn't going to cut it. We have a couple of ways we could approach fixing our function: we can either attempt to translate the abstract problems into tangible solutions or we can modify the way we've conceptualized the solution. With that in mind, let's take a second crack at this problem by trying the latter.

We've tried taking a look at this problem from a top-down perspective: "given a target value, are there any elements that produce a sum exactly equal to it?" Clearly this perspective failed us. Instead, let's try flipping the equation: "given an array element, can it be summed with others to produce the target value?"

This fundamentally changes the way we can think about the problem. Previously we were hung up on the idea of keeping track of the current total sum of the elements we've encountered so far, but that approach is incompatible with the way we're thinking of this problem now. Rather than incrementing a total, we now find ourselves having to do something entirely different: if we want to know if a given array element is part of the solution, we need to first subtract the element from the problem and find out if the smaller problem has a solution. That is, to find if the element 3 is part of the solution for the target sum of 8, then we're really asking if 3 + solutionFor(5) is valid.

The new solution therefore involves looping over our array elements just as before, but this time we check if there is a solution for the target sum minus the current array element:

function subsetSum($target_sum, $values) {
    // Base case: the solution to the target sum of 0 is the empty set.
    if($target_sum === 0) {
        return array();
    }

    foreach($values as $index=>$value) {
        // Base case: any element larger than our target sum cannot be part of the solution.
        if($value > $target_sum) {
            continue;
        }

        // Recursive case: do the remaining elements create a solution for the sub-problem?
        $result = subsetSum($target_sum - $value, array_slice($values, $index + 1));

        if(!is_null($result)) {
            return array_merge(array($value), $result);
        }
    }

    return null;
}

A Brief Review

With the changes now in place, let's compare our two functions and, more importantly, compare our new function to the problems we assessed with the original. A few brief points:

• Both functions are the same exact length, being only 22 lines long with the same number of comments and an identical amount of whitespace.

• Both functions touch the same number of elements and produce the same output given the same input. Apart from a change in execution order of a base case, functionality is nearly identical.

• The new function no longer requires thinking about the scope of next iteration of recursion to determine whether or not an array element is included in the result set. The base case for exceeding the target sum now occurs prior to recursion, keeping the scope of the value comparison nearest where those values are defined.

• The new function no longer uses a third accumulator argument, reducing the number of values to be tracked and removing the issue of ambiguity with whether or not to include the third argument in top-level calls.

• The new function is now defined in terms of finding the solutions to increasingly smaller target sums, making it easier to determine functional correctness.

Considering all of the above, we can confidently state that the second function is easier to follow, easier to verify functional correctness for, and less confusing for anyone who needs to use it. Although the two functions are nearly identical, the second version is clearly and objectively better than the original. This is because despite both being functionally correct, the first function does a poor job at accurately defining the problem it's solving while the second function is clear and accurate in its definition.

Correct code isn't necessarily accurate code. Anyone can write code that works, but writing code that accurately defines a problem can mean the difference between understanding what you're looking at, and being completely bewildered at how, or even why, your code works in the first place.

Final Thoughts

Accurately defining a problem in code isn't easy. Sometimes you'll get it right, but more often than not you'll get it wrong on the first go, and it's only after you've had some distance from you original solution that you realize that you should've done things differently. Despite that, understanding the difference between functional correctness and accuracy gives you the opportunity to watch for obvious inaccuracies and keep them to a minimum.

In the end, even functionally correct, inaccurate code is worth more than no code at all. No amount of theory is a replacement for practical experience. The only way to get better is to mess up, assess why you messed up, and make things just a little bit better the next time around. Theory just makes that a little easier.

Hi,

I've been mulling ideas about a game for a while now, I'd like to hack out a prototype, and my default would be Love2D. (As an aside: one of the things I like about Love2D was that you could make a basic 'game' in a couple of LoC, and it was 'efficient enough' for what you got. Perhaps the only gripe I had with it was that it didn't output compiled binaries (I mean, you could make it do that, but it seemed like a hack). I think Polycode seemed to be a semi-serious contender, but last I checked (a year or two ago) it's pretty much as dead as a doornail. Some of the other alternatives I remember seeing (Godot? Unity?) felt too much like Blender.

So I've been wondering, it's been a while since I've been keeping tabs on the 'gamedev community', so I don't know if there have been any more recent development in that space.

So I guess my question is: What are people using for game jams nowadays? Preach to me (and everyone else) about your favorite framework and language :)

In an effort to make these weekly, I present a new programming challenge.

The challenge this week is to compress some text using a prefix code. Prefix codes associate each letter with a given bit string, such that no encoded bitstring is the prefix of any other. These bit strings are then concatenated into one long integer which is separated into bytes for ease of reading. These bytes can be represented as hex values as well. The provided prefix encoding is as follows:

Challenge

Your program should accept a lowercase string (including the ~ character), and should output the formatted compressed bit string in binary and hex. Your final byte should be 0 padded so that it has 8 bits as required. For your convenience, here is the above table in a text file for easy read-in.

Example

Here is an example:

$> tildes ~comp
10010100 10010010 01011010 10111001 00000010 11000100 00110000 10100000
94 92 5A B9 02 C4 30 A0

Bonuses

1. Print the data compression ratio for a given compression, assuming the original input was encoded in 8 bit ASCII (one byte per character).
   2. Output the ASCII string corresponding to the encoded byte string in addition to the above outputs.
2. @onyxleopard points out that many bytes won't actually be valid ASCII. Instead, do as they suggested and treat each byte as an ordinal value and print it as if encoded as UTF-8.
3. An input prefixed by 'D' should be interpreted as an already compressed string using this encoding, and should be decompressed (by inverting the above procedure).

Previous Challenges (I am aware of prior existing ones, but it is hard to collect them as they were irregular. Thus I list last week's challenge as 'Week 1')
Week 1

Its been a while since we did one of these, which is a shame.

Create a program that takes is an input of the type: "d6 + 3" or "2d20 - 5", and return a valid roll.
The result should display both the actual rolls as well as the final result. The program should accept any valid roll of the type 'xdx'
Bonuses:

• Multiplication "d6 * 3"
• Division "d12 / 6"
• Polish notation "4d6 * (5d4 - 3)"

As a side note, it would be really cool if weekly programming challenges became a thing

Previous challenges

It's time for another coding challenge!

This challenge isn't mine, it's this challenge (year 5, season 3, challenge 3) by ČVUT FIKS.

The task is to design a network communication protocol. You're sending large amount of bits over the network. The problem is that network is not perfect and the message sometimes arrives corrupted. Design a network protocol, that will guarantee that the decoded message will be exactly same as the message that was encoded.

MESSAGE => (encoding) => message corrupted => (decoding) => MESSAGE

Corruption

Transmitting the message might corrupt it and introduce errors. Each error in a message (there might be more than one error in a single message) will flip all following bits of the message.

Example:

011101 => 011|010

(| is place where an error occured).

There might be more than one error in a message, but there are some rules:

• Minimum distance between two errors in a single message is k

• Number of bits between two errors is always odd number

According to these rules, describe a communication protocol, that will encode a message, and later decode message with errors.

Bonus

• Guarantee your protocol will work always - even when errors are as common as possible

• Try to make the protocol as short as possible.