General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

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.

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

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.

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

General Programming Q&A thread! Ask any questions about programming, answer the questions of other users, or post suggestions for future threads.

Don't forget to format your code using the triple backticks or tildes:

Here is my schema:

```sql
CREATE TABLE article_to_warehouse (
  article_id   INTEGER
, warehouse_id INTEGER
)
;
```

How do I add a `UNIQUE` constraint?

I'm familiar with how the ranking algorithms work on a high level. What I'm curious about is to how those algorithms are actually applied.

How do these platforms actually apply the ranking algorithms so that the user sees the threads appropriately ordered? My knowledge is limited to PHP and MySQL, so I'm looking at it through the lense of those systems. I've thought of a few possible ways, but all of them seem pretty resource intensive.

1. Maintain a table of threads with all relevant information required to calculate ranking, as well as ranking itself. A server side script executing on a routine basis every X minutes (cron job?) updates the rankings on all the threads, so they can be easily ordered. However, people most likely don't care about threads >Y days old, so those can be excluded or automatically deranked somehow.

2. Maintain a table of threads with all relevant information required to calculate ranking. When a user visits, the last X threads (again, users probably don't care about really old stuff) are pulled out of the database and ran through a ranking and sorting algorithm, reordered and displayed to the user. This seems the most resource intensive?

I am by no means a professional developer, but I've been dabbling recently and the concept of how these large quantities of data are ranked both perplexes and interests me.

Been lurking for a week on tildes now and I am really glad this place exists. The crow here is exactly what I have been missing on Reddit for a while now.

Having said that, the whole Reddit situation has some-what motivated me to get the balls rolling on an idea that I have had for a while and I am looking for advice on the same.

I have often heard this phrase "Learn programming by building" but whenever I dive in to the resources, I fall flat due to the information overload and the general abstractness that the field has (I appreciate abstractness but here it demotivates me) and I have never found a proper resource that I could follow to actually build something instead of just blindly following tutorials and playing with them.

So, my question is how do I translate "learn by building a project" into a practical framework.

I know of 100 days of swift and I really like that approach however I don't think I want to start with swift or build an iOS app right now.

Lox is a toy programming language that is designed in Java and C at craftinginterpreters.com.

My challenge to you is: given the constraints of the Lox language, what are some creative or advanced programs you can create?

This page provides a rundown of the design of Lox.

To kick it off, here's a simple function that estimates the value of pi:

fun estimatePi(rounds) {
	var pi = 0;
	var alt = 1;
	for (var i = 0; i < rounds; i = i + 1) {
		pi = pi + alt * 4/(2 * i + 1);
		alt = -alt;
	}
	return pi;
}

print "The value of pi is:";
print getPi(100000);