Set Comprehension

What’s a set comprehension?

• An expression that evaluates to a set
• A feature of some programming languages (e.g., Python) What does a set comprehension look like?
• $x|p(x)$ all x such that p(x) is true
• $x\in N|p(x)$ all natural numbers that satisfy p(x)
• $x\in [\mathrm{1...100}]|x\%2=0$ all even numbers up to 100
• $\text{x for x in range(1, 100) if }x\%2==0$ Python version

How does a compiler process a set comprehension?

• Generate a loop over the domain of objects