I’ll answer this question incrementally. Let’s start with the = equivalence predicate. The = predicate is used to check whether two numbers are equal. If you supply it anything else but a number then it will raise an error: (= 2 3) => #f (= 2.5 2.5) => #t (= ‘() ‘()) => error The … Read more
A Y-combinator is a “functional” (a function that operates on other functions) that enables recursion, when you can’t refer to the function from within itself. In computer-science theory, it generalizes recursion, abstracting its implementation, and thereby separating it from the actual work of the function in question. The benefit of not needing a compile-time name … Read more
The term “referential transparency” comes from analytical philosophy, the branch of philosophy that analyzes natural language constructs, statements and arguments based on the methods of logic and mathematics. In other words, it is the closest subject outside computer science to what we call programming language semantics. The philosopher Willard Quine was responsible for initiating the … Read more
Yes, Swift has the Set class. let array1 = [“a”, “b”, “c”] let array2 = [“a”, “b”, “d”] let set1:Set<String> = Set(array1) let set2:Set<String> = Set(array2) Swift 3.0+ can do operations on sets as: firstSet.union(secondSet)// Union of two sets firstSet.intersection(secondSet)// Intersection of two sets firstSet.symmetricDifference(secondSet)// exclusiveOr Swift 2.0 can calculate on array arguments: set1.union(array2) // … Read more
If you want to get a feel for FRP, you could start with the old Fran tutorial from 1998, which has animated illustrations. For papers, start with Functional Reactive Animation and then follow up on links on the publications link on my home page and the FRP link on the Haskell wiki. Personally, I like … Read more
Variable scope When you declare a local variable, that variable has a scope. Generally, local variables exist only within the block or function in which you declare them. function() { var a = 1; console.log(a); // works } console.log(a); // fails If I try to access a local variable, most languages will look for it … Read more
1> L_tup = [ 1> {“Caerus1”, “Ramses Refiner”}, 1> {“Caerus1”, “Jupiter Refiner”}, 1> {“Caerus1”, “Jupiter Other”}, 1> {“Caerus1”, “Trader 13”}, 1> {“Caerus1”, “Cathode Supplier 4”}, 1> {“Dionysus3”, “Cathode Supplier 4”}, 1> {“Dionysus3”, “Ramses Refiner”}, 1> {“Dionysus3”, “Trader 13”}, 1> {“Dionysus3”, “Jupiter Refiner”}, 1> {“Dionysus3”, “Jupiter Other”}, 1> {“Prometheus2”, “Jupiter Other”}, 1> {“Prometheus2”, “Ramses Refiner”}, 1> … Read more