Can I convert a string to enum without macros in Rust?

You should implement std::str::FromStr trait. use std::str::FromStr; #[derive(Debug, PartialEq)] enum Foo { Bar, Baz, Bat, Quux, } impl FromStr for Foo { type Err = (); fn from_str(input: &str) -> Result<Foo, Self::Err> { match input { “Bar” => Ok(Foo::Bar), “Baz” => Ok(Foo::Baz), “Bat” => Ok(Foo::Bat), “Quux” => Ok(Foo::Quux), _ => Err(()), } } } fn … Read more

Prolog getting head and tail of string

SWI-Prolog has several different representation of what you might call “strings”. List of character codes (Unicode); List of chars (one-letter atoms); Strings, which are “atomic” objects, and can be manipulated only with the built-in predicates for strings; And finally, of course, atoms. You should read the documentation, but for now, you have at least two … Read more

How do I find the last occurrence of a substring in a Swift string?

And if you want to replace the last substring in a string: (Swift 3) extension String { func replacingLastOccurrenceOfString(_ searchString: String, with replacementString: String, caseInsensitive: Bool = true) -> String { let options: String.CompareOptions if caseInsensitive { options = [.backwards, .caseInsensitive] } else { options = [.backwards] } if let range = self.range(of: searchString, options: … Read more

How to generate a random number in solidity?

Solidity contracts are deterministic. Anyone who figures out how your contract produces randomness can anticipate its results and use this information to exploit your application. One option is to produce randomness off-chain (where it cannot be predicted) and use it in your smart contract. Chainlink VRF is an easy-to-implement solution for using random data in … Read more

How to split a string by a string in Scala

The REPL is even easier than Stack Overflow. I just pasted your example as is. Welcome to Scala version (Java HotSpot Server VM, Java 1.6.0_22). Type in expressions to have them evaluated. Type :help for more information. scala> “string1::string2”.split(“::”) res0: Array[java.lang.String] = Array(string1, string2)