REPL
/rɛpəl/ · Abbreviation · Noun · Development · Origin: 1960
Definitions
Read-Eval-Print Loop — an interactive programming environment that takes single expressions, evaluates them, and returns the result immediately. Originated with Lisp and now standard in most dynamic languages.
In plain English: An interactive window where you can type code and immediately see what it does — like having a conversation with the programming language.
Etymology
- c. 1960
- Lisp introduces the Read-Eval-Print Loop on the IBM 704, becoming the first language with an interactive interpreter
- 1964
- The term REPL crystallizes in the Lisp community; interactive computing becomes a core value of MIT's AI Lab
- 2010s
- REPLs become standard in modern languages; browser developer consoles bring the concept to every web developer