What does REPL mean in Unclassified?

Read–eval–print loop

A read–eval–print loop is a simple, interactive computer programming environment. The term is most usually used to refer to a Lisp interactive environment, but can be applied to command line shells and similar environments for programming languages such as APL, BASIC, Clojure, F#, Haskell, J, Julia, Perl, PHP, Prolog, Python, R, Ruby, Scala, Smalltalk, Standard ML, Tcl, Javascript, et al. Synonyms include interactive toplevel and language shell. In a REPL, the user enters one or more expressions, which are then evaluated, and the results displayed. The name read–eval–print loop comes from the names of the Lisp primitive functions which implement this functionality: ⁕The read function accepts an expression from the user, and parses it into a data structure in memory. For instance, the user may enter the s-expression, which is parsed into a linked list containing four data elements. ⁕The eval function takes this internal data structure and evaluates it. In Lisp, evaluating an s-expression beginning with the name of a function means calling that function on the arguments that make up the rest of the expression. So the function + is called on the arguments 1 2 3, yielding the result 6.

see more »