Programming Languages: Concepts and Implementation

10.4 Preliminaries: Interpreter Essentials

Building an interpreter for a computer language involves defining the following elements:

1. A Read-Eval-Print Loop (REPL): a user interface that reads program strings and passes them to the front end of the interpreter

2. A Front End: a source code parser that translates a string representing a program into an abstract-syntax representation—usually a tree—of the program, sometimes referred to as bytecode

3. An Interpreter:¹ an expression evaluation function or loop that traverses and interprets an abstract-syntax representation of the program

4. Supporting Data Types/Structures and Libraries: a suite of abstract data types (e.g., an environment, closure, and reference) and associated functions to support the ...