Interpreter

Interpreter

• Definition: An interpreter is a type of software program that directly executes high-level language (HLL) code written by programmers without translating it into machine code first.

Functionality of Interpreter

• Line-By-Line Execution: Interpreters execute source code line by line. They read, translate, and execute each individual instruction instead of translating the entire program at once.

• Immediate Feedback: As interpreters execute code one line at a time, they provide instant feedback by flagging syntax or semantic errors as soon as they occur. This allows for immediate error correction by the programmer.

• Running Scripts: Interpreters are beneficial for running scripts, where they read and execute code dynamically.

• Non-Compilation: They don’t generate an independently executable file. The interpreter and the source code are required each time the program is run.

Types of Interpreter

• Bytecode Interpreters: These first translate the source code into a middle language or bytecode which is then executed. Some examples would be Python and Java’s JVM.

• AST Interpreters: Abstract Syntax Tree (AST) interpreters to scan, parse and build a tree-like data structure. Languages like JavaScript can use this method.

• Threaded Code Interpreters: These convert each high-level code operation into a sequence of machine code instructions, stored in the form of a procedure or subroutine.

Advantages of Interpreter

• Ease of Debugging: As interpreters spot errors as soon as they occur, this allows immediate debugging and is therefore more user-friendly.

• Portability: The same code can be run on different machines with relevant interpreter, making it portable.

Disadvantages of Interpreter

• Speed: Interpreters are comparatively slower as they process the source code each time the program is run.

• Lack of Protection: Since the source code is needed every time you run the program, it can expose the program to possible unauthorised access and modifications.