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REPL is a Read Eval Print Loop, which is a way to interact with a Lisp runtime. This is independent on how EVAL is implemented. A bunch of Lisp systems implemen

by lispm 4y ago

REPL is a Read Eval Print Loop, which is a way to interact with a Lisp runtime. This is independent on how EVAL is implemented. A bunch of Lisp systems implement EVAL with an incremental compiler. An interpreter is a Lisp feature where code gets interpreted from source at runtime. Some implementations have one, some don't, some only have an interpreter, some only have a compiler, some have several compilers, some have both. > running sbcl without the REPL and produce an executable binary file The executable binary file in SBCL always includes the compiler. REPL: a user interface to execute Lisp code. Reads s-expressions, evaluates them and prints the results as s-expressions. EVAL: the interface to execute code. A function. Interpreter: an implementation of Lisp which interprets source code. Byte Code Interpreter: an implementation of Lisp which interprets byte code instructions. Compiler: an implementation of Lisp which can compile code to a) byte code, b) C code, c) machine code In-memory compiler: an implementation of Lisp where the compiler does not create files, but writes the executable code directly to RAM Whole-Program compiler: an implementation of Lisp, which only compiles whole programs and creates executables -> rare, but various examples exists

terminalcommand 4y ago
Thank you for taking the time to explain. I now get it. SBCL includes the compiler in each binary and this is called incremental compiling. That explains the expressiveness. It is kind of like a JIT when needed. Compile everything you can AoT, leave dynamic parts to runtime compilation. It makes perfect sense. Thanks . I guess the difference is that in an interpreter you don't go down to assembly, you parse and run stuff. The moment you cross the line to generate bytecode/machine code or transpile into a different language you get a compiler.
- lispm 4y ago
  Basically all SBCL code is pre-compiled. There is mostly no runtime compilation happening. Only if the user/developer actually wants it. For example one can connect to a running SBCL and have one or more networked REPLs into it.

by lispm 4y ago

terminalcommand 4y ago

Thank you for taking the time to explain. I now get it. SBCL includes the compiler in each binary and this is called incremental compiling. That explains the expressiveness. It is kind of like a JIT when needed. Compile everything you can AoT, leave dynamic parts to runtime compilation. It makes perfect sense. Thanks . I guess the difference is that in an interpreter you don't go down to assembly, you parse and run stuff. The moment you cross the line to generate bytecode/machine code or transpile into a different language you get a compiler.

lispm 4y ago
Basically all SBCL code is pre-compiled. There is mostly no runtime compilation happening. Only if the user/developer actually wants it. For example one can connect to a running SBCL and have one or more networked REPLs into it.