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What are the magic variables in CLISP REPL?

I noticed that when I type a statement in REPL, it often expands to a value that has something to do with the I / O history.

In particular, I noticed that:

  • + , ++ ... deploy to previous inputs,
  • * , ** ... expand to previous exits,
  • - expand to the current input

It seems like more ( / expands to something, but I didn't understand it for sure).

I tried to view detailed documents, but to no avail.

My questions:

  • What kind of REPL magic variables also exist? What are they doing?
  • Is there a way to access the nth input or output (e.g. IPython In and Out arrays)?
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2 answers

REPL variables are documented in the Hyperspec dictionary (search for "Variable"). The standard does not require more input / output than three, and I am not aware of any implementation that does this.

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As mentioned in another answer, these variables are documented in the ANSI Common Lisp standard.

In addition to the fact that the implementation of Common Lisp can have many other functions. A fully featured top level with a user interface is often called a Lisp listener.

The CLISP implementation provides additional commands in the debugger. See chapter 25 of your documentation.

LispWorks has some extensions in REPL and also provides a listener . Here are some examples:

Interaction number 2 in the CL-USER package:

 CL-USER 2 > (* 3 4) 12

Same thing, but we can omit the outer parentheses:

 CL-USER 3 > * 3 4 12

Let re-interaction 2:

 CL-USER 4 > :redo 2 (* 3 4) 12

Let re-interaction 2, but with division instead of multiplication:

 CL-USER 5 > :use / * 2 (/ 3 4) 3/4

Other implementations with extensions such as commands, output histories, or similar functions, such as Allegro CL and Clozure CL.

SLIME, which provides a common GNU Emacs-based Lisp development environment, also provides an advanced REPL .

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Source: https://habr.com/ru/post/1388913/

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