Common Lisp bindings to GNU Readline library.

The Readline library provides a set of functions for use by applications that allow users to edit command lines as they are typed in. Both Emacs and vi editing modes are available. The Readline library includes additional functions to maintain a list of previously-entered command lines, to recall and perhaps reedit those lines, and perform csh-like history expansion on previous commands.

These bindings provide Lispy interface to GNU Readline somewhat reducing its hair. Some minor features are omitted, they may be added on request. Open an issue if you have any propositions.

GitHub repository:

You can install it via Quicklisp:

(ql:quickload "cl-readline")

I created this bindings because Linedit didn't work for me and I love GNU and GNU GPL. Also, Linedit doesn't have decent documentation, that README file describing 4 functions doesn't count. So I did my best to write proper documentation too.

Here is an example of cl-readline in action:

;;; Load some systems and define a package... (asdf:load-system :alexandria) (asdf:load-system :cl-readline) (cl:defpackage :example (:use #:common-lisp #:alexandria) (:export #:run-example)) (in-package :example) ;;; Now let's define lists of verbs and fruits: (defvar *verbs* '("eat" "get" "throw" "quit")) (defvar *fruits* '("banana" "apple" "orange" "banana_two")) ;;; Define and register function that does custom completion: if user enters ;;; first word, it will be completed as a verb, second and later words will ;;; be completed as fruits. (defun custom-complete (text start end) (declare (ignore end)) (labels ((common-prefix (items) (subseq (car items) 0 (position nil (mapcar (lambda (i) (every (lambda (x) (char= (char (car items) i) (char x i))) (cdr items))) (iota (reduce #'min (mapcar #'length items))))))) (select-completions (list) (let ((els (remove-if-not (curry #'starts-with-subseq text) list))) (if (cdr els) (cons (common-prefix els) els) els)))) (if (zerop start) (select-completions *verbs*) (select-completions *fruits*)))) (rl:register-function :complete #'custom-complete) ;;; Let's also create a custom command and bind it to some key sequence so ;;; user can invoke it. In this example user can automagically insert phrase ;;; 'inserted text' pressing Control-o. (defun print-some-text (arg key) (declare (ignore arg key)) (rl:insert-text "inserted text")) (rl:bind-keyseq "\\C-o" #'print-some-text) ;;; Let's write novelty-check, so if the actual line is equal to the most ;;; recent history line it will not be added to the history. (defun novelty-check (x y) (string/= (string-trim " " x) (string-trim " " y))) ;;; Finally, this is our main function. To exit from the loop, enter 'quit'. (defun run-example () (do ((i 0 (1+ i)) (text "")) ((string= "quit" (string-trim " " text))) (setf text (rl:readline :prompt (format nil "[~a]> " i) :add-history t :novelty-check #'novelty-check))))

cl-readline is written and maintained by Mark Karpov.

It's distributed under GNU GPL.

Relevant topics: library, text, console