pkgs/development/lisp-modules/import/nix.lisp

   1 (defpackage org.lispbuilds.nix/nix
   2   (:documentation "Utilities for generating Nix code")
   3   (:use :cl)
   4   (:import-from :str)
   5   (:import-from :ppcre)
   6   (:import-from :arrow-macros :->>)
   7   (:import-from :org.lispbuilds.nix/util :replace-regexes)
   8   (:export
   9    :nix-eval
  10    :nixify-symbol
  11    :system-master
  12    :make-pname
  13    :*nix-attrs-depth*))
  14
  15 (in-package org.lispbuilds.nix/nix)
  16
  17 ;; Path names are alphanumeric and can include the symbols +-._?= and
  18 ;; must not begin with a period.
  19 (defun make-pname (string)
  20   (replace-regexes '("^[.]" "[^a-zA-Z0-9+-._?=]")
  21                    '("_" "_")
  22                    string))
  23
  24 (defun system-master (system)
  25   (first (str:split "/" system)))
  26
  27 ;;;; Nix generation
  28
  29 (defun nix-eval (exp)
  30   (assert (consp exp))
  31   (ecase (car exp)
  32     (:string (nix-string (cadr exp)))
  33     (:list (apply #'nix-list (rest exp)))
  34     (:funcall (apply #'nix-funcall (rest exp)))
  35     (:attrs (nix-attrs (cdr exp)))
  36     (:merge (apply #'nix-merge (cdr exp)))
  37     (:symbol (nix-symbol (cadr exp)))))
  38
  39 (defun nix-string (object)
  40   (format nil "\"~a\"" object))
  41
  42 (defun nixify-symbol (string)
  43   (flet ((fix-special-chars (str)
  44            (replace-regexes '("[_]" "[+]$" "[+][/]" "[+]" "[.]" "[/]")
  45                             '("__" "_plus" "_plus/" "_plus_" "_dot_" "_slash_")
  46                             str)))
  47     (if (ppcre:scan "^[0-9]" string)
  48         (str:concat "_" (fix-special-chars string))
  49         (fix-special-chars string))))
  50
  51
  52 (defun nix-symbol (object)
  53   (nixify-symbol (format nil "~a" object)))
  54
  55 (defun nix-list (&rest things)
  56   (format nil "[ ~{~A~^ ~} ]" (mapcar 'nix-eval things)))
  57 (defvar *nix-attrs-depth* 0)
  58
  59 (defun nix-attrs (keyvals)
  60   (when (null keyvals)
  61     (return-from nix-attrs "{}"))
  62   (let ((*nix-attrs-depth* (1+ *nix-attrs-depth*)))
  63     (format
  64      nil
  65      (->> "{~%*depth*~{~{~A = ~A;~}~^~%*depth*~}~%*depth-1*}"
  66           (str:replace-all "*depth*" (str:repeat *nix-attrs-depth* "  "))
  67           (str:replace-all "*depth-1*" (str:repeat (1- *nix-attrs-depth*) "  ")))
  68      (mapcar (lambda (keyval)
  69                (let ((key (car keyval))
  70                      (val (cadr keyval)))
  71                  (list (nix-symbol key)
  72                        (nix-eval val))))
  73              keyvals))))
  74
  75 (defun nix-funcall (fun &rest args)
  76   (format nil "(~a ~{~a~^ ~})"
  77           (nixify-symbol fun)
  78           (mapcar 'nix-eval args)))
  79
  80 (defun nix-merge (a b)
  81   (format nil "(~a // ~b)"
  82           (nix-eval a)
  83           (nix-eval b)))