branch: elpa/nix-mode
commit a4e65609023f1d06a76f7a75716d860bd27cfb68
Author: Matthew Bauer <[email protected]>
Commit: Matthew Bauer <[email protected]>
Add nix-instantiate.el
---
nix-instantiate.el | 100 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 100 insertions(+)
diff --git a/nix-instantiate.el b/nix-instantiate.el
new file mode 100644
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+++ b/nix-instantiate.el
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+;;; nix-instantiate.el -- run nix commands in Emacs -*- lexical-binding: t -*-
+
+;; Author: Matthew Bauer <[email protected]>
+;; Homepage: https://github.com/NixOS/nix-mode
+;; Keywords: nix
+
+;; This file is NOT part of GNU Emacs.
+
+;;; Commentary:
+
+;;; Code:
+
+(require 'nix)
+(require 'json)
+
+(defun nix-instantiate--parsed (drv)
+ "Get the parsed version of the .drv file.
+DRV file to load from."
+ (let ((stdout (generate-new-buffer "nix show-derivation")))
+ (call-process nix-executable nil (list stdout nil) nil
+ "show-derivation" drv)
+ (cdar (with-current-buffer stdout
+ (when (eq (buffer-size) 0)
+ (error
+ "Error: nix show-derivation %s failed to produce any output"
+ drv))
+ (goto-char (point-min))
+ (json-read)))))
+
+;;;###autoload
+(defun nix-instantiate (nix-file &optional attribute)
+ "Run nix-instantiate on a Nix expression.
+NIX-FILE the file to instantiate.
+ATTRIBUTE an attribute of the Nix file to use."
+ (interactive "fNix file: ")
+ (setq nix-file (expand-file-name nix-file))
+ (let ((stdout (generate-new-buffer "nix-instantiate"))
+ result)
+ (if attribute
+ (call-process nix-instantiate-executable nil (list stdout nil) nil
+ nix-file "-A" attribute)
+ (call-process nix-instantiate-executable nil (list stdout nil) nil
+ nix-file))
+ (with-current-buffer stdout
+ (when (eq (buffer-size) 0)
+ (error
+ "Error: nix-instantiate %s failed to produce any output"
+ nix-file))
+ (setq result (nix-instantiate--parsed
+ (substring (buffer-string) 0 (- (buffer-size) 1)))))
+ (kill-buffer stdout)
+ result))
+
+(defvar nix-instantiate--running-processes nil)
+
+(defun nix-instantiate--sentinel (prop err proc event)
+ "Make a nix-instantiate process.
+PROP the prop name of nix-instantiate--running-processes.
+ERR the error buffer.
+PROC the process that has been run.
+EVENT the event that was fired."
+ (when (string= event "finished\n")
+ (with-current-buffer (process-buffer proc)
+ (unless (eq (buffer-size) 0)
+ (let ((drv (nix-instantiate--parsed
+ (substring (buffer-string) 0 (- (buffer-size) 1)))))
+ (dolist
+ (callback (lax-plist-get nix-instantiate--running-processes prop))
+ (funcall callback drv)))))
+ (setq nix-instantiate--running-processes
+ (lax-plist-put nix-instantiate--running-processes prop nil))
+ (kill-buffer (process-buffer proc))
+ (kill-buffer err)))
+
+;;;###autoload
+(defun nix-instantiate-async (callback nix-file &optional attribute)
+ "Run nix-instantiate on a Nix expression, asynchronously.
+CALLBACK the function to call when instantiate completes.
+NIX-FILE the file to instantiate
+ATTRIBUTE an attribute of the Nix file to use."
+ (setq nix-file (expand-file-name nix-file))
+ (let* ((prop (if attribute
+ (expand-file-name attribute nix-file) nix-file))
+ (data (lax-plist-get nix-instantiate--running-processes prop))
+ (stdout (generate-new-buffer "nix-instantiate"))
+ (stderr (generate-new-buffer "nix-instantiate error")))
+ (setq nix-instantiate--running-processes
+ (lax-plist-put nix-instantiate--running-processes
+ prop (cons callback data)))
+ (make-process
+ :name "nix-instantiate"
+ :buffer stdout
+ :command (append (list nix-instantiate-executable nix-file)
+ (when attribute ("-A" attribute)))
+ :noquery t
+ :sentinel (apply-partially 'nix-instantiate--sentinel prop stderr)
+ :stderr stderr)))
+
+(provide 'nix-instantiate)
+;;; nix-instantiate.el ends here
