[nongnu] elpa/nix-mode 5a29112764 073/500: Add function for escaped antiquote.

[ELPA Syncer]

branch: elpa/nix-mode
commit 5a291127640c967364aeda8c798e17d48c7559f2
Author: Matthew Bauer <mjbauer95@gmail.com>
Commit: Matthew Bauer <mjbauer95@gmail.com>

    Add function for escaped antiquote.
    
    This function detects when it's right to ignore or use the ''${ as an 
antiquote.
---
 nix-mode.el | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/nix-mode.el b/nix-mode.el
index 58148de03f..d995504b4b 100644
--- a/nix-mode.el
+++ b/nix-mode.el
@@ -135,6 +135,26 @@ If a close brace `}' ends an antiquote, the next character 
begins a string."
        (put-text-property start (1+ start)
                           'nix-syntax-antiquote t)))))
 
+(defun nix-syntax-propertize-escaped-antiquote ()
+  "Set syntax properties for escaped antiquote."
+  (let* ((start (match-beginning 0))
+         (context (save-excursion (save-match-data (syntax-ppss start))))
+         (string-type (nth 3 context)))
+
+    ;; treat like multiline when not already in string
+    ;; else ignore
+    (when (not string-type)
+      (put-text-property start (1+ start)
+                        'syntax-table (string-to-syntax "|"))
+
+      (when (string= (buffer-substring (+ 2 start) (+ 4 start)) "${")
+       (put-text-property (+ 2 start) (+ 3 start)
+                          'syntax-table (string-to-syntax "|"))
+       (put-text-property (+ 2 start) (+ 4 start)
+                          'nix-syntax-antiquote t))
+      )
+    ))
+
 (defun nix-syntax-propertize (start end)
   "Special syntax properties for Nix from START to END."
   ;; search for multi-line string delimiters
@@ -143,7 +163,7 @@ If a close brace `}' ends an antiquote, the next character 
begins a string."
   (funcall
    (syntax-propertize-rules
     ("''['\\$\]" ;; ignore ''* characters
-     (0 (ignore (lambda () nil))))
+     (0 (ignore (nix-syntax-propertize-escaped-antiquote))))
     ("''"
      (0 (ignore (nix-syntax-propertize-multiline-string))))
     ("\\${"