[nongnu] elpa/nix-mode aaef8580c5 351/500: Merge pull request #86 from j-piecuch/smie-tweaks

[ELPA Syncer]

branch: elpa/nix-mode
commit aaef8580c5bbbfb8eb1c448aaf33bbe67b108f39
Merge: c577957d66 795cc0c4c5
Author: Matthew Bauer <mjbauer95@gmail.com>
Commit: GitHub <noreply@github.com>

    Merge pull request #86 from j-piecuch/smie-tweaks
    
    SMIE: parse paths enclosed in angle brackets (e.g. <nixpkgs>) correctly
---
 nix-mode.el             | 41 ++++++++++++++++++++++++++++++++++-------
 tests/nix-mode-tests.el | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+), 7 deletions(-)

diff --git a/nix-mode.el b/nix-mode.el
index e1dba6c1c9..96d3401370 100644
--- a/nix-mode.el
+++ b/nix-mode.el
@@ -527,22 +527,48 @@ STRING-TYPE type of string based off of Emacs syntax 
table types"
 
 (defconst nix-smie--path-chars "a-zA-Z0-9-+_.:/~")
 
-(defun nix-smie--skip-path (how)
+(defun nix-smie--skip-angle-path-forward ()
+  "Skip forward a path enclosed in angle brackets, e.g <nixpkgs>"
+  (let ((start (point)))
+    (when (eq (char-after) ?<)
+      (forward-char)
+      (if (and (nix-smie--skip-path 'forward t)
+               (eq (char-after) ?>))
+          (progn
+            (forward-char)
+            (buffer-substring-no-properties start (point)))
+        (ignore (goto-char start))))))
+
+(defun nix-smie--skip-angle-path-backward ()
+    "Skip backward a path enclosed in angle brackets, e.g <nixpkgs>"
+  (let ((start (point)))
+    (when (eq (char-before) ?>)
+      (backward-char)
+      (if (and (nix-smie--skip-path 'backward t)
+               (eq (char-before) ?<))
+          (progn
+            (backward-char)
+            (buffer-substring-no-properties start (point)))
+        (ignore (goto-char start))))))
+
+(defun nix-smie--skip-path (how &optional no-sep-check)
   "Skip path related characters."
   (let ((start (point)))
-    (pcase how
+    (pcase-exhaustive how
       ('forward (skip-chars-forward nix-smie--path-chars))
-      ('backward (skip-chars-backward nix-smie--path-chars))
-      (_ (error "expected 'forward or 'backward")))
+      ('backward (skip-chars-backward nix-smie--path-chars)))
     (let ((sub (buffer-substring-no-properties start (point))))
-      (if (string-match-p "/" sub)
+      (if (or (and no-sep-check
+                   (< 0 (length sub)))
+              (string-match-p "/" sub))
           sub
         (ignore (goto-char start))))))
 
 (defun nix-smie--forward-token-1 ()
   "Move forward one token."
   (forward-comment (point-max))
-  (or (nix-smie--skip-path 'forward)
+  (or (nix-smie--skip-angle-path-forward)
+      (nix-smie--skip-path 'forward)
       (buffer-substring-no-properties
        (point)
        (progn
@@ -563,7 +589,8 @@ STRING-TYPE type of string based off of Emacs syntax table 
types"
 (defun nix-smie--backward-token-1 ()
   "Move backward one token."
   (forward-comment (- (point)))
-  (or (nix-smie--skip-path 'backward)
+  (or (nix-smie--skip-angle-path-backward)
+      (nix-smie--skip-path 'backward)
       (buffer-substring-no-properties
        (point)
        (progn
diff --git a/tests/nix-mode-tests.el b/tests/nix-mode-tests.el
index f3e4a77b98..9bbeff713c 100644
--- a/tests/nix-mode-tests.el
+++ b/tests/nix-mode-tests.el
@@ -27,6 +27,44 @@
             (nix-mode)
             (eq (nix--get-string-type (nix--get-parse-state (point))) nil))))
 
+(ert-deftest nix-smie-angle-path-backward-detection ()
+  (should (with-temp-buffer
+            (nix-mode)
+            (insert "<nixpkgs/nixos>")
+            (nix-smie--skip-angle-path-backward)
+            (bobp))))
+
+(ert-deftest nix-smie-angle-path-backward-invalid ()
+  (should (with-temp-buffer
+            (nix-mode)
+            (insert "<nixpkgs/nixos>foo/bar>")
+            (null (nix-smie--skip-angle-path-backward)))))
+
+(ert-deftest nix-smie-angle-path-backward-early ()
+  (should (with-temp-buffer
+            (nix-mode)
+            (insert "<nixpkgs/nixos<foo/bar>")
+            (equal "<foo/bar>" (nix-smie--skip-angle-path-backward)))))
+
+(ert-deftest nix-smie-angle-path-forward-detection ()
+  (should (with-temp-buffer
+            (nix-mode)
+            (save-excursion (insert "<nixpkgs/nixos>"))
+            (nix-smie--forward-token)
+            (eobp))))
+
+(ert-deftest nix-smie-angle-path-forward-invalid ()
+  (should (with-temp-buffer
+            (nix-mode)
+            (save-excursion (insert "<nixpkgs/nixos<foo/bar>"))
+            (null (nix-smie--skip-angle-path-forward)))))
+
+(ert-deftest nix-smie-angle-path-forward-early ()
+  (should (with-temp-buffer
+            (nix-mode)
+            (save-excursion (insert "<foo/bar>nixpkgs/nixos>"))
+            (equal "<foo/bar>" (nix-smie--skip-angle-path-forward)))))
+
 ;;; Indentation tests
 
 (defvar nix-mode-test-dir (expand-file-name "testcases"