emacs-29 5a6dfab1e4 2/2: Use c-ts-common-statement-offset in java-ts-mode (bug#61142)

[Theodor Thornhill]

branch: emacs-29
commit 5a6dfab1e4d5d89e5d5ff3bef73279926f067dbc
Author: Theodor Thornhill <theo@thornhill.no>
Commit: Theodor Thornhill <theo@thornhill.no>

    Use c-ts-common-statement-offset in java-ts-mode (bug#61142)
    
    * lisp/progmodes/java-ts-mode.el (java-ts-mode--indent-rules): Add new
    matchers to enable c-ts-common machinery.
    (java-ts-mode): Add regexps.
    * lisp/progmodes/c-ts-common.el (c-ts-common-statement-offset): Fix
    typo in documentation and use the new if statement helpers.
    (c-ts-common-if-statement-regexp): New defvar.
    (c-ts-common-nestable-if-statement-p): New defvar.
    (c-ts-common--fix-nestable-if-statement): New helper.
    * test/lisp/progmodes/c-ts-mode-resources/indent.erts: Add test for
    complicated bracket matching indentation.
    * lisp/progmodes/c-ts-mode.el (c-ts-mode--indent-styles): Add indent
    rules for bracketless statements.
---
 lisp/progmodes/c-ts-common.el                      | 34 +++++++++++++++-
 lisp/progmodes/c-ts-mode.el                        |  7 ++++
 lisp/progmodes/java-ts-mode.el                     | 36 ++++++++++++-----
 .../lisp/progmodes/c-ts-mode-resources/indent.erts | 45 ++++++++++++++++++++++
 4 files changed, 112 insertions(+), 10 deletions(-)

diff --git a/lisp/progmodes/c-ts-common.el b/lisp/progmodes/c-ts-common.el
index 8729cae4ba..6767f10a9e 100644
--- a/lisp/progmodes/c-ts-common.el
+++ b/lisp/progmodes/c-ts-common.el
@@ -281,11 +281,22 @@ special handling from our bracket-counting indent 
algorithm.
 
 This can be nil, meaning such special handling is not needed.")
 
+(defvar c-ts-common-if-statement-regexp "if_statement"
+  "Regexp used to select an if statement in a C like language.
+
+This can be set to a different regexp if needed.")
+
+(defvar c-ts-common-nestable-if-statement-p t
+  "Does the current parser nest if-else statements?
+
+t if the current tree-sitter grammar nests the else if
+statements, nil otherwise.")
+
 (defun c-ts-common-statement-offset (node parent bol &rest _)
   "This anchor is used for children of a statement inside a block.
 
 This function basically counts the number of block nodes (i.e.,
-brackets) (defined by `c-ts-mode--indent-block-type-regexp')
+brackets) (defined by `c-ts-common-indent-block-type-regexp')
 between NODE and the root node (not counting NODE itself), and
 multiply that by `c-ts-common-indent-offset'.
 
@@ -312,6 +323,9 @@ characters on the current line."
     (while (if (eq node t)
                (setq node parent)
              node)
+      ;; Subtract one indent level if the language nests
+      ;; if-statements and node is if_statement.
+      (setq level (c-ts-common--fix-nestable-if-statement level node))
       (when (string-match-p c-ts-common-indent-block-type-regexp
                             (treesit-node-type node))
         (cl-incf level)
@@ -354,6 +368,24 @@ the bracket in the body."
         (1+ level)
       level)))
 
+(defun c-ts-common--fix-nestable-if-statement (level node)
+  "Takes LEVEL and NODE and return adjusted LEVEL.
+Look at the type of NODE, when it is an if-statement node, as
+defined by `c-ts-common-if-statement-regexp' and its parent is
+also an if-statement node, subtract one level.  Otherwise return
+the value unchanged.  Whether or not if-statements are nestable
+is controlled by `c-ts-common-nestable-if-statement-p'."
+  ;; This fixes indentation for cases shown in bug#61142.
+  (or (and node
+           (equal (treesit-node-type (treesit-node-prev-sibling node)) "else")
+           (treesit-node-parent node)
+           c-ts-common-nestable-if-statement-p
+           (equal (treesit-node-type node) c-ts-common-if-statement-regexp)
+           (equal (treesit-node-type (treesit-node-parent node))
+                  c-ts-common-if-statement-regexp)
+           (cl-decf level))
+      level))
+
 (provide 'c-ts-common)
 
 ;;; c-ts-common.el ends here
diff --git a/lisp/progmodes/c-ts-mode.el b/lisp/progmodes/c-ts-mode.el
index 3740130be3..9381608166 100644
--- a/lisp/progmodes/c-ts-mode.el
+++ b/lisp/progmodes/c-ts-mode.el
@@ -238,6 +238,13 @@ MODE is either `c' or `cpp'."
            ((parent-is "labeled_statement")
             point-min c-ts-common-statement-offset)
 
+           ;; Bracketless statement matchers.
+           ((match nil "while_statement" "condition") parent-bol 
c-ts-mode-indent-offset)
+           ((match nil "if_statement" "consequence") parent-bol 
c-ts-mode-indent-offset)
+           ((match nil "if_statement" "alternative") parent-bol 
c-ts-mode-indent-offset)
+           ((match nil "do_statement" "body") parent-bol 
c-ts-mode-indent-offset)
+           ((match nil "for_statement" "body") parent-bol 
c-ts-mode-indent-offset)
+
            ((match "preproc_ifdef" "compound_statement") point-min 0)
            ((match "#endif" "preproc_ifdef") point-min 0)
            ((match "preproc_if" "compound_statement") point-min 0)
diff --git a/lisp/progmodes/java-ts-mode.el b/lisp/progmodes/java-ts-mode.el
index b9f7894095..1d7bdb0722 100644
--- a/lisp/progmodes/java-ts-mode.el
+++ b/lisp/progmodes/java-ts-mode.el
@@ -70,22 +70,25 @@
 (defvar java-ts-mode--indent-rules
   `((java
      ((parent-is "program") point-min 0)
-     ((node-is "}") (and parent parent-bol) 0)
+     ((match "}" "element_value_array_initializer")
+      parent-bol 0)
+     ((node-is "}") point-min c-ts-common-statement-offset)
      ((node-is ")") parent-bol 0)
+     ((node-is "else") parent-bol 0)
      ((node-is "]") parent-bol 0)
      ((and (parent-is "comment") c-ts-common-looking-at-star)
       c-ts-common-comment-start-after-first-star -1)
      ((parent-is "comment") prev-adaptive-prefix 0)
      ((parent-is "text_block") no-indent)
-     ((parent-is "class_body") parent-bol java-ts-mode-indent-offset)
+     ((parent-is "class_body") point-min c-ts-common-statement-offset)
      ((parent-is "array_initializer") parent-bol java-ts-mode-indent-offset)
-     ((parent-is "annotation_type_body") parent-bol java-ts-mode-indent-offset)
-     ((parent-is "interface_body") parent-bol java-ts-mode-indent-offset)
-     ((parent-is "constructor_body") parent-bol java-ts-mode-indent-offset)
+     ((parent-is "annotation_type_body") point-min 
c-ts-common-statement-offset)
+     ((parent-is "interface_body") point-min c-ts-common-statement-offset)
+     ((parent-is "constructor_body") point-min c-ts-common-statement-offset)
      ((parent-is "enum_body_declarations") parent-bol 0)
-     ((parent-is "enum_body") parent-bol java-ts-mode-indent-offset)
-     ((parent-is "switch_block") parent-bol java-ts-mode-indent-offset)
-     ((parent-is "record_declaration_body") parent-bol 
java-ts-mode-indent-offset)
+     ((parent-is "enum_body") point-min c-ts-common-statement-offset)
+     ((parent-is "switch_block") point-min c-ts-common-statement-offset)
+     ((parent-is "record_declaration_body") point-min 
c-ts-common-statement-offset)
      ((query "(method_declaration (block _ @indent))") parent-bol 
java-ts-mode-indent-offset)
      ((query "(method_declaration (block (_) @indent))") parent-bol 
java-ts-mode-indent-offset)
      ((parent-is "local_variable_declaration") parent-bol 
java-ts-mode-indent-offset)
@@ -118,7 +121,7 @@
      ((parent-is "case_statement") parent-bol java-ts-mode-indent-offset)
      ((parent-is "labeled_statement") parent-bol java-ts-mode-indent-offset)
      ((parent-is "do_statement") parent-bol java-ts-mode-indent-offset)
-     ((parent-is "block") (and parent parent-bol) java-ts-mode-indent-offset)))
+     ((parent-is "block") point-min c-ts-common-statement-offset)))
   "Tree-sitter indent rules.")
 
 (defvar java-ts-mode--keywords
@@ -300,6 +303,21 @@ Return nil if there is no name or if NODE is not a defun 
node."
   (c-ts-common-comment-setup)
 
   ;; Indent.
+  (setq-local c-ts-common-indent-block-type-regexp
+              (regexp-opt '("class_body"
+                            "array_initializer"
+                            "constructor_body"
+                            "annotation_type_body"
+                            "interface_body"
+                            "enum_body"
+                            "switch_block"
+                            "record_declaration_body"
+                            "block")))
+  (setq-local c-ts-common-indent-bracketless-type-regexp
+              (regexp-opt '("if_statement"
+                            "for_statement"
+                            "while_statement")))
+  (setq-local c-ts-common-indent-offset 'java-ts-mode-indent-offset)
   (setq-local treesit-simple-indent-rules java-ts-mode--indent-rules)
 
   ;; Electric
diff --git a/test/lisp/progmodes/c-ts-mode-resources/indent.erts 
b/test/lisp/progmodes/c-ts-mode-resources/indent.erts
index 7dcc3b0fb3..6f64e1e795 100644
--- a/test/lisp/progmodes/c-ts-mode-resources/indent.erts
+++ b/test/lisp/progmodes/c-ts-mode-resources/indent.erts
@@ -244,3 +244,48 @@ int main() {
     }
 }
 =-=-=
+
+Name: Complicated mixed bracket matching indentation (bug#61142)
+
+=-=
+void foo(
+         int foo) {
+  for (;;)
+    return 5;
+
+  if (a == 0
+      && b == 1
+      && foo)
+    {
+      return 0;
+    }
+  else if (a == 1)
+    {
+      return 1;
+    }
+  else if (true)
+    return 5;
+  else
+    {
+      if (a == 0
+          && b == 1
+          && foo)
+        for (
+             int i = 0;
+             i < 5;
+             i++)
+          if (true)
+            do
+              i = 5;
+            while (true);
+          else if (false)
+            {
+              return 6;
+            }
+          else
+            if (true
+                && false)
+              return 6;
+    }
+}
+=-=-=