Feature: optionally preserve blank lines between struct fields

README.md

@@ -193,6 +193,8 @@ Options:
 
 - `multiline_composite_literals`: When enabled, composite literals that were written across multiple lines are kept multiline.
 
+- `preserve_struct_blank_lines`: Preserve blank lines between struct fields, up to `newline_limit`.
+
 ## Features
 
 Support Language server features:

misc/odinfmt.schema.json

@@ -95,6 +95,11 @@
 			"type": "boolean",
 			"default": false,
 			"description": "Composite literals that span multiple lines are not forcibly inlined"
+		},
+		"preserve_struct_blank_lines": {
+			"type": "boolean",
+			"default": false,
+			"description": "Preserve blank lines between struct fields, up to newline_limit"
 		}
 	},
 	"required": []

src/odin/printer/printer.odin

@@ -72,6 +72,7 @@ Config :: struct {
 	align_constant_definitions:   bool,
 	align_comments:               bool, //Align trailing line comments to the same column.
 	multiline_composite_literals: bool,
+	preserve_struct_blank_lines:  bool,
 }
 
 Brace_Style :: enum {
@@ -127,6 +128,7 @@ when ODIN_OS == .Windows {
 		align_constant_definitions   = false,
 		align_comments               = false,
 		multiline_composite_literals = false,
+		preserve_struct_blank_lines  = false,
 	}
 } else {
 	default_style := Config {
@@ -147,6 +149,7 @@ when ODIN_OS == .Windows {
 		align_constant_definitions   = false,
 		align_comments               = false,
 		multiline_composite_literals = false,
+		preserve_struct_blank_lines  = false,
 	}
 }
 

src/odin/printer/visit.odin

@@ -2219,8 +2219,12 @@ visit_struct_field_list :: proc(p: ^Printer, list: ^ast.Field_List, options := L
 		}
 
 		if i != len(list.list) - 1 && .Enforce_Newline in options {
-			comment, _ := visit_comments(p, list.list[i + 1].pos)
-			document = cons(document, comment, newline(1))
+			if p.config.preserve_struct_blank_lines {
+				document = cons(document, move_line(p, list.list[i + 1].pos))
+			} else {
+				comment, _ := visit_comments(p, list.list[i + 1].pos)
+				document = cons(document, comment, newline(1))
+			}
 		} else {
 			comment, _ := visit_comments(p, list.end)
 			document = cons(document, comment)

tools/odinfmt/tests/collapse_struct_field_blank_lines/.snapshots/structs.odin

@@ -0,0 +1,6 @@
+package collapse_struct_field_blank_lines
+
+Pair :: struct {
+	first:  int,
+	second: int,
+}

tools/odinfmt/tests/collapse_struct_field_blank_lines/structs.odin

@@ -0,0 +1,7 @@
+package collapse_struct_field_blank_lines
+
+Pair :: struct {
+	first: int,
+
+	second: int,
+}

tools/odinfmt/tests/preserve_struct_field_blank_lines/.snapshots/structs.odin

@@ -0,0 +1,27 @@
+package preserve_struct_field_blank_lines
+
+Settings :: struct {
+	window_width:  int,
+	window_height: int,
+	target_fps:    int,
+
+	fullscreen:    bool,
+	vertical_sync: bool,
+}
+
+With_Comments :: struct {
+	first:  int, // trailing comment
+
+	// The second group.
+	second: int,
+
+	// The third group follows this comment without a blank line.
+	third:  int,
+}
+
+Capped_By_Newline_Limit :: struct {
+	first:  int,
+
+
+	second: int,
+}

tools/odinfmt/tests/preserve_struct_field_blank_lines/odinfmt.json

@@ -0,0 +1,4 @@
+{
+	"newline_limit": 2,
+	"preserve_struct_blank_lines": true
+}

tools/odinfmt/tests/preserve_struct_field_blank_lines/structs.odin

@@ -0,0 +1,29 @@
+package preserve_struct_field_blank_lines
+
+Settings :: struct {
+	window_width:  int,
+	window_height: int,
+	target_fps:    int,
+
+	fullscreen:   bool,
+	vertical_sync: bool,
+}
+
+With_Comments :: struct {
+	first: int, // trailing comment
+
+	// The second group.
+	second: int,
+
+	// The third group follows this comment without a blank line.
+	third: int,
+}
+
+Capped_By_Newline_Limit :: struct {
+	first: int,
+
+
+
+
+	second: int,
+}