fmt: implement comments inside sumtype declaration (#18189)

Author: yuyi98

cmd/tools/vast/vast.v

@@ -804,7 +804,6 @@ fn (t Tree) sum_type_decl(node ast.SumTypeDecl) &Node {
 	obj.add('pos', t.pos(node.pos))
 	obj.add_terse('typ', t.type_node(node.typ))
 	obj.add_terse('generic_types', t.array_node_type(node.generic_types))
-	obj.add('comments', t.array_node_comment(node.comments))
 	obj.add_terse('variants', t.array_node_type_expr(node.variants))
 	obj.add('name_pos', t.pos(node.name_pos))
 	return obj

vlib/v/ast/ast.v

@@ -114,7 +114,8 @@ pub struct TypeNode {
 pub:
 	pos token.Pos
 pub mut:
-	typ Type
+	typ          Type
+	end_comments []Comment // comments that after current type node
 }
 
 pub enum ComptimeTypeKind {
@@ -1335,7 +1336,6 @@ pub:
 	is_pub        bool
 	pos           token.Pos
 	name_pos      token.Pos
-	comments      []Comment
 	typ           Type
 	generic_types []Type
 	attrs         []Attr // attributes of type declaration

vlib/v/fmt/fmt.v

@@ -1469,6 +1469,11 @@ pub fn (mut f Fmt) fn_type_decl(node ast.FnTypeDecl) {
 	f.writeln('')
 }
 
+struct Variant {
+	name string
+	id   int
+}
+
 pub fn (mut f Fmt) sum_type_decl(node ast.SumTypeDecl) {
 	f.attrs(node.attrs)
 	start_pos := f.out.len
@@ -1479,33 +1484,42 @@ pub fn (mut f Fmt) sum_type_decl(node ast.SumTypeDecl) {
 	f.write_generic_types(node.generic_types)
 	f.write(' = ')
 
-	mut sum_type_names := []string{cap: node.variants.len}
-	for variant in node.variants {
-		sum_type_names << f.table.type_to_str_using_aliases(variant.typ, f.mod2alias)
+	mut variants := []Variant{cap: node.variants.len}
+	for i, variant in node.variants {
+		variants << Variant{f.table.type_to_str_using_aliases(variant.typ, f.mod2alias), i}
 		f.mark_types_import_as_used(variant.typ)
 	}
-	sum_type_names.sort()
+	variants.sort(a.name < b.name)
 
 	mut separator := ' | '
+	mut is_multiline := false
 	// if line length is too long, put each type on its own line
 	mut line_length := f.out.len - start_pos
-	for sum_type_name in sum_type_names {
+	for variant in variants {
 		// 3 = length of ' = ' or ' | '
-		line_length += 3 + sum_type_name.len
-		if line_length > fmt.max_len.last() {
+		line_length += 3 + variant.name.len
+		if line_length > fmt.max_len.last() || (variant.id != node.variants.len - 1
+			&& node.variants[variant.id].end_comments.len > 0) {
 			separator = '\n\t| '
+			is_multiline = true
 			break
 		}
 	}
 
-	for i, name in sum_type_names {
+	for i, variant in variants {
 		if i > 0 {
 			f.write(separator)
 		}
-		f.write(name)
+		f.write(variant.name)
+		if node.variants[variant.id].end_comments.len > 0 && is_multiline {
+			f.comments(node.variants[variant.id].end_comments, has_nl: false)
+		}
+	}
+	if !is_multiline {
+		f.comments(node.variants.last().end_comments,
+			has_nl: false
+		)
 	}
-
-	f.comments(node.comments, has_nl: false)
 }
 
 //=== Specific Expr methods ===//

vlib/v/fmt/tests/types_expected.vv

@@ -5,6 +5,20 @@ pub type PublicBar = Bar | Foo | FooBar
 type Uint = u16 | u32 | u64 | u8 // This should stay on the same line
 type Float = f32 | f64
 
+// Callback represents all the possible callbacks
+pub type Callback = ConnectedCallback // connected callback
+	| DisconnectedCallback // disconnected callback
+	| LoggedOffCallback // logged off callback
+	| LoggedOnCallback // logged on callback
+
+struct ConnectedCallback {}
+
+struct DisconnectedCallback {}
+
+struct LoggedOnCallback {}
+
+struct LoggedOffCallback {}
+
 // Alias type
 type MyInt = int
 

vlib/v/fmt/tests/types_input.vv

@@ -5,6 +5,17 @@ pub type PublicBar = Bar | Foo | FooBar
 type Uint = u16 | u32 | u64 | u8 // This should stay on the same line
 type Float = f32 | f64
 
+// Callback represents all the possible callbacks
+pub type Callback = ConnectedCallback 	// connected callback
+	| LoggedOnCallback // logged on callback
+	| DisconnectedCallback 	// disconnected callback
+	| LoggedOffCallback // logged off callback
+
+struct ConnectedCallback{}
+struct DisconnectedCallback{}
+struct LoggedOnCallback{}
+struct LoggedOffCallback{}
+
 // Alias type
 type MyInt = int
 

vlib/v/parser/parse_type.v

@@ -371,13 +371,15 @@ pub fn (mut p Parser) parse_sum_type_variants() []ast.TypeNode {
 	for {
 		type_start_pos := p.tok.pos()
 		typ := p.parse_type()
+		end_comments := p.eat_comments(same_line: true)
 		// TODO: needs to be its own var, otherwise TCC fails because of a known stack error
 		prev_tok := p.prev_tok
 		type_end_pos := prev_tok.pos()
 		type_pos := type_start_pos.extend(type_end_pos)
 		types << ast.TypeNode{
 			typ: typ
 			pos: type_pos
+			end_comments: end_comments
 		}
 		if p.tok.kind != .pipe {
 			break

vlib/v/parser/parser.v

@@ -4099,7 +4099,6 @@ fn (mut p Parser) type_decl() ast.TypeDecl {
 				name_pos)
 			return ast.SumTypeDecl{}
 		}
-		comments = p.eat_comments(same_line: true)
 		return ast.SumTypeDecl{
 			name: name
 			typ: typ
@@ -4109,7 +4108,6 @@ fn (mut p Parser) type_decl() ast.TypeDecl {
 			attrs: p.attrs
 			pos: decl_pos
 			name_pos: name_pos
-			comments: comments
 		}
 	}
 	// type MyType = int