From 9b4dec7b98878d820ce1d4672e25d990afc31a2b Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@vlang.io>
Date: Tue, 5 Jul 2022 23:17:00 +0300
Subject: [PATCH] parser: anonymous structs (part 1)

---
 vlib/v/markused/walker.v   |  2 +-
 vlib/v/parser/expr.v       |  4 +++-
 vlib/v/parser/parse_type.v |  7 +++++++
 vlib/v/parser/parser.v     |  6 +++---
 vlib/v/parser/struct.v     | 10 +++++-----
 5 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/vlib/v/markused/walker.v b/vlib/v/markused/walker.v
index 110e8916d2..40207c6132 100644
--- a/vlib/v/markused/walker.v
+++ b/vlib/v/markused/walker.v
@@ -353,7 +353,7 @@ fn (mut w Walker) expr(node_ ast.Expr) {
 			}
 		}
 		ast.None {}
-		ast.Nil{}
+		ast.Nil {}
 		ast.ParExpr {
 			w.expr(node.expr)
 		}
diff --git a/vlib/v/parser/expr.v b/vlib/v/parser/expr.v
index 019d2baa22..c4aaa0b2ff 100644
--- a/vlib/v/parser/expr.v
+++ b/vlib/v/parser/expr.v
@@ -133,7 +133,9 @@ pub fn (mut p Parser) check_expr(precedence int) ?ast.Expr {
 			node = p.select_expr()
 		}
 		.key_nil {
-			node = ast.Nil{pos:p.tok.pos()}
+			node = ast.Nil{
+				pos: p.tok.pos()
+			}
 			p.next()
 		}
 		.number {
diff --git a/vlib/v/parser/parse_type.v b/vlib/v/parser/parse_type.v
index fb62be59ef..6d2860ae0a 100644
--- a/vlib/v/parser/parse_type.v
+++ b/vlib/v/parser/parse_type.v
@@ -423,6 +423,13 @@ pub fn (mut p Parser) parse_type() ast.Type {
 		nr_muls++
 		p.next()
 	}
+	// Anon structs
+	if p.tok.kind == .key_struct {
+		p.struct_decl(true)
+		p.next()
+		return p.table.find_type_idx('anon_struct') // TODO
+	}
+
 	language := p.parse_language()
 	mut typ := ast.void_type
 	is_array := p.tok.kind == .lsbr
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index f7122bb45f..ee4aa7d362 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -620,7 +620,7 @@ pub fn (mut p Parser) top_stmt() ast.Stmt {
 						return p.fn_decl()
 					}
 					.key_struct, .key_union {
-						return p.struct_decl()
+						return p.struct_decl(false)
 					}
 					.key_interface {
 						return p.interface_decl()
@@ -662,7 +662,7 @@ pub fn (mut p Parser) top_stmt() ast.Stmt {
 				return p.fn_decl()
 			}
 			.key_struct {
-				return p.struct_decl()
+				return p.struct_decl(false)
 			}
 			.dollar {
 				if p.peek_tok.kind == .eof {
@@ -689,7 +689,7 @@ pub fn (mut p Parser) top_stmt() ast.Stmt {
 				return p.enum_decl()
 			}
 			.key_union {
-				return p.struct_decl()
+				return p.struct_decl(false)
 			}
 			.comment {
 				return p.comment_stmt()
diff --git a/vlib/v/parser/struct.v b/vlib/v/parser/struct.v
index affd50a570..83ceafb3ff 100644
--- a/vlib/v/parser/struct.v
+++ b/vlib/v/parser/struct.v
@@ -7,7 +7,7 @@ import v.ast
 import v.token
 import v.util
 
-fn (mut p Parser) struct_decl() ast.StructDecl {
+fn (mut p Parser) struct_decl(is_anon bool) ast.StructDecl {
 	p.top_level_statement_start()
 	// save attributes, they will be changed later in fields
 	attrs := p.attrs
@@ -39,7 +39,7 @@ fn (mut p Parser) struct_decl() ast.StructDecl {
 	if p.disallow_declarations_in_script_mode() {
 		return ast.StructDecl{}
 	}
-	mut name := p.check_name()
+	mut name := if is_anon { '' } else { p.check_name()}
 	if name.len == 1 && name[0].is_capital() {
 		p.error_with_pos('single letter capital names are reserved for generic template types.',
 			name_pos)
@@ -322,7 +322,7 @@ fn (mut p Parser) struct_decl() ast.StructDecl {
 		p.check(.rcbr)
 	}
 	is_minify := attrs.contains('minify')
-	mut t := ast.TypeSymbol{
+	mut sym := ast.TypeSymbol{
 		kind: .struct_
 		language: language
 		name: name
@@ -341,11 +341,11 @@ fn (mut p Parser) struct_decl() ast.StructDecl {
 		}
 		is_pub: is_pub
 	}
-	if p.table.has_deep_child_no_ref(&t, name) {
+	if p.table.has_deep_child_no_ref(&sym, name) {
 		p.error_with_pos('invalid recursive struct `$orig_name`', name_pos)
 		return ast.StructDecl{}
 	}
-	mut ret := p.table.register_sym(t)
+	mut ret := p.table.register_sym(sym)
 	// allow duplicate c struct declarations
 	if ret == -1 && language != .c {
 		p.error_with_pos('cannot register struct `$name`, another type with this name exists',