all: remove inline sum types completely

vlib/v/parser/parse_type.v

@@ -409,50 +409,9 @@ fn (mut p Parser) parse_language() ast.Language {
 // parse_inline_sum_type parses the type and registers it in case the type is an anonymous sum type.
 // It also takes care of inline sum types where parse_type only parses a standalone type.
 fn (mut p Parser) parse_inline_sum_type() ast.Type {
-	if !p.pref.is_fmt {
-		p.warn(
-			'inline sum types have been deprecated and will be removed on January 1, 2023 due ' +
-			'to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead')
-	}
-	variants := p.parse_sum_type_variants()
-	if variants.len > 1 {
-		if variants.len > maximum_inline_sum_type_variants {
-			pos := variants[0].pos.extend(variants.last().pos)
-			p.warn_with_pos('an inline sum type expects a maximum of ${maximum_inline_sum_type_variants} types (${variants.len} were given)',
-				pos)
-		}
-		mut variant_names := []string{}
-		for variant in variants {
-			if variant.typ == 0 {
-				p.error_with_pos('unknown type for variant: ${variant}', variant.pos)
-				return ast.no_type
-			}
-			variant_names << p.table.sym(variant.typ).name
-		}
-		variant_names.sort()
-		// deterministic name
-		name := '_v_anon_sum_type_${variant_names.join('_')}'
-		variant_types := variants.map(it.typ)
-		prepend_mod_name := p.prepend_mod(name)
-		mut idx := p.table.find_type_idx(prepend_mod_name)
-		if idx > 0 {
-			return ast.new_type(idx)
-		}
-		idx = p.table.register_sym(ast.TypeSymbol{
-			kind:  .sum_type
-			name:  prepend_mod_name
-			cname: util.no_dots(prepend_mod_name)
-			mod:   p.mod
-			info:  ast.SumType{
-				is_anon:  true
-				variants: variant_types
-			}
-		})
-		return ast.new_type(idx)
-	} else if variants.len == 1 {
-		return variants[0].typ
-	}
-	return ast.no_type
+	p.error('inline sum types have been deprecated and will be removed on January 1, 2023 due ' +
+		'to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead')
+	return ast.void_type
 }
 
 // parse_sum_type_variants parses several types separated with a pipe and returns them as a list with at least one node.
@@ -589,9 +548,6 @@ fn (mut p Parser) parse_type() ast.Type {
 				p.error_with_pos('missing concrete type on generic type', option_pos.extend(p.prev_tok.pos()))
 			}
 		}
-		if is_option && sym.info is ast.SumType && sym.info.is_anon {
-			p.error_with_pos('an inline sum type cannot be an Option', option_pos.extend(p.prev_tok.pos()))
-		}
 
 		if is_option && sym.info is ast.Alias && sym.info.parent_type.has_flag(.option) {
 			alias_type_str := p.table.type_to_str(typ)

vlib/v/parser/tests/anon_sum_type_interface.out

@@ -1,4 +1,4 @@
-vlib/v/parser/tests/anon_sum_type_interface.vv:2:6: warning: inline sum types have been deprecated and will be removed on January 1, 2023 due to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead
+vlib/v/parser/tests/anon_sum_type_interface.vv:2:6: error: inline sum types have been deprecated and will be removed on January 1, 2023 due to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead
     1 | interface Foo {
     2 |     bar string|int
       |         ~~~~~~

vlib/v/parser/tests/anon_sum_type_struct.out

@@ -1,4 +1,4 @@
-vlib/v/parser/tests/anon_sum_type_struct.vv:2:6: warning: inline sum types have been deprecated and will be removed on January 1, 2023 due to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead
+vlib/v/parser/tests/anon_sum_type_struct.vv:2:6: error: inline sum types have been deprecated and will be removed on January 1, 2023 due to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead
     1 | struct Foo {
     2 |     bar string|int
       |         ~~~~~~

vlib/v/parser/tests/inline_sum_type_option_err.out

@@ -1,10 +1,5 @@
-vlib/v/parser/tests/inline_sum_type_option_err.vv:1:11: warning: inline sum types have been deprecated and will be removed on January 1, 2023 due to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead
+vlib/v/parser/tests/inline_sum_type_option_err.vv:1:11: error: inline sum types have been deprecated and will be removed on January 1, 2023 due to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead
     1 | fn foo() ?string | int {
       |           ~~~~~~
     2 |     return 0
     3 | }
-vlib/v/parser/tests/inline_sum_type_option_err.vv:1:10: error: an inline sum type cannot be an Option
-    1 | fn foo() ?string | int {
-      |          ~~~~~~~~~~~~~
-    2 |     return 0
-    3 | }

vlib/v/parser/tests/inline_sum_type_return_type_too_many_variants.out

@@ -1,42 +1,7 @@
-vlib/v/parser/tests/inline_sum_type_return_type_too_many_variants.vv:4:6: warning: inline sum types have been deprecated and will be removed on January 1, 2023 due to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead
-    2 | 
+vlib/v/parser/tests/inline_sum_type_return_type_too_many_variants.vv:4:6: error: inline sum types have been deprecated and will be removed on January 1, 2023 due to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead
+    2 |
     3 | struct Foo {
     4 |     bar int|string|token.Pos|bool|u32
       |         ~~~
     5 | }
     6 |
-vlib/v/parser/tests/inline_sum_type_return_type_too_many_variants.vv:4:6: warning: an inline sum type expects a maximum of 3 types (5 were given)
-    2 | 
-    3 | struct Foo {
-    4 |     bar int|string|token.Pos|bool|u32
-      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-    5 | }
-    6 |
-vlib/v/parser/tests/inline_sum_type_return_type_too_many_variants.vv:7:12: warning: inline sum types have been deprecated and will be removed on January 1, 2023 due to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead
-    5 | }
-    6 | 
-    7 | fn foo(arg int|string|token.Pos|bool|u32) int|string|token.Pos|bool|u32 {
-      |            ~~~
-    8 |     return 1
-    9 | }
-vlib/v/parser/tests/inline_sum_type_return_type_too_many_variants.vv:7:12: warning: an inline sum type expects a maximum of 3 types (5 were given)
-    5 | }
-    6 | 
-    7 | fn foo(arg int|string|token.Pos|bool|u32) int|string|token.Pos|bool|u32 {
-      |            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-    8 |     return 1
-    9 | }
-vlib/v/parser/tests/inline_sum_type_return_type_too_many_variants.vv:7:43: warning: inline sum types have been deprecated and will be removed on January 1, 2023 due to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead
-    5 | }
-    6 | 
-    7 | fn foo(arg int|string|token.Pos|bool|u32) int|string|token.Pos|bool|u32 {
-      |                                           ~~~
-    8 |     return 1
-    9 | }
-vlib/v/parser/tests/inline_sum_type_return_type_too_many_variants.vv:7:43: warning: an inline sum type expects a maximum of 3 types (5 were given)
-    5 | }
-    6 | 
-    7 | fn foo(arg int|string|token.Pos|bool|u32) int|string|token.Pos|bool|u32 {
-      |                                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-    8 |     return 1
-    9 | }

vlib/v/parser/tests/option_sum_type_return_err.out

@@ -1,10 +1,5 @@
-vlib/v/parser/tests/option_sum_type_return_err.vv:1:22: warning: inline sum types have been deprecated and will be removed on January 1, 2023 due to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead
+vlib/v/parser/tests/option_sum_type_return_err.vv:1:22: error: inline sum types have been deprecated and will be removed on January 1, 2023 due to complicating the language and the compiler too much; define named sum types with `type Foo = Bar | Baz` instead
     1 | fn option_sumtype() ?string | int {
       |                      ~~~~~~
     2 |     return 0
     3 | }
-vlib/v/parser/tests/option_sum_type_return_err.vv:1:21: error: an inline sum type cannot be an Option
-    1 | fn option_sumtype() ?string | int {
-      |                     ~~~~~~~~~~~~~
-    2 |     return 0
-    3 | }