all: unsafe nil

vlib/v/ast/ast.v

@@ -42,6 +42,7 @@ pub type Expr = AnonFn
 	| LockExpr
 	| MapInit
 	| MatchExpr
+	| Nil
 	| NodeError
 	| None
 	| OffsetOf
@@ -240,6 +241,11 @@ pub:
 	pos token.Pos
 }
 
+pub struct Nil {
+pub:
+	pos token.Pos
+}
+
 pub enum GenericKindField {
 	unknown
 	name
@@ -1774,7 +1780,7 @@ pub fn (expr Expr) pos() token.Pos {
 		EnumVal, DumpExpr, FloatLiteral, GoExpr, Ident, IfExpr, IntegerLiteral, IsRefType, Likely,
 		LockExpr, MapInit, MatchExpr, None, OffsetOf, OrExpr, ParExpr, PostfixExpr, PrefixExpr,
 		RangeExpr, SelectExpr, SelectorExpr, SizeOf, SqlExpr, StringInterLiteral, StringLiteral,
-		StructInit, TypeNode, TypeOf, UnsafeExpr, ComptimeType {
+		StructInit, TypeNode, TypeOf, UnsafeExpr, ComptimeType, Nil {
 			return expr.pos
 		}
 		IndexExpr {

vlib/v/ast/str.v

@@ -387,6 +387,9 @@ pub fn (x Expr) str() string {
 			}
 			return 'map{ ${pairs.join(' ')} }'
 		}
+		Nil {
+			return 'nil'
+		}
 		ParExpr {
 			return '($x.expr)'
 		}

vlib/v/ast/types.v

@@ -442,13 +442,14 @@ pub const (
 	int_literal_type_idx   = 27
 	thread_type_idx        = 28
 	error_type_idx         = 29
+	nil_type_idx           = 30
 		// u8_type_idx            = 30
 )
 
 // Note: builtin_type_names must be in the same order as the idx consts above
 pub const builtin_type_names = ['void', 'voidptr', 'byteptr', 'charptr', 'i8', 'i16', 'int', 'i64',
 	'isize', 'u8', 'u16', 'u32', 'u64', 'usize', 'f32', 'f64', 'char', 'bool', 'none', 'string',
-	'rune', 'array', 'map', 'chan', 'any', 'float_literal', 'int_literal', 'thread', 'Error', 'u8']
+	'rune', 'array', 'map', 'chan', 'any', 'float_literal', 'int_literal', 'thread', 'Error', 'nil']
 
 pub const builtin_type_names_matcher = build_builtin_type_names_matcher()
 
@@ -509,6 +510,7 @@ pub const (
 	byteptr_types      = new_byteptr_types()
 	voidptr_types      = new_voidptr_types()
 	cptr_types         = merge_types(voidptr_types, byteptr_types, charptr_types)
+	nil_type           = new_type(nil_type_idx)
 )
 
 fn new_charptr_types() []Type {
@@ -809,7 +811,7 @@ pub fn (mut t Table) register_builtin_type_symbols() {
 		}
 	)
 	t.register_sym(kind: .interface_, name: 'IError', cname: 'IError', mod: 'builtin')
-	t.register_sym(kind: .u8, name: 'zu8', cname: 'zu8', mod: 'builtin')
+	t.register_sym(kind: .voidptr, name: 'nil', cname: 'nil', mod: 'builtin')
 }
 
 [inline]

vlib/v/checker/checker.v

@@ -2213,6 +2213,12 @@ pub fn (mut c Checker) expr(node_ ast.Expr) ast.Type {
 		ast.MatchExpr {
 			return c.match_expr(mut node)
 		}
+		ast.Nil {
+			if !c.inside_unsafe {
+				c.error('`nil` is only allowed in `unsafe` code', node.pos)
+			}
+			return ast.nil_type
+		}
 		ast.PostfixExpr {
 			return c.postfix_expr(mut node)
 		}

vlib/v/fmt/fmt.v

@@ -622,6 +622,9 @@ pub fn (mut f Fmt) expr(node_ ast.Expr) {
 		ast.None {
 			f.write('none')
 		}
+		ast.Nil {
+			f.write('nil')
+		}
 		ast.OffsetOf {
 			f.offset_of(node)
 		}

vlib/v/gen/c/cgen.v

@@ -3020,6 +3020,9 @@ fn (mut g Gen) expr(node_ ast.Expr) {
 			g.match_expr(node)
 		}
 		ast.NodeError {}
+		ast.Nil {
+			g.write('((void*)0)')
+		}
 		ast.None {
 			g.write('_const_none__')
 		}

vlib/v/markused/walker.v

@@ -353,6 +353,7 @@ fn (mut w Walker) expr(node_ ast.Expr) {
 			}
 		}
 		ast.None {}
+		ast.Nil{}
 		ast.ParExpr {
 			w.expr(node.expr)
 		}

vlib/v/parser/expr.v

@@ -132,6 +132,10 @@ pub fn (mut p Parser) check_expr(precedence int) ?ast.Expr {
 		.key_select {
 			node = p.select_expr()
 		}
+		.key_nil {
+			node = ast.Nil{pos:p.tok.pos()}
+			p.next()
+		}
 		.number {
 			node = p.parse_number_literal()
 		}

vlib/v/token/token.v

@@ -108,6 +108,7 @@ pub enum Kind {
 	key_match
 	key_module
 	key_mut
+	key_nil
 	key_shared
 	key_lock
 	key_rlock
@@ -313,6 +314,7 @@ fn build_token_str() []string {
 	s[Kind.key_match] = 'match'
 	s[Kind.key_select] = 'select'
 	s[Kind.key_none] = 'none'
+	s[Kind.key_nil] = 'nil'
 	s[Kind.key_offsetof] = '__offsetof'
 	s[Kind.key_is] = 'is'
 	// The following kinds are not for tokens returned by the V scanner.
@@ -617,6 +619,7 @@ pub fn kind_to_string(k Kind) string {
 		.key_unsafe { 'key_unsafe' }
 		.keyword_end { 'keyword_end' }
 		._end_ { '_end_' }
+		.key_nil { 'key_nil' }
 	}
 }