all: initial implementation of compile-time types (#13549)

vlib/v/ast/ast.v

@@ -24,6 +24,7 @@ pub type Expr = AnonFn
 	| Comment
 	| ComptimeCall
 	| ComptimeSelector
+	| ComptimeType
 	| ConcatExpr
 	| DumpExpr
 	| EmptyExpr
@@ -114,6 +115,36 @@ pub:
 	pos token.Pos
 }
 
+pub enum ComptimeTypeKind {
+	map_
+	int
+	float
+	struct_
+	iface
+	array
+	sum_type
+	enum_
+}
+
+pub struct ComptimeType {
+pub:
+	kind ComptimeTypeKind
+	pos  token.Pos
+}
+
+pub fn (cty ComptimeType) str() string {
+	return match cty.kind {
+		.map_ { '\$Map' }
+		.int { '\$Int' }
+		.float { '\$Float' }
+		.struct_ { '\$Struct' }
+		.iface { '\$Interface' }
+		.array { '\$Array' }
+		.sum_type { '\$Sumtype' }
+		.enum_ { '\$Enum' }
+	}
+}
+
 pub struct EmptyExpr {
 	x int
 }
@@ -1683,7 +1714,7 @@ 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 {
+		StructInit, TypeNode, TypeOf, UnsafeExpr, ComptimeType {
 			return expr.pos
 		}
 		IndexExpr {

vlib/v/ast/str.v

@@ -261,6 +261,9 @@ pub fn (x Expr) str() string {
 		AnonFn {
 			return 'anon_fn'
 		}
+		ComptimeType {
+			return x.str()
+		}
 		DumpExpr {
 			return 'dump($x.expr.str())'
 		}

vlib/v/ast/table.v

@@ -2044,3 +2044,49 @@ pub fn (mut t Table) generic_insts_to_concrete() {
 		}
 	}
 }
+
+pub fn (t &Table) is_comptime_type(x Type, y ComptimeType) bool {
+	x_kind := t.type_kind(x)
+	match y.kind {
+		.map_ {
+			return x_kind == .map
+		}
+		.int {
+			return x_kind in [
+				.i8,
+				.i16,
+				.int,
+				.i64,
+				.byte,
+				.u8,
+				.u16,
+				.u32,
+				.u64,
+				.usize,
+				.int_literal,
+			]
+		}
+		.float {
+			return x_kind in [
+				.f32,
+				.f64,
+				.float_literal,
+			]
+		}
+		.struct_ {
+			return x_kind == .struct_
+		}
+		.iface {
+			return x_kind == .interface_
+		}
+		.array {
+			return x_kind in [.array, .array_fixed]
+		}
+		.sum_type {
+			return x_kind == .sum_type
+		}
+		.enum_ {
+			return x_kind == .enum_
+		}
+	}
+}

vlib/v/checker/checker.v

@@ -2384,6 +2384,9 @@ pub fn (mut c Checker) expr(node ast.Expr) ast.Type {
 	}
 	match mut node {
 		ast.NodeError {}
+		ast.ComptimeType {
+			c.error('incorrect use of compile-time type', node.pos)
+		}
 		ast.EmptyExpr {
 			c.error('checker.expr(): unhandled EmptyExpr', token.Pos{})
 		}

vlib/v/checker/comptime.v

@@ -468,6 +468,10 @@ fn (mut c Checker) comptime_if_branch(cond ast.Expr, pos token.Pos) bool {
 							// c.error('`$sym.name` is not an interface', cond.right.pos())
 						}
 						return false
+					} else if cond.left is ast.TypeNode && cond.right is ast.ComptimeType {
+						left := cond.left as ast.TypeNode
+						checked_type := c.unwrap_generic(left.typ)
+						return c.table.is_comptime_type(checked_type, cond.right)
 					} else if cond.left in [ast.SelectorExpr, ast.TypeNode] {
 						// `$if method.@type is string`
 						c.expr(cond.left)

vlib/v/checker/if.v

@@ -52,32 +52,39 @@ pub fn (mut c Checker) if_expr(mut node ast.IfExpr) ast.Type {
 			mut comptime_field_name := ''
 			if mut branch.cond is ast.InfixExpr {
 				if branch.cond.op == .key_is {
-					if branch.cond.right !is ast.TypeNode {
+					if branch.cond.right !is ast.TypeNode && branch.cond.right !is ast.ComptimeType {
 						c.error('invalid `\$if` condition: expected a type', branch.cond.right.pos())
 						return 0
 					}
-					got_type := c.unwrap_generic((branch.cond.right as ast.TypeNode).typ)
-					sym := c.table.sym(got_type)
-					if sym.kind == .placeholder || got_type.has_flag(.generic) {
-						c.error('unknown type `$sym.name`', branch.cond.right.pos())
-					}
 					left := branch.cond.left
-					if left is ast.SelectorExpr {
-						comptime_field_name = left.expr.str()
-						c.comptime_fields_type[comptime_field_name] = got_type
+					if branch.cond.right is ast.ComptimeType && left is ast.TypeNode {
 						is_comptime_type_is_expr = true
-					} else if branch.cond.right is ast.TypeNode && left is ast.TypeNode
-						&& sym.kind == .interface_ {
-						is_comptime_type_is_expr = true
-						// is interface
 						checked_type := c.unwrap_generic(left.typ)
-						should_skip = !c.table.does_type_implement_interface(checked_type,
-							got_type)
-					} else if left is ast.TypeNode {
-						is_comptime_type_is_expr = true
-						left_type := c.unwrap_generic(left.typ)
-						if left_type != got_type {
-							should_skip = true
+						should_skip = !c.table.is_comptime_type(checked_type, branch.cond.right as ast.ComptimeType)
+					} else {
+						got_type := c.unwrap_generic((branch.cond.right as ast.TypeNode).typ)
+						sym := c.table.sym(got_type)
+						if sym.kind == .placeholder || got_type.has_flag(.generic) {
+							c.error('unknown type `$sym.name`', branch.cond.right.pos())
+						}
+
+						if left is ast.SelectorExpr {
+							comptime_field_name = left.expr.str()
+							c.comptime_fields_type[comptime_field_name] = got_type
+							is_comptime_type_is_expr = true
+						} else if branch.cond.right is ast.TypeNode && left is ast.TypeNode
+							&& sym.kind == .interface_ {
+							is_comptime_type_is_expr = true
+							// is interface
+							checked_type := c.unwrap_generic(left.typ)
+							should_skip = !c.table.does_type_implement_interface(checked_type,
+								got_type)
+						} else if left is ast.TypeNode {
+							is_comptime_type_is_expr = true
+							left_type := c.unwrap_generic(left.typ)
+							if left_type != got_type {
+								should_skip = true
+							}
 						}
 					}
 				}

vlib/v/fmt/fmt.v

@@ -660,6 +660,18 @@ pub fn (mut f Fmt) expr(node ast.Expr) {
 		ast.UnsafeExpr {
 			f.unsafe_expr(node)
 		}
+		ast.ComptimeType {
+			match node.kind {
+				.array { f.write('\$Array') }
+				.struct_ { f.write('\$Struct') }
+				.iface { f.write('\$Interface') }
+				.map_ { f.write('\$Map') }
+				.int { f.write('\$Int') }
+				.float { f.write('\$Float') }
+				.sum_type { f.write('\$Sumtype') }
+				.enum_ { f.write('\$Enum') }
+			}
+		}
 	}
 }
 

vlib/v/gen/c/cgen.v

@@ -2740,6 +2740,9 @@ fn (mut g Gen) expr(node ast.Expr) {
 	}
 	// NB: please keep the type names in the match here in alphabetical order:
 	match mut node {
+		ast.ComptimeType {
+			g.error('g.expr(): Unhandled ComptimeType', node.pos)
+		}
 		ast.EmptyExpr {
 			g.error('g.expr(): unhandled EmptyExpr', token.Pos{})
 		}

vlib/v/gen/c/comptime.v

@@ -337,6 +337,25 @@ fn (mut g Gen) comptime_if_cond(cond ast.Expr, pkg_exist bool) bool {
 				.key_is, .not_is {
 					left := cond.left
 					mut name := ''
+					if left is ast.TypeNode && cond.right is ast.ComptimeType {
+						checked_type := g.unwrap_generic(left.typ)
+						is_true := g.table.is_comptime_type(checked_type, cond.right)
+						if cond.op == .key_is {
+							if is_true {
+								g.write('1')
+							} else {
+								g.write('0')
+							}
+							return is_true
+						} else {
+							if is_true {
+								g.write('0')
+							} else {
+								g.write('1')
+							}
+							return !is_true
+						}
+					}
 					mut exp_type := ast.Type(0)
 					got_type := (cond.right as ast.TypeNode).typ
 					// Handle `$if x is Interface {`

vlib/v/gen/js/js.v

@@ -856,6 +856,9 @@ fn (mut g JsGen) stmt(node ast.Stmt) {
 fn (mut g JsGen) expr(node ast.Expr) {
 	// NB: please keep the type names in the match here in alphabetical order:
 	match mut node {
+		ast.ComptimeType {
+			verror('not yet implemented')
+		}
 		ast.EmptyExpr {}
 		ast.AnonFn {
 			g.gen_anon_fn(mut node)

vlib/v/markused/walker.v

@@ -221,6 +221,7 @@ fn (mut w Walker) expr(node ast.Expr) {
 			// TODO make sure this doesn't happen
 			// panic('Walker: EmptyExpr')
 		}
+		ast.ComptimeType {}
 		ast.AnonFn {
 			w.fn_decl(mut node.decl)
 		}

vlib/v/parser/comptime.v

@@ -10,8 +10,50 @@ import v.token
 
 const (
 	supported_comptime_calls = ['html', 'tmpl', 'env', 'embed_file', 'pkgconfig']
+	comptime_types           = ['Map', 'Array', 'Int', 'Float', 'Struct', 'Interface', 'Enum',
+		'Sumtype']
 )
 
+pub fn (mut p Parser) parse_comptime_type() ast.ComptimeType {
+	mut node := ast.ComptimeType{ast.ComptimeTypeKind.map_, p.tok.pos()}
+
+	p.check(.dollar)
+	name := p.check_name()
+	if name !in parser.comptime_types {
+		p.error('unsupported compile-time type `$name`: only $parser.comptime_types are supported')
+	}
+	mut cty := ast.ComptimeTypeKind.map_
+	match name {
+		'Map' {
+			cty = .map_
+		}
+		'Struct' {
+			cty = .struct_
+		}
+		'Interface' {
+			cty = .iface
+		}
+		'Int' {
+			cty = .int
+		}
+		'Float' {
+			cty = .float
+		}
+		'Array' {
+			cty = .array
+		}
+		'Enum' {
+			cty = .enum_
+		}
+		'Sumtype' {
+			cty = .sum_type
+		}
+		else {}
+	}
+	node = ast.ComptimeType{cty, node.pos}
+	return node
+}
+
 // // #include, #flag, #v
 fn (mut p Parser) hash() ast.HashStmt {
 	pos := p.tok.pos()

vlib/v/parser/expr.v

@@ -78,7 +78,11 @@ pub fn (mut p Parser) check_expr(precedence int) ?ast.Expr {
 		.dollar {
 			match p.peek_tok.kind {
 				.name {
-					node = p.comptime_call()
+					if p.peek_tok.lit in comptime_types {
+						node = p.parse_comptime_type()
+					} else {
+						node = p.comptime_call()
+					}
 					p.is_stmt_ident = is_stmt_ident
 				}
 				.key_if {
@@ -490,6 +494,7 @@ fn (mut p Parser) infix_expr(left ast.Expr) ast.Expr {
 	if is_key_in {
 		p.inside_in_array = true
 	}
+
 	right = p.expr(precedence)
 	if is_key_in {
 		p.inside_in_array = false

vlib/v/parser/parser.v

@@ -2105,6 +2105,11 @@ pub fn (mut p Parser) name_expr() ast.Expr {
 	prev_tok_kind := p.prev_tok.kind
 	mut node := ast.empty_expr()
 	if p.expecting_type {
+		if p.tok.kind == .dollar {
+			node = p.parse_comptime_type()
+			p.expecting_type = false
+			return node
+		}
 		p.expecting_type = false
 		// get type position before moving to next
 		type_pos := p.tok.pos()

vlib/v/tests/comptime_kinds_test.v

@@ -0,0 +1,84 @@
+fn assert_map<T>() {
+	$if T is $Map {
+		assert true
+	} $else {
+		assert false
+	}
+}
+
+fn assert_array<T>() {
+	$if T is $Array {
+		assert true
+	} $else {
+		assert false
+	}
+}
+
+fn assert_struct<T>() {
+	$if T is $Struct {
+		assert true
+	} $else {
+		assert false
+	}
+}
+
+fn assert_not_struct<T>() {
+	$if T is $Struct {
+		assert false
+	} $else {
+		assert true
+	}
+}
+
+fn assert_not_map<T>() {
+	$if T is $Map {
+		assert false
+	} $else {
+		assert true
+	}
+}
+
+fn assert_not_array<T>() {
+	$if T is $Array {
+		assert false
+	} $else {
+		assert true
+	}
+}
+
+struct Abc {}
+
+struct Bc {}
+
+struct Cd {}
+
+fn test_kind_map() {
+	assert_map<map[int]int>()
+	assert_map<map[string]int>()
+	assert_map<map[i64]i8>()
+
+	assert_not_map<Abc>()
+	assert_not_map<int>()
+	assert_not_map<[]int>()
+}
+
+fn test_kind_array() {
+	assert_array<[]int>()
+	assert_array<[]f32>()
+	assert_array<[]string>()
+
+	assert_not_array<Abc>()
+	assert_not_array<string>()
+	assert_not_array<int>()
+	assert_not_array<map[int]int>()
+}
+
+fn test_kind_struct() {
+	assert_struct<Abc>()
+	assert_struct<Bc>()
+	assert_struct<Cd>()
+
+	assert_not_struct<int>()
+	assert_not_struct<[]int>()
+	assert_not_struct<map[int]int>()
+}