From b290efa394a931b962d46ecd48152f4cdf6ce2fa Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Thu, 19 Mar 2020 12:15:39 +0100
Subject: [PATCH] ast: TypeOf

---
 vlib/v/ast/ast.v         |  7 ++++++-
 vlib/v/checker/checker.v |  3 +++
 vlib/v/gen/cgen.v        |  3 +++
 vlib/v/gen/jsgen.v       | 12 +++++++-----
 vlib/v/parser/parser.v   |  9 +++++++++
 vlib/v/token/token.v     |  4 ++--
 6 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index 3366f593bb..d1df59a823 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -14,7 +14,7 @@ pub type Expr = InfixExpr | IfExpr | StringLiteral | IntegerLiteral | CharLitera
 FloatLiteral | Ident | CallExpr | BoolLiteral | StructInit | ArrayInit | SelectorExpr | PostfixExpr | 	
 AssignExpr | PrefixExpr | MethodCallExpr | IndexExpr | RangeExpr | MatchExpr | 	
 CastExpr | EnumVal | Assoc | SizeOf | None | MapInit | IfGuardExpr | ParExpr | OrExpr | 	
-ConcatExpr | Type | AsCast
+ConcatExpr | Type | AsCast | TypeOf
 
 pub type Stmt = GlobalDecl | FnDecl | Return | Module | Import | ExprStmt | 	
 ForStmt | StructDecl | ForCStmt | ForInStmt | CompIf | ConstDecl | Attr | BranchStmt | 	
@@ -608,6 +608,11 @@ pub:
 	type_name string
 }
 
+pub struct TypeOf {
+pub:
+	expr Expr
+}
+
 pub struct LineComment {
 pub:
 	text string
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 3f9acd3bbb..737843b129 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -741,6 +741,9 @@ pub fn (c mut Checker) expr(node ast.Expr) table.Type {
 		ast.Type {
 			return it.typ
 		}
+		ast.TypeOf {
+			return table.string_type
+		}
 		/*
 		ast.UnaryExpr {
 			c.expr(it.left)
diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index c7429fe425..d4561c5ca4 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -887,6 +887,9 @@ fn (g mut Gen) expr(node ast.Expr) {
 			g.write('_type_idx_')
 			g.write(g.typ(it.typ))
 		}
+		ast.TypeOf {
+			g.write('tos3("TYPEOF_TODO")')
+		}
 		else {
 			// #printf("node=%d\n", node.typ);
 			println(term.red('cgen.expr(): bad node ' + typeof(node)))
diff --git a/vlib/v/gen/jsgen.v b/vlib/v/gen/jsgen.v
index 795a51afb8..fc3ea73394 100644
--- a/vlib/v/gen/jsgen.v
+++ b/vlib/v/gen/jsgen.v
@@ -58,11 +58,10 @@ fn (g mut JsGen) stmt(node ast.Stmt) {
 			g.writeln(';')
 		}
 		ast.AssignStmt {
-			if it.left.len > it.right.len {
-				// TODO: multi return
-			}
+			if it.left.len > it.right.len {}
+			// TODO: multi return
 			else {
-				for i,ident in it.left {
+				for i, ident in it.left {
 					var_info := ident.var_info()
 					var_type_sym := g.table.get_type_symbol(var_info.typ)
 					val := it.right[i]
@@ -90,6 +89,8 @@ fn (g mut JsGen) stmt(node ast.Stmt) {
 		}
 		ast.ExprStmt {
 			g.expr(it.expr)
+		}
+		/*
 			match it.expr {
 				// no ; after an if expression
 				ast.IfExpr {}
@@ -97,7 +98,8 @@ fn (g mut JsGen) stmt(node ast.Stmt) {
 					g.writeln(';')
 				}
 	}
-		}
+	*/
+
 		else {
 			verror('jsgen.stmt(): bad node')
 		}
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index 5b7cb6f08a..2b4a0f3905 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -765,6 +765,15 @@ pub fn (p mut Parser) expr(precedence int) ast.Expr {
 				
 			}
 		}
+		.key_typeof {
+			p.next()
+			p.check(.lpar)
+			expr := p.expr(0)
+			p.check(.rpar)
+			node = ast.TypeOf{
+				expr: expr
+			}
+		}
 		// Map `{"age": 20}` or `{ x | foo:bar, a:10 }`
 		.lcbr {
 			p.next()
diff --git a/vlib/v/token/token.v b/vlib/v/token/token.v
index 4aaf99a2fb..a6de64dda0 100644
--- a/vlib/v/token/token.v
+++ b/vlib/v/token/token.v
@@ -114,7 +114,7 @@ pub enum Kind {
 	key_switch
 	key_true
 	key_type
-	// typeof
+	key_typeof
 	key_orelse
 	key_union
 	key_pub
@@ -229,7 +229,7 @@ fn build_token_str() []string {
 	s[Kind.key_import] = 'import'
 	s[Kind.key_embed] = 'embed'
 	s[Kind.key_unsafe] = 'unsafe'
-	// Kinds[key_typeof] = 'typeof'
+	s[Kind.key_typeof] = 'typeof'
 	s[Kind.key_enum] = 'enum'
 	s[Kind.key_interface] = 'interface'
 	s[Kind.key_pub] = 'pub'