From 831be437408f732bb634e56d2013dbfdd412e086 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Sat, 28 Mar 2020 14:38:16 +0100
Subject: [PATCH] checker: check ! operator

---
 vlib/v/ast/ast.v         | 19 ++++---------------
 vlib/v/checker/checker.v |  3 +++
 vlib/v/parser/parser.v   | 17 ++++++++++-------
 3 files changed, 17 insertions(+), 22 deletions(-)

diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index c868dc599f..b447463116 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -319,18 +319,6 @@ mut:
 	right_type table.Type
 }
 
-/*
-// renamed to PrefixExpr
-pub struct UnaryExpr {
-pub:
-// tok_kind token.Kind
-// op    BinaryOp
-	op   token.Kind
-	left Expr
-}
-*/
-
-
 pub struct PostfixExpr {
 pub:
 	op   token.Kind
@@ -342,6 +330,7 @@ pub struct PrefixExpr {
 pub:
 	op    token.Kind
 	right Expr
+	pos   token.Position
 }
 
 pub struct IndexExpr {
@@ -528,9 +517,9 @@ pub struct DeferStmt {
 pub:
 	stmts []Stmt
 mut:
-	// TODO: handle this differently
-	// v1 excludes non current os ifdefs so
-	// the defer's never get added in the first place
+// TODO: handle this differently
+// v1 excludes non current os ifdefs so
+// the defer's never get added in the first place
 	ifdef string
 }
 
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index be56d462e5..e7f79c2675 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -746,6 +746,9 @@ pub fn (c mut Checker) expr(node ast.Expr) table.Type {
 			if it.op == .mul && table.type_is_ptr(right_type) {
 				return table.type_deref(right_type)
 			}
+			if it.op == .not && right_type != table.bool_type_idx {
+				c.error('! operator can only be used with bool types', it.pos)
+			}
 			return right_type
 		}
 		ast.None {
diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index 9bb7362c68..62bef84851 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -52,7 +52,7 @@ pub fn parse_stmt(text string, table &table.Table, scope &ast.Scope) ast.Stmt {
 		pref: &pref.Preferences{}
 		scope: scope
 		// scope: &ast.Scope{start_pos: 0, parent: 0}
-
+		
 	}
 	p.init_parse_fns()
 	p.read_first_token()
@@ -70,13 +70,14 @@ pub fn parse_file(path string, table &table.Table, comments_mode scanner.Comment
 		scanner: scanner.new_scanner_file(path, comments_mode)
 		table: table
 		file_name: path
-		pref: pref //&pref.Preferences{}
+		pref: pref // &pref.Preferences{}
+		
 		scope: &ast.Scope{
 			start_pos: 0
 			parent: 0
 		}
 		// comments_mode: comments_mode
-
+		
 	}
 	p.read_first_token()
 	// p.scope = &ast.Scope{start_pos: p.tok.position(), parent: 0}
@@ -687,7 +688,7 @@ pub fn (p mut Parser) name_expr() ast.Expr {
 		p.expr_mod = ''
 		return ast.EnumVal{
 			enum_name: enum_name // lp.prepend_mod(enum_name)
-
+			
 			val: val
 			pos: p.tok.position()
 			mod: mod
@@ -777,7 +778,7 @@ pub fn (p mut Parser) expr(precedence int) ast.Expr {
 			node = ast.SizeOf{
 				typ: sizeof_type
 				// type_name: type_name
-
+				
 			}
 		}
 		.key_typeof {
@@ -904,6 +905,7 @@ pub fn (p mut Parser) expr(precedence int) ast.Expr {
 }
 
 fn (p mut Parser) prefix_expr() ast.PrefixExpr {
+	pos := p.tok.position()
 	op := p.tok.kind
 	if op == .amp {
 		p.is_amp = true
@@ -914,6 +916,7 @@ fn (p mut Parser) prefix_expr() ast.PrefixExpr {
 	return ast.PrefixExpr{
 		op: op
 		right: right
+		pos: pos
 	}
 }
 
@@ -1045,7 +1048,7 @@ fn (p mut Parser) infix_expr(left ast.Expr) ast.Expr {
 		left: left
 		right: right
 		// right_type: typ
-
+		
 		op: op
 		pos: pos
 	}
@@ -1450,7 +1453,7 @@ fn (p mut Parser) const_decl() ast.ConstDecl {
 		fields << ast.Field{
 			name: name
 			// typ: typ
-
+			
 		}
 		exprs << expr
 		// TODO: once consts are fixed reg here & update in checker