all: cleanup smartcasts in the compiler (#13639)

vlib/v/checker/checker.v

@@ -3544,13 +3544,10 @@ pub fn (mut c Checker) prefix_expr(mut node ast.PrefixExpr) ast.Type {
 		for mut expr is ast.ParExpr {
 			expr = expr.expr
 		}
-		match expr {
-			ast.BoolLiteral, ast.CallExpr, ast.CharLiteral, ast.FloatLiteral, ast.IntegerLiteral,
-			ast.InfixExpr, ast.StringLiteral, ast.StringInterLiteral {
+		if expr in [ast.BoolLiteral, ast.CallExpr, ast.CharLiteral, ast.FloatLiteral,
+			ast.IntegerLiteral, ast.InfixExpr, ast.StringLiteral, ast.StringInterLiteral] {
 			c.error('cannot take the address of $expr', node.pos)
 		}
-			else {}
-		}
 		if mut node.right is ast.IndexExpr {
 			typ_sym := c.table.sym(node.right.left_type)
 			mut is_mut := false

vlib/v/checker/for.v

@@ -103,10 +103,9 @@ fn (mut c Checker) for_in_stmt(mut node ast.ForInStmt) {
 				value_type = value_type.ref()
 				match node.cond {
 					ast.Ident {
-						if node.cond.obj is ast.Var {
-							obj := node.cond.obj as ast.Var
-							if !obj.is_mut {
-								c.error('`$obj.name` is immutable, it cannot be changed',
+						if mut node.cond.obj is ast.Var {
+							if !node.cond.obj.is_mut {
+								c.error('`$node.cond.obj.name` is immutable, it cannot be changed',
 									node.cond.pos)
 							}
 						}

vlib/v/gen/c/sql.v

@@ -684,10 +684,8 @@ fn (mut g Gen) sql_select(node ast.SqlExpr, expr string, left string) {
 				name := sel
 				s := g.table.find_type_idx('orm.Primitive')
 				if s != 0 {
-					if ident.info is ast.IdentVar {
-						mut info := ident.info as ast.IdentVar
-						info.typ = s
-						ident.info = info
+					if mut ident.info is ast.IdentVar {
+						ident.info.typ = s
 					}
 				}
 				ident.name = name

vlib/v/parser/assign.v

@@ -159,10 +159,9 @@ fn (mut p Parser) partial_assign_stmt(left []ast.Expr, left_comments []ast.Comme
 						return p.error_with_pos('redefinition of `$lx.name`', lx.pos)
 					}
 					mut share := ast.ShareType(0)
-					if lx.info is ast.IdentVar {
-						iv := lx.info as ast.IdentVar
-						share = iv.share
-						if iv.is_static {
+					if mut lx.info is ast.IdentVar {
+						share = lx.info.share
+						if lx.info.is_static {
 							if !p.pref.translated && !p.is_translated && !p.pref.is_fmt
 								&& !p.inside_unsafe_fn {
 								return p.error_with_pos('static variables are supported only in translated mode or in [unsafe] fn',
@@ -170,7 +169,7 @@ fn (mut p Parser) partial_assign_stmt(left []ast.Expr, left_comments []ast.Comme
 							}
 							is_static = true
 						}
-						if iv.is_volatile {
+						if lx.info.is_volatile {
 							is_volatile = true
 						}
 					}

vlib/v/parser/sql.v

@@ -31,17 +31,16 @@ fn (mut p Parser) sql_expr() ast.Expr {
 		p.next()
 		where_expr = p.expr(0)
 		// `id == x` means that a single object is returned
-		if !is_count && where_expr is ast.InfixExpr {
-			e := where_expr as ast.InfixExpr
-			if e.op == .eq && e.left is ast.Ident {
-				if e.left.name == 'id' {
+		if !is_count && mut where_expr is ast.InfixExpr {
+			if where_expr.op == .eq && mut where_expr.left is ast.Ident {
+				if where_expr.left.name == 'id' {
 					query_one = true
 				}
 			}
-			if e.right is ast.Ident {
-				if !p.scope.known_var(e.right.name) {
-					p.check_undefined_variables([e.left], e.right) or {
-						return p.error_with_pos(err.msg(), e.right.pos)
+			if mut where_expr.right is ast.Ident {
+				if !p.scope.known_var(where_expr.right.name) {
+					p.check_undefined_variables([where_expr.left], where_expr.right) or {
+						return p.error_with_pos(err.msg(), where_expr.right.pos)
 					}
 				}
 			}

vlib/v/transformer/transformer.v

@@ -935,8 +935,8 @@ pub fn (mut t Transformer) if_expr(mut node ast.IfExpr) ast.Expr {
 			stmt = t.stmt(mut stmt)
 
 			if i == branch.stmts.len - 1 {
-				if stmt is ast.ExprStmt {
-					expr := (stmt as ast.ExprStmt).expr
+				if mut stmt is ast.ExprStmt {
+					expr := stmt.expr
 
 					match expr {
 						ast.IfExpr {
@@ -976,8 +976,8 @@ pub fn (mut t Transformer) match_expr(mut node ast.MatchExpr) ast.Expr {
 			stmt = t.stmt(mut stmt)
 
 			if i == branch.stmts.len - 1 {
-				if stmt is ast.ExprStmt {
-					expr := (stmt as ast.ExprStmt).expr
+				if mut stmt is ast.ExprStmt {
+					expr := stmt.expr
 
 					match expr {
 						ast.IfExpr {