parser: make let shift operators work with all types

vlib/bitfield/bitfield.v

@@ -34,7 +34,7 @@ fn bitslot(size int) int {
 }
 
 fn bitget(instance BitField, bitnr int) int {
-	return (instance.field[bitslot(bitnr)] >> u32(bitnr % SLOT_SIZE)) & 1
+	return (instance.field[bitslot(bitnr)] >> (bitnr % SLOT_SIZE)) & u32(1)
 }
 
 fn bitset(instance mut BitField, bitnr int) {

vlib/compiler/parser.v

@@ -2411,15 +2411,15 @@ fn (p mut Parser) expression() string {
 		else {
 			p.next()
 			p.gen(' << ')
-			p.check_types(p.expression(), typ)
-			return 'int'
+			p.check_types(p.expression(), 'integer')
+			return typ
 		}
 	}
 	if p.tok == .righ_shift {
 		p.next()
 		p.gen(' >> ')
-		p.check_types(p.expression(), typ)
-		return 'int'
+		p.check_types(p.expression(), 'integer')
+		return typ
 	}
 	// + - | ^
 	for p.tok in [.plus, .minus, .pipe, .amp, .xor] {

vlib/compiler/table.v

@@ -201,13 +201,17 @@ pub fn (t &Table) debug_fns() string {
 // fn (types array_Type) print_to_file(f string)  {
 // }
 const (
-	number_types = ['number', 'int', 'i8', 'i16', 'u16', 'u32', 'byte', 'i64', 'u64', 'f32', 'f64']
+	integer_types = ['int', 'i8', 'byte', 'i16', 'u16', 'u32', 'i64', 'u64']
 	float_types   = ['f32', 'f64']
 	reserved_type_param_names = ['R', 'S', 'T', 'U', 'W']
 )
 
 fn is_number_type(typ string) bool {
-	return typ in number_types
+	return typ in integer_types || typ in float_types
+}
+
+fn is_integer_type(typ string) bool {
+	return typ in integer_types
 }
 
 fn is_float_type(typ string) bool {
@@ -671,6 +675,15 @@ fn (p mut Parser) check_types2(got_, expected_ string, throw bool) bool {
 	if is_number_type(got) && is_number_type(expected) && p.is_const_literal {
 		return true
 	}
+
+	if expected == 'integer' {
+		if is_integer_type(got) {
+			return true
+		} else {
+			p.error('expected type `$expected`, but got `$got`')
+		}
+	}
+
 	expected = expected.replace('*', '')
 	got = got.replace('*', '')
 	if got != expected {

vlib/compiler/tests/shift_test.v

@@ -0,0 +1,33 @@
+fn test_shift_operators() {
+
+	// check that shift works with all integer types 
+	// as the right-hand side operand
+	a := 1
+	b := 1024
+	i := 10
+
+	assert b == a << i8(i)
+	assert b == a << byte(i)
+	assert b == a << i16(i)
+	assert b == a << u16(i)
+	assert b == a << int(i)
+	assert b == a << u32(i)
+	assert b == a << i64(i)
+	assert b == a << u64(i)
+
+	assert a == b >> i8(i)
+	assert a == b >> byte(i)
+	assert a == b >> i16(i)
+	assert a == b >> u16(i)
+	assert a == b >> int(i)
+	assert a == b >> u32(i)
+	assert a == b >> i64(i)
+	assert a == b >> u64(i)
+
+	// check that shift operation result type is
+	// the same as the type of the left-hand side operand
+	mut c := u64(0)
+	d := u64(1)
+	c = d << i8(63)
+	assert c == 9223372036854775808
+}

vlib/hash/crc32/crc32.v

@@ -27,8 +27,8 @@ fn(c mut Crc32) generate_table(poly int) {
 	for i := 0; i < 256; i++ {
 		mut crc := u32(i)
 		for j := 0; j < 8; j++ {
-			if crc&u32(1) == u32(1) {
-				crc = u32((crc >> u32(1)) ^ poly)
+			if crc & u32(1) == u32(1) {
+				crc = (crc >> 1) ^ u32(poly)
 			} else {
 				crc >>= u32(1)
 			}