@@ -1,6 +1,7 @@
11module VerifyUtf8Width where
22import Verify
33
4+import Graphics.Text.Width
45import Graphics.Vty.Attributes
56import Graphics.Vty.Picture
67
@@ -10,9 +11,18 @@ sw_is_1_column (SingleColumnChar c) = image_width (char def_attr c) == 1
1011dw_is_2_column :: DoubleColumnChar -> Bool
1112dw_is_2_column (DoubleColumnChar c) = image_width (char def_attr c) == 2
1213
14+dc_string_is_even :: NonEmptyList DoubleColumnChar -> Bool
15+dc_string_is_even (NonEmpty dw_list) =
16+ even $ safe_wcswidth [ c | DoubleColumnChar c <- dw_list ]
17+
18+safe_wcwidth_for_control_chars :: Bool
19+safe_wcwidth_for_control_chars = 0 == safe_wcwidth '\NUL'
20+
1321tests :: IO [Test]
1422tests = return
1523 [ verify "sw_is_1_column" sw_is_1_column
1624 , verify "dw_is_2_column" dw_is_2_column
25+ , verify "a string of double characters is an even width" dc_string_is_even
26+ , verify "safe_wcwidth provides a width of 0 for chars without widths" safe_wcwidth_for_control_chars
1727 ]
1828