2 files changed, 6 insertions(+), 3 deletions(-)

M src/Data/Text/ParagraphLayout/Internal/Plain.hs
M src/Data/Text/ParagraphLayout/Internal/Span.hs

@@ 263,6 263,7 @@ runBreaksFromSpan run spanBreaks =
 isEndSpace :: Char -> Bool
 isEndSpace c = c `elem` [' ', '\t', '\x1680']
 
--- TODO: Identify and correct for differences between the two.
+-- TODO: Convert from IETF BCP 47 language tag to ICU locale identifier,
+--       possibly with an algorithm to find the best matching available locale.
 localeFromLanguage :: String -> LocaleName
-localeFromLanguage x = Locale x
+localeFromLanguage x = Locale $ map (\c -> if c == '-' then '_' else c) x

@@ 30,7 30,9 @@ data Span = Span
 data SpanOptions = SpanOptions
 
     { spanLanguage :: String
-    -- ^ Used for selecting the appropriate glyphs and line breaking rules.
+    -- ^ IETF BCP 47 language tag, such as the value expected to be found in
+    -- the HTML @lang@ attribute.
+    -- Used for selecting the appropriate glyphs and line breaking rules.
 
     }
     deriving (Eq, Read, Show)