move escId to BuilderQQ

make-pages/BuilderQQ.hs

@@ -2,7 +2,7 @@
 module BuilderQQ
   (b,
    Builder, toLazyText, fromText, fromString, fromChar,
-   textMap, ifJust)
+   textMap, ifJust, escId)
 where
 
 import Data.Char (isLower, isSpace, isDigit, isAlphaNum)
@@ -189,3 +189,12 @@ textMap f = Text.foldl' (\buf c -> buf <> f c) mempty
 
 ifJust :: Monoid b => Maybe a -> (a -> b) -> b
 ifJust x f = maybe mempty f x
+
+
+escId :: Text -> Builder
+escId = foldMap esc1 . Text.unpack where
+  esc1 c | isSpace c       = ""
+         | latin1Special c = "_"
+         | otherwise       = fromChar c
+  latin1Special c =
+    c <= 'ÿ' && not (isAlphaNum c) && c /= '-'