index package:text

index :: HasCallStack => Text -> Int -> Char
text Data.Text
O(n) Text index (subscript) operator, starting from 0.
index :: HasCallStack => Stream Char -> Int -> Char
text Data.Text.Internal.Fusion
O(n) stream index (subscript) operator, starting from 0. Properties 
index (stream t) n  = index t n
index :: HasCallStack => Stream Char -> Int64 -> Char
text Data.Text.Internal.Lazy.Fusion
O(n) stream index (subscript) operator, starting from 0.
index :: HasCallStack => Text -> Int64 -> Char
text Data.Text.Lazy
O(n) Text index (subscript) operator, starting from 0.
indexI :: (HasCallStack, Integral a) => Stream Char -> a -> Char
text Data.Text.Internal.Fusion.Common
O(n) Stream index (subscript) operator, starting from 0. Properties 
indexI (stream t) n = index t n
findIndex :: (Char -> Bool) -> Text -> Maybe Int
text Data.Text
O(n) The findIndex function takes a predicate and a Text and returns the index of the first element in the Text satisfying the predicate.
unsafeIndex :: Array -> Int -> Word8
text Data.Text.Array
Unchecked read of an immutable array. May return garbage or crash on an out-of-bounds access.
findIndex :: (Char -> Bool) -> Stream Char -> Maybe Int
text Data.Text.Internal.Fusion
The findIndex function takes a predicate and a stream and returns the index of the first element in the stream satisfying the predicate. Properties 
findIndex p . stream  = findIndex p
findIndexI :: Integral a => (Char -> Bool) -> Stream Char -> Maybe a
text Data.Text.Internal.Fusion.Common
The findIndexI function takes a predicate and a stream and returns the index of the first element in the stream satisfying the predicate. Properties 
findIndexI p . stream = findIndex p