I'm looking for an equivalent of 'isInfixOf' to filter an element from a list

Question

I have a list of words (strings) like text = ["hello","world","me"] and I am looking for an equivalent of isInfixOf to filter this list but which should return True only if the word is fully written.

expected output:

 >>> hello -> True

 >>> hell -> False

text = ["hello world", "hello guys","nice guys"]
word = "hello"
word2 = "hell"

toSplit :: String -> [String]
toSplit = splitWords . dropWhile (==' ') 
    where
        splitWords "" = []
        splitWords s = 
          let word = takeWhile (/=' ') s
              (_, rest) = splitAt (length word) s
          in word : splitWords (dropWhile (==' ') rest)


output:

*Main> filter (isInfixOf (word)) text["hello world","hello guys"]
*Main> filter (isInfixOf (word2)) text
["hello world","hello guys"]
*Main> 

I tried to split the text before, but I have an error:

*Main> newText = map(toSplit) text
*Main> filter (isInfixOf (word2)) newText

<interactive>:77:28: error:
    • Couldn't match type ‘[Char]’ with ‘Char’
      Expected type: [[Char]]
        Actual type: [[String]]
    • In the second argument of ‘filter’, namely ‘newText’
      In the expression: filter (isInfixOf (word2)) newText
      In an equation for ‘it’: it = filter (isInfixOf (word2)) newText
*Main> filter (isInfixOf (word)) newText

<interactive>:78:27: error:
    • Couldn't match type ‘[Char]’ with ‘Char’
      Expected type: [[Char]]
        Actual type: [[String]]
    • In the second argument of ‘filter’, namely ‘newText’
      In the expression: filter (isInfixOf (word)) newText
      In an equation for ‘it’: it = filter (isInfixOf (word)) newText
*Main> 

Answer 1

You need to split each string into a list of words, then check if that list contains the target word. To do this, you can use the function words :: String -> [String]:

containsWord :: String -> String -> Bool
containsWord word = elem word . words

Then you can filter using containsWord word:

> containsWord "hello" "hello world"
True

> containsWord "hell" "hello world"
False

> filter (containsWord "hello") ["hello world", "hello guys", "nice guys"]
["hello world", "hello guys"]