By the time you did a scan through all of the text to split it by words (by looking for spaces), you could've run the corpus up against the pre-computed Trie an

By the time you did a scan through all of the text to split it by words (by looking for spaces), you could've run the corpus up against the pre-computed Trie and decided whether it was kosher or not. Not to mention the overhead of computing permutations for character substitutions in words.