Comment by mmphosis

In the 80's I got the gist of spellchecker algorithms.

An Apple II spellchecker that I used a few times seemed to spell-check using brute force means with the dictionary filling an separate 143K floppy disk. It was a somewhat slow batch-like one document-at-time operation, but it was good enough to be useful.

As a programmer in the 80's, I saw a spellchecker that used a small hash table to tell whether a word was misspelled or not. The hash table could be made even smaller if we limited the dictionary to about 16000 of the more common words. If I remember correctly, the smallest hash table was generated as an array of 16 bit integers in the source code before compiling and it's small footprint kept in memory of the built program. Once a word was identified as a misspelling, using a very fast hash look-up, suggestions of words could be pulled from the actual dictionary on disk. Using the hash, there was the possibility of false spellings. Maybe this was a Bloom Filter.