Just a hash map ain't gonna work. The only reason spell checking is perceived as a solved problem is availability of libraries. Here's an open source example https://github.com/hunspell/hunspell way above 10k lines of code.
I speak 4 languages, and in my experience what's in Microsoft Office is the best one I used so far.
> Hunspell is a long-living, complicated, almost undocumented piece of software, and it was our feeling that the significant part of human knowledge is somehow "locked" in a form of a large C++ project. That's how Spylls was born: as an attempt to "unlock" it, via well-structured and well-documented implementation in a high-level language.
It's incredible how much work has been done (along with documenting algorithms!) in this one-man project.
If you only need English, the complexity of Hunspell is not required.
I still haven't found a decent Hungarian spell checker, they get confused by rare words that have the same letters as a very common word, but different accents.
E.g.: The word "és" means "and", which makes it much more common than "es", which is the word root for "fall" and is rarely used without a suffix like "esett" or "estek".
I'm yet to see a spellchecker that's smart enough to fix "something es something" but not "le es".
First of all it's a verb with -ik ending so you can't write "es", the root lexical word is "esik".
Second you never use anything like "le es" because generaly you always have to use the verb and prefix together ("leesett", "leesik" etc.) unless you use a commanding form ("ess le") or a modal verb ("le akart esni, "le fog esni" etc.)
"le es" is strictly wrong because it's the wrong verb (should be "esik") and you have to write together ("leesik") so obviously a spellchecker picks that up.
But if you're right (seems like you are), then why do spell checkers not pick up on "es" as misspelled?
Mostly for numerals:
"I arrive with the train at 7" [as in 7 o'clock] = "A 7-es vonattal érkezem"
"M7 motorway" = "M7-es autópálya"
"50m² room" = "50m²-es szoba"
But it's also used with foreign names and full names.
Currently spell checking just checks words from a dictionary. Its 1% of work. Or even less.
Microsoft Word used to have awesome spell checking, grammar checking, etc back in 2000 for Russian language. It seems to be degraded since then. But the fact is, this problem was solved. It checked for spelling, for grammar, for punctuation. I would expect that kind of functionality working in every OS textbox by now.
Say hello to homophones, ambiguous phrases and double meaning.
In Spanish a lot of verbs share the singular first and third persons. "Estaba" can mean "I was" or "He/she was.". Or "fuimos", (we were); but also "we went".