This is an improved version of the spell checker from Shelz's COTM "A Comprehensive Spell Checker" at txtCodeId=65992. It includes a modified Russell Soundex phonetic algorithm and the Levenshtein Distance algorithm. It is now a *very* fast and effective spell checker solution...
It impressed me with its most effective and concise spell checking algorithms, a perfect demo project, and the smart way it provided a complete database of words in a 1.3 MB download...
But like many other spell checkers it had a common limitation...
The basic aim of the Soundex algorithm is for names with the same pronunciation to be encoded the same so that matching can occur despite minor differences in spelling. The Soundex for a word consists of a letter followed by three numbers: the letter is the first letter of the name, and the numbers encode the remaining consonants. Therefore, only words beginning with the same first letter are compared for similar pronunciation using the standard algorithm...
This version of the Russell Soundex algorithm has been modified to allow the matching of words that start with differing first letters so as not to assume that the first letter is always known. In this version the encoding always begins with the first letter of the word...
The Levenshtein Distance algo marries perfectly with the results to identify the correct spelling for the given (mis-spelt) word every time! A search on the word "apolstry" with the minimum successful Levenshtein Distance returns just four words where one of these is "upholstery"...
[Version 2] - Removed the dependence on the DAO library and is contained in a single text file. The Soundex encoding has been extended to include a 'reverse soundex' of all words (encoding from the end of the words backwards as well). On my 866MHz PC the access database took minutes to create the words database and was quite slow processing the lookup query, particularly after adding the reverse soundex to the query. Creating the database now takes 25 seconds and the lookups are now fast enough to be in real time (updated with every text entry change event)...
[Update 18 Feb 09] - Improved speed of data loading at form load from 1.2 to 0.9 seconds on 866MHz PC. On my Athlon 4000+ the database builds in under 10 seconds and the data loads at form load in well under 0.5 seconds. On your average PC this would be fast enough to unload the form every use and re-load it when needed without the user experiencing any delay...
[Update 21 Feb 09] - Added code to normalise words file to expected format (removes empty lines and converts comma delimited files)...
[Version 3] - Considerably improved speed of both Soundex and Levenshtein Distance algos by eliminating Mid$(s,i,1) creating a temp string for every character and comparing chars, to using copymemory to grab the unicode value and comparing int's instead. I think the MidI code used was authored by Bruce McKinney, but if it is yours let me know and I will give you credit...
[Version 4] - Injected some asm machine code into the database creation sub and now builds the database in a blink! Big thanks to Robert Rayment for your generous help with as$embler
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If I wanted to use other language than English, could i use soundex?? and build another wordlist? Or soundex just available in English?? Please reply me... (If this comment was disrespectful, please report it.)
Sorry for the late response, must have missed your comment
The short answer is 'no' :(
The long answer is 'maybe'. Some other languages do have common letters with similar pronunciation to English letters and so may work but I think you would need to reproduce the soundex rules to apply them to the pronunciation of the letters in your intended language.
I do not have the phonetic knowledge to produce even this English algo, so I could not do so for another language.
Happy coding, Rd :) (If this comment was disrespectful, please report it.)
Please note: the included words list is rather dodgy. It contains many invalid words. I would try to validate all the words if it was not so time consuming.
You can replace the file simply by overwriting the Words.dat file with your own list named Words.dat and the program will update the db with your list.
Happy coding, Rd :) (If this comment was disrespectful, please report it.)
Hi, Cpiuld you adapt the program to work in realtime and to automatically hyphenate the words - as and when appropriate Also what about adding a thesaurus too it
(If this comment was disrespectful, please report it.)
Yes it already works in real time! Just pop up the spell checker with a word hi-lighted in the main window and it will spell check that word - or in the spell checker type in the word and it will update with each keystroke.
Hyphenating the words simply requires that you add the hyphenated words to the words database file. You can also find alternative words lists that already include all hyphenated variants of words. The words database is just a text file with each word occupying a single line in the text, so replacing the database is as simple as placing your alternate words list in the program path and renaming that file to WORDS.DAT.
cont'd (If this comment was disrespectful, please report it.)
Note that I have optimized the loading process by sorting the words list so that it does not require this processing on every load of the database - an unsorted list will work correctly but found matches will not be in any particular order which may not appear very professional.
As for a thes - well that is a great idea but is really a whole new and very different project with some type of links for all words to related (and opposite) words. This could be done using the current (or alternate) words list by adding the relationship data - perhaps contained in another file?
Anyway, feel free to correspond on this or any other subject.
Happy coding, Rd :) (If this comment was disrespectful, please report it.)
Just a quick note about the included words list - I have replaced the original 450,000 word rubbish to a smaller but ideal common use word list with maybe no rubbish words.
Happy coding, Rd :) (If this comment was disrespectful, please report it.)
Yes I still think 'wow' about how well these two algos work together as a spell checker Happy coding, Rd :) (If this comment was disrespectful, please report it.)
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8/18/2006 11:47:11 AM: 
