diff --git a/correct.c b/correct.c index abad321..d68b3b7 100644 --- a/correct.c +++ b/correct.c @@ -33,7 +33,7 @@ * * A little about how it works, and probability theory: * - * When given an identifier (which we will denote I), we're essentially + * When given an identifier (which we will denote I), we're essentially * just trying to choose the most likely correction for that identifier. * (the actual "correction" can very well be the identifier itself). * There is actually no way to know for sure that certian identifers @@ -44,9 +44,20 @@ * out of all possible corrections that maximizes the probability of C * for the original identifer I. * - * Bayes' Therom suggests something of the following: + * Thankfully there exists some theroies for probalistic interpretations + * of data. Since we're operating on two distictive intepretations, the + * transposition from I to C. We need something that can express how much + * degree of I should rationally change to become C. this is called the + * Bayesian interpretation. You can read more about it from here: + * http://www.celiagreen.com/charlesmccreery/statistics/bayestutorial.pdf + * (which is probably the only good online documentation for bayes theroy + * no lie. Everything else just sucks ..) + * + * Bayes' Thereom suggests something like the following: * AC P(I|C) P(C) / P(I) - * Since P(I) is the same for every possibly I, we can ignore it giving + * + * However since P(I) is the same for every possibility of I, we can + * complete ignore it giving just: * AC P(I|C) P(C) * * This greatly helps visualize how the parts of the expression are performed @@ -78,7 +89,7 @@ * * A little information on additional algorithms used: * - * Initially when I implemented this corrector, it was very slow. + * Initially when I implemented this corrector, it was very slow. * Need I remind you this is essentially a brute force attack on strings, * and since every transformation requires dynamic memory allocations, * you can easily imagine where most of the runtime conflated. Yes @@ -87,7 +98,7 @@ * shock to me. A forward allocator (or as some call it a bump-point * allocator, or just a memory pool) was implemented. To combat this. * - * But of course even other factors were making it slow. Initially + * But of course even other factors were making it slow. Initially * this used a hashtable. And hashtables have a good constant lookup * time complexity. But the problem wasn't in the hashtable, it was * in the hashing (despite having one of the fastest hash functions @@ -99,18 +110,19 @@ * * Future Work (If we really need it) * - * Currently we can only distinguishes one source of error in the + * Currently we can only distinguishes one source of error in the * language model we use. This could become an issue for identifiers * that have close colliding rates, e.g colate->coat yields collate. * - * Currently the error model has been fairly trivial, the smaller the + * Currently the error model has been fairly trivial, the smaller the * edit distance the smaller the error. This usually causes some un- * expected problems. e.g reciet->recite yields recipt. For QuakeC * this could become a problem when lots of identifiers are involved. * - * Our control mechanisim could use a limit, i.e limit the number of + * Our control mechanisim could use a limit, i.e limit the number of * sets of edits for distance X. This would also increase execution - * speed considerably. + * speed considerably. + * */ @@ -163,12 +175,12 @@ static GMQCC_INLINE char *correct_pool_claim(const char *data) { } /* - * A fast space efficent trie for a disctonary of identifiers. This is + * A fast space efficent trie for a dictionary of identifiers. This is * faster than a hashtable for one reason. A hashtable itself may have * fast constant lookup time, but the hash itself must be very fast. We * have one of the fastest hash functions for strings, but if you do a * lost of hashing (which we do, almost 3 million hashes per identifier) - * a hashtable becomes slow. Very Very Slow. + * a hashtable becomes slow. */ correct_trie_t* correct_trie_new() { correct_trie_t *t = (correct_trie_t*)mem_a(sizeof(correct_trie_t)); @@ -440,7 +452,8 @@ static char **correct_known(correct_trie_t* table, char **array, size_t rows, si end = correct_edit(array[itr]); row = correct_size(array[itr]); - for (; jtr < row; jtr++) { + /* removing jtr=0 here speeds it up by 100ms O_o */ + for (jtr = 0; jtr < row; jtr++) { if (correct_find(table, end[jtr]) && !correct_exist(res, len, end[jtr])) { res = correct_known_resize(res, &nxt, len+1); res[len++] = end[jtr];