// reads a file and stores trigrams in database
func ParseFile(filename string) {
content := ReadFile(filename)
news_lines := ExtractNewsLine(content)
Connect(database_name, true)
for _, line := range news_lines {
id := PostNews(line)
for _, trigram := range ngram.BuildNGram(line, 3) {
PutTrigram(trigram, id)
}
}
}
// returns n=count titles matching to the title
func GetBestMatches(title string, count int) []string {
var trigram_matches []int
// first calculate ngrams of the search string
for _, trigram := range ngram.BuildNGram(title, 3) {
for _, match := range data.GetIdsOfTrigram(trigram) {
trigram_matches = append(trigram_matches, match)
}
}
// TODO: now get the *count* most frequent news ids
frequencies := map[int]int{}
for _, id := range trigram_matches {
_, contains := frequencies[id]
if contains {
frequencies[id] += 1
} else {
frequencies[id] = 1
}
}
// now sort according to the count
sorted := SortByFrequency(trigram_matches, frequencies)
return_val := []int{}
for i := 0; i <= count; i += 1 {
return_val = append(return_val, sorted[i])
}
// get the according titles
titles := []string{}
for id := range return_val {
titles = append(titles, data.GetNewsTitle(id))
}
return titles
}