Initial QSfera import

Server/vendor/github.com/bbalet/stopwords/levenshtein.go

@@ -0,0 +1,52 @@
+// Copyright 2015 Benjamin BALET. All rights reserved.
+// Use of this source code is governed by the BSD license
+// license that can be found in the LICENSE file.
+
+// Package stopwords implements the Levenshtein Distance algorithm to evaluate the diference
+// between 2 strings
+package stopwords
+
+// LevenshteinDistance compute the LevenshteinDistance between 2 strings
+// it removes useless spaces and stop words from a byte slice.
+// BCP 47 or ISO 639-1 language code (if unknown, we'll apply english filters).
+// If cleanHTML is TRUE, remove HTML tags from content and unescape HTML entities.
+func LevenshteinDistance(contentA []byte, contentB []byte, langCode string, cleanHTML bool) int {
+	stringA := Clean(contentA, langCode, cleanHTML)
+	stringB := Clean(contentB, langCode, cleanHTML)
+	distance := levenshteinAlgo(&stringA, &stringB)
+	return distance
+}
+
+// levenshteinAlgo compute the LevenshteinDistance between 2 strings
+func levenshteinAlgo(a, b *[]byte) int {
+	la := len(*a)
+	lb := len(*b)
+	d := make([]int, la+1)
+	var lastdiag, olddiag, temp int
+
+	for i := 1; i <= la; i++ {
+		d[i] = i
+	}
+	for i := 1; i <= lb; i++ {
+		d[0] = i
+		lastdiag = i - 1
+		for j := 1; j <= la; j++ {
+			olddiag = d[j]
+			min := d[j] + 1
+			if (d[j-1] + 1) < min {
+				min = d[j-1] + 1
+			}
+			if (*a)[j-1] == (*b)[i-1] {
+				temp = 0
+			} else {
+				temp = 1
+			}
+			if (lastdiag + temp) < min {
+				min = lastdiag + temp
+			}
+			d[j] = min
+			lastdiag = olddiag
+		}
+	}
+	return d[la]
+}