unify Cut method, return channel instead of array

finalseg/finalseg.go

@@ -9,80 +9,86 @@ var (
 	reSkip = regexp.MustCompile(`(\d+\.\d+|[a-zA-Z0-9]+)`)
 )
 
-func cutHan(sentence string) []string {
-	runes := []rune(sentence)
-	result := make([]string, 0)
-	_, pos_list := viterbi(runes, []byte{'B', 'M', 'E', 'S'})
-	begin, next := 0, 0
-	for i, char := range runes {
-		pos := pos_list[i]
-		switch pos {
-		case 'B':
-			begin = i
-		case 'E':
-			result = append(result, string(runes[begin:i+1]))
-			next = i + 1
-		case 'S':
-			result = append(result, string(char))
-			next = i + 1
+func cutHan(sentence string) chan string {
+	result := make(chan string)
+	go func() {
+		runes := []rune(sentence)
+		_, pos_list := viterbi(runes, []byte{'B', 'M', 'E', 'S'})
+		begin, next := 0, 0
+		for i, char := range runes {
+			pos := pos_list[i]
+			switch pos {
+			case 'B':
+				begin = i
+			case 'E':
+				result <- string(runes[begin : i+1])
+				next = i + 1
+			case 'S':
+				result <- string(char)
+				next = i + 1
+			}
 		}
-	}
-	if next < len(runes) {
-		result = append(result, string(runes[next:]))
-	}
+		if next < len(runes) {
+			result <- string(runes[next:])
+		}
+		close(result)
+	}()
 	return result
 }
 
-func Cut(sentence string) []string {
-	result := make([]string, 0)
+func Cut(sentence string) chan string {
+	result := make(chan string)
 	s := sentence
 	var hans string
 	var hanLoc []int
 	var nonhanLoc []int
-	for {
-		hanLoc = reHan.FindStringIndex(s)
-		if hanLoc == nil {
-			if len(s) == 0 {
-				break
-			}
-		} else if hanLoc[0] == 0 {
-			hans = s[hanLoc[0]:hanLoc[1]]
-			s = s[hanLoc[1]:]
-			for _, han := range cutHan(hans) {
-				result = append(result, han)
-			}
-			continue
-		}
-		nonhanLoc = reSkip.FindStringIndex(s)
-		if nonhanLoc == nil {
-			if len(s) == 0 {
-				break
-			}
-		} else if nonhanLoc[0] == 0 {
-			nonhans := s[nonhanLoc[0]:nonhanLoc[1]]
-			s = s[nonhanLoc[1]:]
-			if nonhans != "" {
-				result = append(result, nonhans)
+	go func() {
+		for {
+			hanLoc = reHan.FindStringIndex(s)
+			if hanLoc == nil {
+				if len(s) == 0 {
+					break
+				}
+			} else if hanLoc[0] == 0 {
+				hans = s[hanLoc[0]:hanLoc[1]]
+				s = s[hanLoc[1]:]
+				for han := range cutHan(hans) {
+					result <- han
+				}
 				continue
 			}
-		}
-		var loc []int
-		if hanLoc == nil && nonhanLoc == nil {
-			if len(s) > 0 {
-				result = append(result, s)
-				break
+			nonhanLoc = reSkip.FindStringIndex(s)
+			if nonhanLoc == nil {
+				if len(s) == 0 {
+					break
+				}
+			} else if nonhanLoc[0] == 0 {
+				nonhans := s[nonhanLoc[0]:nonhanLoc[1]]
+				s = s[nonhanLoc[1]:]
+				if nonhans != "" {
+					result <- nonhans
+					continue
+				}
 			}
-		} else if hanLoc == nil {
-			loc = nonhanLoc
-		} else if nonhanLoc == nil {
-			loc = hanLoc
-		} else if hanLoc[0] < nonhanLoc[0] {
-			loc = hanLoc
-		} else {
-			loc = nonhanLoc
+			var loc []int
+			if hanLoc == nil && nonhanLoc == nil {
+				if len(s) > 0 {
+					result <- s
+					break
+				}
+			} else if hanLoc == nil {
+				loc = nonhanLoc
+			} else if nonhanLoc == nil {
+				loc = hanLoc
+			} else if hanLoc[0] < nonhanLoc[0] {
+				loc = hanLoc
+			} else {
+				loc = nonhanLoc
+			}
+			result <- s[:loc[0]]
+			s = s[loc[0]:]
 		}
-		result = append(result, s[:loc[0]])
-		s = s[loc[0]:]
-	}
+		close(result)
+	}()
 	return result
 }