Ngrams algorithm

ngrams.go

package main

import (
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {

	if len(os.Args) < 3 {
		fmt.Println("Please provide a sentence and an N-Gram ordering .e.g.")
		fmt.Println("   \"I have a sentence\" 3")
		return
	}

	var sentence string = os.Args[1]
	ngramOrdering, err := strconv.Atoi(os.Args[2])

	if err != nil {
		fmt.Println("Please provide a valid ngram ordering")
		return
	}

	result := getNgrams(sentence, ngramOrdering)

	for _, r := range result {
		fmt.Println(r)
	}
}

func getNgrams(input string, ngrams int) []string {
	tokens := strings.Fields(input)
	var result []string = make([]string, 0)

	for i := 0; i < len(tokens); i++ {
		if i+ngrams <= len(tokens) {
			result = append(result, selectNgramWindow(i, ngrams, tokens))
		}
	}

	return result
}

func selectNgramWindow(index, ngram int, tokens []string) string {
	var result string = ""

	for i := 0; i < ngram; i++ {
		if index+i < len(tokens) {
			result += tokens[index+i] + " "
		}
	}

	return strings.TrimSpace(result)
}