String to vertical text

vertical-text.go

package main

import (
	"fmt"
	"strings"
	"unicode/utf8"
)

const (
	delimiter  string = "_"
	centerText bool   = true
)

func extendString(str *string, minLen int) {
	tmpStr := *str

	for i := 0; i < minLen-utf8.RuneCountInString(*str); i++ {
		if i%2 == 0 || !centerText {
			tmpStr += delimiter
			continue
		}
		tmpStr = delimiter + tmpStr
	}

	*str = tmpStr
}

func getSlice(str string) (strSl []string, longestWordLen int) {
	strSl = strings.Split(str, " ")

	for _, word := range strSl {
		wLen := utf8.RuneCountInString(word)
		if longestWordLen < wLen {
			longestWordLen = wLen
		}
	}

	for i := 0; i < len(strSl); i++ {
		extendString(&strSl[i], longestWordLen)
	}

	return
}

func main() {
	str := "Some text here to be converted into vertical"

	strSl, lw := getSlice(str)

	fmt.Println("```")
	for i := 0; i < lw; i++ {
		for _, word := range strSl {
			fmt.Printf("%s ", string([]rune(word)[i]))
		}
		fmt.Print("\n")
	}
	fmt.Println("```")

	// Output with centerText=false:
	// ```
	// S t h t b c i v
	// o e e o e o n e
	// m x r _ _ n t r
	// e t e _ _ v o t
	// _ _ _ _ _ e _ i
	// _ _ _ _ _ r _ c
	// _ _ _ _ _ t _ a
	// _ _ _ _ _ e _ l
	// _ _ _ _ _ d _ _
	// ```

	// Output with centerText=true:
	// ```
	// _ _ _ _ _ c _ v
	// _ _ _ _ _ o _ e
	// S t h _ _ n i r
	// o e e t b v n t
	// m x r o e e t i
	// e t e _ _ r o c
	// _ _ _ _ _ t _ a
	// _ _ _ _ _ e _ l
	// _ _ _ _ _ d _ _
	// ```
}