TheAlgorithms/Go · error

ErrNoTextToEncrypt

ErrNoTextToEncrypt

Error message

%w: cannot encrypt a text, %q, ending with the placeholder char %q

What it means

Encrypt pads text with a placeholder rune; input that already ends with that placeholder would make correct unpadding ambiguous on decrypt, so Encrypt refuses it, wrapping ErrNoTextToEncrypt with the text and placeholder shown.

Source

Thrown at cipher/transposition/transposition.go:64

		if wordSet[i] == subString {
			return i
		}
	}
	return 0
}

func Encrypt(text []rune, keyWord string) ([]rune, error) {
	key := getKey(keyWord)
	keyLength := len(key)
	textLength := len(text)
	if keyLength <= 0 {
		return nil, ErrKeyMissing
	}
	if textLength <= 0 {
		return nil, ErrNoTextToEncrypt
	}
	if text[len(text)-1] == placeholder {
		return nil, fmt.Errorf("%w: cannot encrypt a text, %q, ending with the placeholder char %q", ErrNoTextToEncrypt, text, placeholder)
	}
	n := textLength % keyLength

	for i := 0; i < keyLength-n; i++ {
		text = append(text, placeholder)
	}
	textLength = len(text)
	var result []rune
	for i := 0; i < textLength; i += keyLength {
		transposition := make([]rune, keyLength)
		for j := 0; j < keyLength; j++ {
			transposition[key[j]-1] = text[i+j]
		}
		result = append(result, transposition...)
	}
	return result, nil
}

View on GitHub (pinned to 5ba447ec5f)

Solutions

1. Strip or escape the placeholder character from the plaintext before encrypting
2. Choose a placeholder guaranteed absent from your plaintext alphabet
3. Detect via errors.Is(err, ErrNoTextToEncrypt) and sanitize then retry

When it happens

Trigger: Thrown at cipher/transposition/transposition.go:64 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of TheAlgorithms/Go@5ba447ec5f (2026-09-02). Data as JSON: /api/errors/e2125b418c23b132. Report an issue: GitHub.