4.23.2 Base58 Encoding

4.23.2.1 Validation

(base58-valid? str [start = 0] [end = (string-length str)] [alphabet = base58-btc-alphabet]) returns a boolean indicating whether every character in str[start,end) belongs to the selected alphabet. Both base58-btc-alphabet and base58-flickr-alphabet are supported. They use the same characters in different orders, so membership validation gives the same result for either alphabet.

The empty substring is valid. Whitespace, padding, non-ASCII characters, and the excluded characters 0, O, I, and l are invalid. The scan does not allocate a substring or decoded bytes, and does not perform numeric conversion.

str must be a string; start and end must be fixnums satisfying 0 <= start <= end <= (string-length str). Invalid argument types or bounds raise ContractViolation, rather than returning #f.

4.23.2.2 Encoding And Decoding

(base58-encode bytes [alphabet = base58-btc-alphabet]) returns a string. (base58-decode str [alphabet = base58-btc-alphabet]) returns a u8vector and raises IOError for invalid characters. Leading zero bytes are preserved as leading zero digits (1 in both supplied alphabets). Empty input encodes or decodes to empty output. The validator does not change either codec’s behavior.