kitetorrent/io.github.yuroyami.kitetorrent.util/StringUtil

StringUtil

Small, locale-independent string helpers. This is a pure-Kotlin port of the portable parts of libtorrent's string_util.cpp and string_util.hpp (plus base64encode from escape_string.cpp).

These deliberately reimplement the C ctype predicates (isalpha, isspace, …) over the ASCII range only, exactly like libtorrent does, so that behaviour is identical on every platform regardless of the C locale. That is why libtorrent wrote its own. Anything in string_util.cpp that depends on sockets, addresses, the global RNG, locale conversion, or raw C memory management (parse_listen_interfaces, print_listen_interfaces, url_random, allocate_string_copy, convert_to_native, is_i2p_url, …) is intentionally not ported here.

Where libtorrent returns std::pair<string_view, string_view> (zero-copy views into the original buffer), the Kotlin equivalents return Pair of copies; the splitting semantics are preserved byte-for-byte.

Functions

base64encode

fun base64encode(bytes: ByteArray): String

libtorrent base64encode: standard base64 with = padding. Operates on raw bytes (the C++ takes a std::string but treats it as a byte buffer).

fun base64encode(s: String): String

Convenience: base64-encode the UTF-8 bytes of s.

convertPathToPosix

fun convertPathToPosix(path: String): String

libtorrent convert_path_to_posix (escape_string.cpp): replace every \ with /.

ensureTrailingSlash

fun ensureTrailingSlash(url: String): String

libtorrent ensure_trailing_slash (inline in string_util.hpp).

isAlpha

fun isAlpha(c: Char): Boolean

libtorrent is_alpha: ASCII letter.

isDigit

fun isDigit(c: Char): Boolean

libtorrent is_digit (inline in string_util.hpp): ASCII decimal digit.

isPrint

fun isPrint(c: Char): Boolean

libtorrent is_print: printable ASCII (space through '~', i.e. 32..126).

isSpace

fun isSpace(c: Char): Boolean

libtorrent is_space: ASCII whitespace. Note this matches the C set ' ' \t \n \r \f \v, and not Kotlin's Char.isWhitespace, which is Unicode-aware.

ltrim

fun ltrim(s: String): String

libtorrent ltrim: leading-whitespace-only strip.

parseCommaSeparatedString

fun parseCommaSeparatedString(input: String): List<String>

libtorrent parse_comma_separated_string: split input on commas, trimming leading and trailing ASCII whitespace from each element. Empty elements are kept (the C++ pushes back the possibly-empty substring), matching the outgoing_interfaces-style parsing.

splitString

fun splitString(last: String, sep: Char): Pair<String, String>

libtorrent split_string: find separator sep in last. If found, return the part before it and the remainder after it (separator dropped). If not found, return (last, "").

splitStringQuotes

fun splitStringQuotes(last: String, sep: Char): Pair<String, String>

libtorrent split_string_quotes: like splitString, but if the string starts with a double-quote ("), and the separator itself is not ", then separators are ignored until the closing quote. Faithful port of the index-walking in the C++.

stringBeginsNoCase

fun stringBeginsNoCase(prefix: String, s: String): Boolean

libtorrent string_begins_no_case: true if s begins with prefix, compared case-insensitively over ASCII. (In the C++ the first argument is the prefix and the loop runs to the prefix's NUL.)

stringEndsWith

fun stringEndsWith(s1: String, s2: String): Boolean

libtorrent string_ends_with: true if s1 ends with s2.

stringEqualNoCase

fun stringEqualNoCase(s1: String, s2: String): Boolean

libtorrent string_equal_no_case: ASCII case-insensitive equality.

stripString

fun stripString(s: String): String

libtorrent strip_string: drop leading and trailing ASCII whitespace, using the full isSpace set (space tab nl cr ff vt).

toLower

fun toLower(c: Char): Char

libtorrent to_lower: ASCII-only lower-casing (leaves non-ASCII untouched).

toLowerAscii

fun toLowerAscii(s: String): String

ASCII-only lower-cased copy of s; locale-independent, unlike String.lowercase.

toString

fun toString(n: Long): String

libtorrent to_string(std::int64_t): decimal text of n with a well-defined, locale-independent result. It handles Long.MIN_VALUE correctly. That magnitude is not representable as a positive signed Long, so the digits are produced via unsigned arithmetic, exactly as the C++ does.

trim

fun trim(s: String): String

libtorrent trim (escape_string.cpp): strips only " \t\n\r". This is the narrower set the trim helper uses (no form-feed, no vertical-tab), kept distinct from stripString to stay faithful to both call sites.