std.string

concat function

pub fn concat(a: string, b: string): string

The two joined — what + on strings compiles to.

stdlib/std/string.lyr:19

fromInt function

pub fn fromInt(value: int): string

The decimal text of the value.

stdlib/std/string.lyr:22

fromUint function

pub fn fromUint(value: uint): string

The decimal text of an unsigned value.

stdlib/std/string.lyr:27

fromFloat function

pub fn fromFloat(value: float): string

The decimal text of the value.

stdlib/std/string.lyr:29

fromBool function

pub fn fromBool(value: bool): string

"true" or "false".

stdlib/std/string.lyr:31

fromChar function

pub fn fromChar(value: char): string

The character as a one-character string.

stdlib/std/string.lyr:33

repeat function

pub fn repeat(value: string, count: int): string

The string repeated count times — what s * n compiles to.

stdlib/std/string.lyr:38

length function

pub fn length(value: string): int

The length in code points — the unit every position in this module uses.

stdlib/std/string.lyr:49

charAt function

pub fn charAt(value: string, index: int): char

The character at a code-point position. O(n): a position counts code points, not bytes.

stdlib/std/string.lyr:52

substring function

pub fn substring(value: string, start: int, count: int): string

count characters from start, both in code points.

stdlib/std/string.lyr:55

indexOf function

pub fn indexOf(value: string, needle: string): int

The first position of needle in code points, or -1 — ready for charAt and substring.

stdlib/std/string.lyr:62

contains function

pub fn contains(value: string, needle: string): bool

Whether needle occurs.

stdlib/std/string.lyr:65

startsWith function

pub fn startsWith(value: string, prefix: string): bool

Whether the string begins with prefix.

stdlib/std/string.lyr:68

endsWith function

pub fn endsWith(value: string, suffix: string): bool

Whether the string ends with suffix.

stdlib/std/string.lyr:71

trim function

pub fn trim(value: string): string

Without leading and trailing whitespace.

stdlib/std/string.lyr:75

toUpper function

pub fn toUpper(value: string): string

Upper-cased, ordinal — the same result everywhere, no culture involved.

stdlib/std/string.lyr:80

toLower function

pub fn toLower(value: string): string

Lower-cased, ordinal.

stdlib/std/string.lyr:83

split function

pub fn split(value: string, separator: string): string[]

The parts between occurrences of separator. An empty separator panics: "split into what" has no answer.

stdlib/std/string.lyr:89

toChars function

pub fn toChars(value: string): char[]

The characters as an array, in one O(n) pass — what for (c in s) uses.

stdlib/std/string.lyr:94

fromChars function

pub fn fromChars(chars: char[]): string

The characters joined back into one string — the inverse of toChars. Native since v1.14: one call instead of one string per character.

stdlib/std/string.lyr:99

utf8Encode function

pub fn utf8Encode(value: string): uint8[]

The string as UTF-8 bytes — the inverse of utf8Decode, and what a file or a socket actually carries.

stdlib/std/string.lyr:108

utf8Decode function

pub fn utf8Decode(bytes: uint8[]): ?string

The bytes as a string, STRICTLY: invalid UTF-8 answers null rather than a U+FFFD quietly standing in for the data — the difference to readText, whose replacement decoding is documented there.

stdlib/std/string.lyr:114

isDigit function

pub fn isDigit(c: char): bool

'0' through '9'.

stdlib/std/string.lyr:423

isAlpha function

pub fn isAlpha(c: char): bool

An ASCII letter.

stdlib/std/string.lyr:429

isAlphanumeric function

pub fn isAlphanumeric(c: char): bool

An ASCII letter or a digit.

stdlib/std/string.lyr:434

isWhitespace function

pub fn isWhitespace(c: char): bool

Space, tab, \n or \r.

stdlib/std/string.lyr:439

isUpper function

pub fn isUpper(c: char): bool

'A' through 'Z'.

stdlib/std/string.lyr:444

isLower function

pub fn isLower(c: char): bool

'a' through 'z'.

stdlib/std/string.lyr:449

charToDigit function

pub fn charToDigit(c: char): ?int

The numeric value of a digit, or null when it is not one.

?int rather than -1: a failure the caller has to handle belongs in the type.

stdlib/std/string.lyr:456

digitToChar function

pub fn digitToChar(value: int): ?char

The digit as a character, or null outside 0..9.

stdlib/std/string.lyr:464

isEmpty function

pub fn isEmpty(value: string): bool

Whether the length is zero.

stdlib/std/string.lyr:474

isBlank function

pub fn isBlank(value: string): bool

Empty or whitespace only.

stdlib/std/string.lyr:482

indexOfFrom function

pub fn indexOfFrom(value: string, needle: string, start: int): int

Searches from a position. -1 when nothing is found, as in indexOf.

stdlib/std/string.lyr:504

lastIndexOf function

pub fn lastIndexOf(value: string, needle: string): int

The LAST occurrence.

stdlib/std/string.lyr:510

count function

pub fn count(value: string, needle: string): int

How often needle occurs, WITHOUT overlap.

Overlapping occurrences are not counted: count("aaa", "aa") is 1, not 2. This matches replace.

stdlib/std/string.lyr:519

join function

pub fn join(parts: string[], separator: string): string

Joins the parts with a separator: the inverse of split. One native call — a left fold would copy the whole result once per part.

stdlib/std/string.lyr:528

splitLines function

pub fn splitLines(value: string): string[]

Splits at line breaks. Both \r\n and \n count.

stdlib/std/string.lyr:533

splitFirst function

pub fn splitFirst(value: string, separator: string): string[]

Splits at the FIRST occurrence; the rest stays whole, for key=value=more.

stdlib/std/string.lyr:539

replace function

pub fn replace(value: string, needle: string, replacement: string): string

Every non-overlapping occurrence of needle replaced. An empty needle changes nothing.

stdlib/std/string.lyr:547

replaceFirst function

pub fn replaceFirst(value: string, needle: string, replacement: string): string

The first occurrence replaced; without one the string comes back unchanged.

stdlib/std/string.lyr:553

trimStart function

pub fn trimStart(value: string): string

Without leading whitespace.

stdlib/std/string.lyr:561

trimEnd function

pub fn trimEnd(value: string): string

Without trailing whitespace.

stdlib/std/string.lyr:567

padStart function

pub fn padStart(value: string, width: int, fill: char): string

Pads at the front until width is reached. A longer string is left unchanged; truncating would lose data in a function that only formats.

stdlib/std/string.lyr:574

padEnd function

pub fn padEnd(value: string, width: int, fill: char): string

Pads at the end until width is reached. A longer string is left unchanged; truncating would lose data in a function that only formats.

stdlib/std/string.lyr:581

parseInt function

pub fn parseInt(value: string): ?int

"-42" becomes -42, anything else null.

No overflow protection: a number beyond int64 wraps rather than yielding null. Detecting it would need a division per digit.

stdlib/std/string.lyr:595

parseIntRadix function

pub fn parseIntRadix(value: string, radix: int): ?int

From a base of 2 to 36. Letters continue from a/A.

stdlib/std/string.lyr:629

parseBool function

pub fn parseBool(value: string): ?bool

Exactly "true" or "false"; anything else is null.

stdlib/std/string.lyr:674

parseFloat function

pub fn parseFloat(value: string): ?float

"3.5", "-0.25" and "42" become floating point; everything else is null.

Without exponent notation (1e9), which would need a state machine of its own.

stdlib/std/string.lyr:687

StringBuilder class

pub class StringBuilder

Builds a string piece by piece.

s = s + part in a loop is quadratic: every step copies the whole string so far. The builder collects the parts and joins them once.

The backing is a doubling string[], written by hand because this module must not import std.collections.

parts: string[]

count: int

pub static fn new(): StringBuilder

pub fn length(): int

pub mut fn append(value: string): void

pub mut fn appendLine(value: string): void

pub mut fn appendChar(value: char): void

pub fn build(): string

stdlib/std/string.lyr:751

newStringBuilder function

pub fn newStringBuilder(): StringBuilder

An empty builder.

stdlib/std/string.lyr:811