String

The methods of strings. The compiler forwards the string methods it does not know itself to this namespace:

"a,b".Contains(",")        // is String.Contains("a,b", ",")
string.Join(", ", parts)   // is String.Join(", ", parts)

The functions take a StringSlice (a string converts to one for free, and s[i..j] is one), so they work on parts of a string without copying; String.Trim, String.Split and String.Substring return slices as well. Copy a result with .ToString() to keep it as a string.

Strings are UTF-8. Positions and lengths are byte offsets (like s.Length and s[i]). Case conversion only handles ASCII letters.

Functions

Name	Description
IsNullOrEmpty	Whether s is empty (a null string is empty too).
Equals	Whether a and b have the same bytes (a == b).
GetHashCode	A hash code of s (FNV-1a), for Dictionary keys: equal strings have equal codes.
CompareTo	Compares a and b by their UTF-8 bytes (ordinal, no locale).
IndexOf	The position of the first occurrence of value in s at or after start.
LastIndexOf	The position of the last occurrence of the character value in s.
Contains	Whether value occurs in s.
StartsWith	Whether s starts with prefix.
EndsWith	Whether s ends with suffix.
Substring	The part of s from start to the end, as a view: s[start..].
IsSpace	Whether c is a space, a tab or a line break (\n, \r): the white space that String.Trim removes.
Trim	s without the white space at both ends (a view of s, nothing is copied).
TrimStart	s without the white space at the start (a view).
TrimEnd	s without the white space at the end (a view).
PadLeft	s filled up to width characters (bytes) with spaces on the left: "7".PadLeft(3) is " 7".
PadRight	s filled up to width characters (bytes) with spaces on the right.
ToUpper	s with the ASCII letters in upper case.
ToLower	s with the ASCII letters in lower case.
Replace	s with every occurrence of oldValue replaced by newValue.
Repeat	s repeated count times: "ab".Repeat(3) is "ababab".
Split	The parts of s between the occurrences of separator, as views of s (nothing is copied): "a,,b".Split(",") is ["a", "", "b"].
Join	The parts joined into one string, with separator between them: string.Join(", ", names).
ParseInt64	The integer in s: decimal digits with an optional + or - sign, nothing else (no spaces).
ParseInt	The integer in s: decimal digits with an optional + or - sign, nothing else (no spaces).
ParseDouble	The floating point number in s ("3.5", "-1e-3", "inf", …; the C library’s strtod, without spaces around it).

IsNullOrEmpty

bool IsNullOrEmpty(StringSlice s)

Whether s is empty (a null string is empty too).

Equals

bool Equals(string a, string b)

Whether a and b have the same bytes (a == b).

bool Equals(StringSlice a, StringSlice b)

Whether a and b have the same bytes (a == b).

GetHashCode

int GetHashCode(string s)

A hash code of s (FNV-1a), for Dictionary keys: equal strings have equal codes.

int GetHashCode(StringSlice s)

A hash code of s (FNV-1a): the same as for a string with the same text.

CompareTo

int CompareTo(string a, string b)

Compares a and b by their UTF-8 bytes (ordinal, no locale).

Returns -1 if a comes first, 0 if they are equal, 1 if b comes first.

int CompareTo(StringSlice a, StringSlice b)

Compares a and b by their UTF-8 bytes (ordinal, no locale), like strings.

Returns -1 if a comes first, 0 if they are equal, 1 if b comes first.

IndexOf

int IndexOf(StringSlice s, StringSlice value, int start)

The position of the first occurrence of value in s at or after start.

Returns -1 if there is none.

int IndexOf(StringSlice s, StringSlice value)

The position of the first occurrence of value in s.

Returns -1 if there is none.

int IndexOf(StringSlice s, char value)

The position of the first occurrence of the character value in s.

Returns -1 if there is none.

int IndexOf(StringSlice s, char value, int start)

The position of the first occurrence of the character value in s at or after start.

Returns -1 if there is none.

LastIndexOf

int LastIndexOf(StringSlice s, char value)

The position of the last occurrence of the character value in s.

Returns -1 if there is none.

Contains

bool Contains(StringSlice s, StringSlice value)

Whether value occurs in s.

bool Contains(StringSlice s, char value)

Whether the character value occurs in s.

StartsWith

bool StartsWith(StringSlice s, StringSlice prefix)

Whether s starts with prefix.

EndsWith

bool EndsWith(StringSlice s, StringSlice suffix)

Whether s ends with suffix.

Substring

StringSlice Substring(StringSlice s, int start)

The part of s from start to the end, as a view: s[start..]. (string.Substring of a string is built in and copies.)

Since 0.06

StringSlice Substring(StringSlice s, int start, int count)

The count bytes of s from start, as a view: s[start..start + count].

Since 0.06

IsSpace

bool IsSpace(char c)

Whether c is a space, a tab or a line break (\n, \r): the white space that String.Trim removes.

Trim

StringSlice Trim(StringSlice s)

s without the white space at both ends (a view of s, nothing is copied).

StringSlice Trim(StringSlice s, char c)

s without the character c at both ends (a view): "--a-b--".Trim('-') is "a-b".

Since 0.32

TrimStart

StringSlice TrimStart(StringSlice s)

s without the white space at the start (a view).

Since 0.04

StringSlice TrimStart(StringSlice s, char c)

s without the character c at the start (a view): "007".TrimStart('0') is "7".

Since 0.04

TrimEnd

StringSlice TrimEnd(StringSlice s)

s without the white space at the end (a view).

Since 0.04

StringSlice TrimEnd(StringSlice s, char c)

s without the character c at the end (a view): "1.500".TrimEnd('0') is "1.5".

Since 0.04

PadLeft

string PadLeft(StringSlice s, int width)

s filled up to width characters (bytes) with spaces on the left: "7".PadLeft(3) is " 7".

Since 0.04

string PadLeft(StringSlice s, int width, char fill)

s filled up to width characters (bytes) with fill on the left: "7".PadLeft(3, '0') is "007".

Since 0.04

PadRight

string PadRight(StringSlice s, int width)

s filled up to width characters (bytes) with spaces on the right.

Since 0.04

string PadRight(StringSlice s, int width, char fill)

s filled up to width characters (bytes) with fill on the right.

Since 0.04

ToUpper

string ToUpper(StringSlice s)

s with the ASCII letters in upper case.

ToLower

string ToLower(StringSlice s)

s with the ASCII letters in lower case.

Replace

string Replace(StringSlice s, StringSlice oldValue, StringSlice newValue)

s with every occurrence of oldValue replaced by newValue.

Returns s unchanged if oldValue is empty.

Repeat

string Repeat(StringSlice s, int count)

s repeated count times: "ab".Repeat(3) is "ababab".

Split

StringSlice[] Split(StringSlice s, StringSlice separator)

The parts of s between the occurrences of separator, as views of s (nothing is copied): "a,,b".Split(",") is ["a", "", "b"].

StringSlice[] Split(StringSlice s, char separator)

The parts of s between the occurrences of the character separator, as views of s.

Join

string Join(StringSlice separator, string[] parts)

The parts joined into one string, with separator between them: string.Join(", ", names).

string Join(StringSlice separator, StringSlice[] parts)

The parts (e.g. the result of String.Split) joined into one string, with separator between them.

ParseInt64

ParseError<int64> ParseInt64(StringSlice s)

The integer in s: decimal digits with an optional + or - sign, nothing else (no spaces).

Errors

• ParseError.Invalid: s is not an integer.
• ParseError.OutOfRange: the number does not fit into an int64.

ParseInt

ParseError<int> ParseInt(StringSlice s)

The integer in s: decimal digits with an optional + or - sign, nothing else (no spaces).

Errors

• ParseError.Invalid: s is not an integer.
• ParseError.OutOfRange: the number does not fit into an int.

ParseDouble

ParseError<double> ParseDouble(StringSlice s)

The floating point number in s ("3.5", "-1e-3", "inf", …; the C library’s strtod, without spaces around it).

Errors

• ParseError.Invalid: s is not a number.