std / strings

strings

import "std:strings"

Provides string manipulation functions. Functions are organized by allocation behavior: zero-alloc functions return views into input strings, Builder functions write to a Builder for explicit memory ownership, and Split functions return list[string] arrays where the caller frees the array. Case conversion is ASCII-only.

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Index

Types IsSpace IsDigit IsLetter IsUpper IsLower ToLowerByte ToUpperByte ToLowerRune ToUpperRune Compare EqualFold Contains ContainsByte ContainsAny HasPrefix HasSuffix Index IndexByte IndexAny LastIndex LastIndexByte Count TrimSpace TrimPrefix TrimSuffix Trim TrimLeft TrimRight Cut CutPrefix CutSuffix Split SplitN Fields NewBuilder NewBuilderSize Write WriteByte WriteString WriteRune Len Cap Reset String Bytes Free ToLower ToUpper Repeat Join Replace ReplaceAll

Types

# 
type Builder list[byte]

Provides efficient string construction. Builder is a type alias for list[byte] that the caller owns.

Character Classification (Zero-Alloc)

# 
func IsSpace(b byte) bool

Returns true if b is ASCII whitespace.

# 
func IsDigit(b byte) bool

Returns true if b is an ASCII digit (0-9).

# 
func IsLetter(b byte) bool

Returns true if b is an ASCII letter.

# 
func IsUpper(b byte) bool

Returns true if b is an ASCII uppercase letter.

# 
func IsLower(b byte) bool

Returns true if b is an ASCII lowercase letter.

Character Conversion (Zero-Alloc)

# 
func ToLowerByte(b byte) byte

Converts an ASCII uppercase letter to lowercase.

# 
func ToUpperByte(b byte) byte

Converts an ASCII lowercase letter to uppercase.

# 
func ToLowerRune(r rune) rune

Converts an ASCII uppercase letter (as rune) to lowercase.

# 
func ToUpperRune(r rune) rune

Converts an ASCII lowercase letter (as rune) to uppercase.

Comparison (Zero-Alloc)

# 
func Compare(a, b string) int

Returns -1, 0, or 1 for lexicographic comparison.

# 
func EqualFold(a, b string) bool

Reports whether a and b are equal under ASCII case-folding.

# 
func Contains(s, substr string) bool

Reports whether substr is within s.

# 
func ContainsByte(s string, b byte) bool

Reports whether b is within s.

# 
func ContainsAny(s, chars string) bool

Reports whether any character in chars is within s.

# 
func HasPrefix(s, prefix string) bool

Reports whether s starts with prefix.

# 
func HasSuffix(s, suffix string) bool

Reports whether s ends with suffix.

# 
func Index(s, substr string) int

Returns the index of the first instance of substr, or -1.

# 
func IndexByte(s string, b byte) int

Returns the index of the first instance of b, or -1.

# 
func IndexAny(s, chars string) int

Returns the index of the first instance of any char in chars, or -1.

# 
func LastIndex(s, substr string) int

Returns the index of the last instance of substr, or -1.

# 
func LastIndexByte(s string, b byte) int

Returns the index of the last instance of b, or -1.

# 
func Count(s, substr string) int

Returns the number of non-overlapping instances of substr in s.

Trimming (Zero-Alloc, return views)

# 
func TrimSpace(s string) string

Returns s with leading and trailing ASCII whitespace removed.

# 
func TrimPrefix(s, prefix string) string

Returns s without the leading prefix.

# 
func TrimSuffix(s, suffix string) string

Returns s without the trailing suffix.

# 
func Trim(s, cutset string) string

Returns s with leading and trailing characters in cutset removed.

# 
func TrimLeft(s, cutset string) string

Returns s with leading characters in cutset removed.

# 
func TrimRight(s, cutset string) string

Returns s with trailing characters in cutset removed.

Cutting (Zero-Alloc, return views)

# 
func Cut(s, sep string) (string, string, bool)

Slices s around the first instance of sep.

# 
func CutPrefix(s, prefix string) (string, bool)

Returns s without the leading prefix and whether it was found.

# 
func CutSuffix(s, suffix string) (string, bool)

Returns s without the trailing suffix and whether it was found.

Splitting (Caller frees dynamic array)

# 
func Split(s, sep string) list[string]

Slices s into all substrings separated by sep.

# 
func SplitN(s, sep string, n int) list[string]

Slices s into at most n substrings separated by sep.

# 
func Fields(s string) list[string]

Splits s around whitespace into a dynamic array.

Builder Core

# 
func NewBuilder() Builder

Returns a new Builder with default capacity.

# 
func NewBuilderSize(capacity int) Builder

Returns a new Builder with the specified initial capacity.

# 
func Write(b Builder, data []byte) int

Appends data to the Builder's buffer.

# 
func WriteByte(b Builder, c byte)

Appends byte c to the Builder's buffer.

# 
func WriteString(b Builder, s string) int

Appends string s to the Builder's buffer.

# 
func WriteRune(b Builder, r rune) int

Appends the UTF-8 encoding of rune r.

# 
func Len(b Builder) int

Returns the number of bytes in the buffer.

# 
func Cap(b Builder) int

Returns the capacity of the buffer.

# 
func Reset(b Builder)

Resets the Builder to empty, retaining the buffer.

# 
func String(b Builder) string

Returns the accumulated string (view into buffer).

# 
func Bytes(b Builder) []byte

Returns the accumulated bytes as a slice.

# 
func Free(b Builder)

Frees the Builder's internal buffer.

Builder String Construction

# 
func ToLower(b Builder, s string)

Writes the ASCII lowercase of s to the Builder.

# 
func ToUpper(b Builder, s string)

Writes the ASCII uppercase of s to the Builder.

# 
func Repeat(b Builder, s string, count int)

Writes s repeated count times to the Builder.

# 
func Join(b Builder, parts []string, sep string)

Writes parts joined by sep to the Builder.

# 
func Replace(b Builder, s, old, repl string, n int)

Writes s with up to n replacements of old with repl.

# 
func ReplaceAll(b Builder, s, old, repl string)

Writes s with all occurrences of old replaced by repl.