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Bytevectors

Bytevectors are sequences of unsigned 8-bit integers (0–255), useful for binary data and string encoding.

Literal Syntax

sema
#u8(1 2 3)       ; bytevector literal
#u8()            ; empty bytevector
#u8(255 0 128)   ; arbitrary byte values

Construction

bytevector

Create a bytevector from byte values.

sema
(bytevector 1 2 3)       ; => #u8(1 2 3)
(bytevector)             ; => #u8()

bytevector/new

Create a bytevector of a given length, optionally filled with a value.

sema
(bytevector/new 4)       ; => #u8(0 0 0 0)
(bytevector/new 3 255)   ; => #u8(255 255 255)

Access & Mutation

bytevector/length

Return the length of a bytevector.

sema
(bytevector/length #u8(1 2 3))   ; => 3
(bytevector/length #u8())        ; => 0

bytevector/ref

Return the byte at a given index.

sema
(bytevector/ref #u8(10 20 30) 1)   ; => 20
(bytevector/ref #u8(10 20 30) 0)   ; => 10

bytevector/set!

Set the byte at a given index. Uses copy-on-write — the original bytevector is unchanged.

sema
(bytevector/set! #u8(1 2 3) 0 9)   ; => #u8(9 2 3)

Copy & Append

bytevector/copy

Copy a slice of a bytevector. (bytevector/copy bv start end).

sema
(bytevector/copy #u8(1 2 3 4 5) 1 3)   ; => #u8(2 3)

bytevector/append

Concatenate bytevectors.

sema
(bytevector/append #u8(1 2) #u8(3 4))   ; => #u8(1 2 3 4)

List Conversion

bytevector/to-list

Convert a bytevector to a list of integers.

sema
(bytevector/to-list #u8(65 66))   ; => (65 66)

list/to-bytevector

Convert a list of integers to a bytevector.

sema
(list/to-bytevector '(1 2 3))   ; => #u8(1 2 3)

String Conversion

utf8/to-string

Decode a bytevector as a UTF-8 string.

sema
(utf8/to-string #u8(104 105))       ; => "hi"
(utf8/to-string #u8(72 101 108))    ; => "Hel"

string/to-utf8

Encode a string as a UTF-8 bytevector.

sema
(string/to-utf8 "hi")     ; => #u8(104 105)
(string/to-utf8 "Hello")  ; => #u8(72 101 108 108 111)