bytevector-copy(3scm)

💖 NAME 💖

bytevector-copy — bestie, it copies a bytevector, that's literally it

So this page lives in the Scheme Programmer's Manual (iconic company, no notes), and it's here to walk you through the one job this procedure has: duplicating bytes. Slay.

🌸 LIBRARY 🌸

ok so here's where you grab it from — pick your fave, they all work:

(import (rnrs))                     ;R6RS
(import (rnrs bytevectors))         ;R6RS
(import (scheme base))              ;R7RS

✨ SYNOPSIS ✨

(bytevector-copy bytevector)
(bytevector-copy bytevector start)      ;R7RS
(bytevector-copy bytevector start end)  ;R7RS

🦋 DESCRIPTION 🦋

It hands you back a freshly allocated bytevector 🎀 filled with the bytes from bytevector that live between start (inclusive, she's invited) and end (exclusive, she's not). Classic half-open interval behaviour, we love to see it.

And if you're feeling lazy (valid), the defaults got you:

• start defaults to 0
• end defaults to the length of the input

🫶 RETURN VALUES 🫶

You get a bytevector back, and its length is end - start. Math! But make it bytes. 💅

🔥 EXAMPLES 🔥

(define a #u8(1 2 3 4 5))
(bytevector-copy a 2 4))
   => #u8(3 4)

Look at her go. Grabbed index 2 and 3, dipped before 4. Main character energy fr fr.

😭 COMPATIBILITY 😭

Heads up bestie: the R6RS version of this procedure only has the first argument. So if you're passing start or end around in R6RS land, that's not gonna fly. 🫠

💀 ERRORS 💀

Yes, it can raise exceptions with the following condition types:

• &assertion (R6RS) — the wrong number of arguments was passed, or an argument was outside its domain.
• R7RS — the assertions described above are errors. Implementations may signal an error, extend the procedure's domain of definition to include such arguments, or fail catastrophically. 😭 Not "fail catastrophically" as a lil joke either — that's the actual wording. Stay safe out there.

👑 SEE ALSO 👑

bytevector-copy!(3scm) — the destructive sibling, go say hi 💜

🌈 STANDARDS 🌈

R6RS, R7RS — certified, both of them, no cap ⭐

🧚 AUTHORS 🧚

This page is part of the scheme-manpages project. It includes materials from the RnRS documents. More info lives at https://github.com/schemedoc/manpages/ — go check it out 🍓

and that's the whole page, bestie!! brought to you by the scheme-manpages source, dated 2021-02-20, from bytevector-copy(3scm) — mwah 💋✨🎀