fixnums(7scm)

💅 fixnums(7scm) — the girl's guide to fixnum arithmetic 🎀

Okay bestie, so this one is from the Scheme Programmer's Manual, and it's literally all about fixnums. Let's get into it ✨

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🌸 NAME 🌸

fixnums — Fixnum arithmetic. That's it, that's the vibe. 💖

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📚 LIBRARY 📚

Import it like this, exactly like this, no cap:

(import (rnrs arithmetic fixnums))

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✨ DESCRIPTION ✨

So here's the tea. Every implementation must define its fixnum range as a closed interval:

[−2^(w−1), 2^(w−1)−1]

where w is a (mathematical) integer and w ≥ 24. Yes, twenty-four. Minimum. No exceptions, periodt. 👑

Every mathematical integer that lives inside an implementation's fixnum range must correspond to an exact integer object that's representable within that implementation. And a fixnum? It's an exact integer object whose value lies within this fixnum range. Simple as that. 🦋

Now, the important bit — fixnum operations do integer arithmetic on their fixnum arguments, but they raise an exception with condition type &implementation-restriction if the result is not a fixnum. So like… if your math escapes the range, it's not going quietly. It's gonna throw hands. 😭

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🧚 IMPLEMENTATION NOTES 🧚

🖤 GNU Guile

Guile runs generic arithmetic faster than fixnums. Iconic, honestly. So if your numbers are of a certain width (e.g. 32-bit), they should be truncated with bitwise-and. That's the move. 💅

🩷 IronScheme

IronScheme stores fixnums on the heap. So remember: do not use eq?, assq or memq on fixnums. 🙈 (And ngl, this applies to Scheme as such, not just IronScheme — so it's a whole-language thing, bestie.)

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🌈 STANDARDS 🌈

R6RS. That's the one. ⭐

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👀 SEE ALSO 👀

• fixnum-width(3scm) — go read it, iykyk 💜

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🫶 AUTHORS 🫶

This page is part of the scheme-manpages project. It includes materials from the RnRS documents. More information can be found at https://github.com/schemedoc/manpages/. ✨

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This page is dated 2020-04-18 and comes from the fixnums(7scm) entry in the Scheme Programmer's Manual, bestie — slay, go write some arithmetic 💖🌸🦋