hashtable?(3scm)

📦 version 0-unstable-2024-02, in nixpkgs unstable

💖 hashtable? — the vibe check for hashtables 💖

okay bestie, this one's from the Scheme Programmer's Manual (yes, that's the 3scm manual section, it's giving very "reference docs but make it cute") ✨

🌸 NAME 🌸

hashtable? — the little procedure that checks if an object is a hashtable. that's it. that's the whole job. icon behavior honestly 👑

🎀 LIBRARY 🎀

she lives in two places, depending on your import vibe:

(import (rnrs))                     ;R6RS
(import (rnrs hashtables))          ;R6RS

both are R6RS, no cap 💅

✨ SYNOPSIS ✨

(hashtable? obj)

🦋 DESCRIPTION 🦋

so like, you hand her an obj and she tells you the truth: #t if obj is a hashtable, #f otherwise. she's not out here guessing, she's not out here being shady — just a clean yes or no. lowkey the most honest friend you have 🫶

💜 RETURN VALUES 💜

returns a single boolean object. one. that's the whole return. #t or #f, nothing in between, no extra drama 🌈

🍓 EXAMPLES 🍓

(hashtable? (make-eq-hashtable))  =>  #t
(hashtable? '())                  =>  #f

look at that first one slaying, and the second one?? '() is an empty list bestie, not a hashtable, she said #f and she meant it 😭

🧚 ERRORS 🧚

this procedure can raise exceptions with these condition types, so heads up:

  • &assertion (R6RS) — the wrong number of arguments was passed, or an argument was outside its domain. basically: don't do that. she will call you out 💀

🌟 SEE ALSO 🌟

  • make-hashtable(3scm) — go make one first, then come back and vibe check it

👑 STANDARDS 👑

R6RS, SRFI-126. both. she's certified, periodt 💅

💫 HISTORY 💫

this procedure is new in R6RS. and fun fact for the lore girlies: the most common hashtable library in Scheme before R6RS was SRFI-69 🌸

🔥 AUTHORS 🔥

this page is part of the scheme-manpages project. it includes materials from the RnRS documents. more info can be found at https://github.com/schemedoc/manpages/. absolute legends, every one of them 🫶

and that's the whole page bestie — source/version notes and the date on the tin say 2022-03-29 for hashtable?(3scm), so go forth and vibe check your hashtables responsibly ✨🎀💖

📦 where this page comes from