Instance(3pm)

💖 Instance(3pm) 💖

okay bestie, this one's a lil Perl module from the User Contributed Perl Documentation corner of the internet, and it's lowkey iconic in a nerdy way. sit down, grab a strawberry 🍓, let's go.

---

✨ NAME ✨

AI::DecisionTree::Instance — a C-struct wrapper for training instances 🎀

---

🌈 SYNOPSIS 🌈

use AI::DecisionTree::Instance;

my $i = new AI::DecisionTree::Instance([3,5], 7, 'this_instance');
$i->value_int(0) == 3;
$i->value_int(1) == 5;
$i->result_int == 7;

like… look at her go. three values in, three method calls out, everything checks out, slay 💅

---

🦋 DESCRIPTION 🦋

so basically this class is just a lil baby Perl wrapper wrapping a C struct, and that struct is embodying a single training instance. that's the whole personality. one instance. periodt.

the reason she exists is to reduce memory usage — and ngl she eats. in a "typical" training set with about 1000 instances, memory usage can be reduced by about a factor of 5 (from 43.7M to 8.2M in my test program). FIVE. TIMES. like, that's not a glow-up that's a whole transformation 💀✨

there's also a fairly tight loop implemented that helps speed up the train() AI::DecisionTree method by about a constant factor of 4. so she's fast and she's small. main character energy fr fr 👑

⚠️ okay important bestie: please do not consider this interface stable — the author changes it whenever they have a new need in AI::DecisionTree. so don't go building your whole life around it, she's a free spirit 🧚

---

🎀 AUTHOR 🎀

Ken Williams, ken@mathforum.org 🫶

---

⭐ SEE ALSO ⭐

• AI::DecisionTree

---

and that's the whole vibe check, bestie 💜 this page came to you courtesy of perl v5.42.3, dated 2026-08-19 — go forth and build those decision trees, no cap 🌸🦋