Math::E...timizer(3)

💖 Math::E...timizer(3) — bestie edition 💖

okay so this is the Math::Expression::Evaluator::Optimizer page, from the User Contributed Perl Documentation crew, and she is here to make your ASTs faster. sit down, hydrate, let's go 🫶

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✨ NAME ✨

Math::Expression::Evaluator::Optimizer — literally just here to Optimize Math::Expression::Evaluator ASTs 💅

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✨ SYNOPSIS ✨

here's the vibe, copy-paste ready, no cap:

use Math::Expression::Evaluator;
my $m = Math::Expression::Evaluator->new("2 + 4*f");
$m->optimize();
for (0..100){
    print $m->val({f => $_}), "\n";
}

like… you build it, you optimize() it, you run it a hundred times. iconic behaviour honestly 😌

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✨ DESCRIPTION ✨

so Math::Expression::Evaluator::Optimizer does some simple optimizations on the abstract syntax tree that comes out of Math::Expression::Evaluator. that's it. that's the job. she's not doing anything wild, she's just tidying up 🧚

🚨 bestie listen: you should NOT use this module directly. interface it via Math::Expression::Evaluator instead. do not text her directly, go through the group chat, iykyk 🙈

and here's the menu of optimizations she's serving:

• Constant sub expressions — "variable + 3 * 4" gets simplfied to "variable + 12". the math is mathing before you even run it, we love to see it 💖
• Joining of constants in mixed constant/variable expressions — "2 + var + 3" becomes "var + 5". and before you ask: it Works only with sums and products. BUT — and this is the fun part — internally a "2 - 3 + x" is represented as "2 + (-3) + x", so it actually works with differences and divisions as well. she's sneaky like that 😏✨
• Flattening of nested sub expression — "a * (3 * b)" gets flattened into "a * 3 * b". currently this is done before any other optimization and not repeated. one and done, main character energy, periodt 💅

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✨ PERFORMANCE CONSIDERATIONS ✨

okay this is the part where i hold your hand, because the truth is a little 😭

optimize() currently takes two full loops through the AST, copying and recreating it. so if you only call val() once, calling optimize() is in fact a performance loss. like, you made it slower. you did that. ngl that's rough 💀

but! if the expression is optimizable, and you execute it $n times, you usually have a net gain over unoptimized execution if $n > 15 🔥

of course that value depends on the complexity of the expression, and how well it can be reduced by the implemented optimizations. it's giving "it depends" and honestly that's just the truth 🦋

🌸 your best is to always benchmark what you do. seriously. no guessing, no vibes-based perf claims, just measure it.

and here's the tea you actually want: most of the time, the compiled version returned by "->compiled" is much faster than the optimized (and not compiled) form. so like… maybe go there instead? just a thought 👑

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and that's the whole page, bestie!! 🌈💜 she's from perl v5.42.0, dated 2025-07-25, and honestly? iconic of her. go forth and optimize responsibly, mwah 💋🎀