Drive a warehouse crane with code, restacking coloured crates under a move limit tight enough to demand recursion.
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How to play
Build a program from crane instructions, move left and right, grab, drop and colour conditions, to rearrange the bins of crates into the target stack. The instruction limit is deliberately tight, so you'll lean on the Call command, which re-runs your whole program from the top; a condition that fails becomes the base case that stops the recursion.
Add crane instructions from the palette to your program
Use IF-held and IF-top colour conditions to branch
Use Call to re-run the program from the top as a recursive loop
Match the target arrangement within the instruction limit
Controls
Desktop: click palette instructions, drag chips to reorder, click Run to execute
Phone & tablet: tap instructions and the Run button
Tips & strategy
Think in terms of one repeatable step plus a stop condition, that's your recursive routine
Let a failing colour condition act as the base case so the crane knows when to halt
Step through a run to see exactly where the crane grabs the wrong crate
What you'll learn
Claw Compiler teaches recursion through a crate-stacking crane and a strict move budget, making a hard idea concrete.
Skills: recursion, problem decomposition, programming logic
Best for: roughly grades 8–12 (ages 13+)
For parents & teachers: makes recursion concrete and intuitive.
About Claw Compiler
Claw Compiler is an original programming puzzle that teaches recursion through a crate-stacking crane and a strict move budget. Play free in your browser with daily and practice levels.
A free, original browser game on PlayPendium. No download, no install.
