Anything computed inside a loop is multiplied by its length. Compiling a regular expression, reading a config value or recalculating a constant on every pass is pure waste.
The fix you can use today
Move values that do not change between iterations above the loop.
Compile patterns and look up settings once.
Cache the result of an expensive call when the inputs repeat.
GreenCode researchers list repeated work inside loops as an energy waste to fix.
Tools that help
GreenCode Constitution skill (GreenCode researchers): open-source energy principles and a catalogue of 37 energy anti-patterns that an AI coding agent can follow to find and fix waste like this
Creedengo (formerly ecoCode): static analysis rules that flag energy code smells in Java, Python, PHP, JavaScript, C# and Rust
How GreenCode helps
GreenCode helps tackle this by rewriting flagged code one piece at a time. It writes any missing tests first, and returns every change for a person to approve. More on this.
