AL gives no short-circuit (lazy) evaluation guarantee for and/or/xor —
neither the AL operators nor the boolean operators documentation defines a
lazy evaluation order. LLMs trained on C#, JavaScript, or SQL assume the
left operand guards the right, which produces conditions where a guard
does not protect an unsafe subscript or a field read after a failed Get,
and where an expensive operand is paid on every path.
Adds community/knowledge/performance/boolean-operators-do-not-short-circuit.md
with good/bad AL companions. The guidance prefers nested if when one operand
depends on another, while keeping and/or legitimate for operands that are
independently safe and cheap, so a reviewer does not flag harmless bound
checks. This is the first article in a community performance domain; the
Microsoft performance review leaf skill already sources candidates by domain
across every enabled layer, so no skill change is needed to reach it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
