Code Positivity

This page provides some insights into what it means to try and write code in a positive way, with the least negation as possible.

Overview

Code negation is (usually) using not (in SQF/SQS) or ! (in both SQF/SQS and Enforce Script; all in all, it is about searching for the opposite of what one wants. Examples:

SQF	Enforce Script
if (not alive player) then { hint "you are dead"; } else { hint "you are alive"; };	if (value < minValue) { Print("Value is invalid"); } else { Print("Value is valid"); }

Research has shown that negation in general (not just in code but also in reading, teaching etc) makes processing sentences more difficult for the human brain, making its message less impactful (although not in all cases).

Examples

Do	Don't
// this is called Early Return / Bouncer pattern if (isNull _control1) exitWith {}; if (isNull _control2) exitWith {}; if (isNull _control3) exitWith {}; // do something	if (not isNull _control1) then { if (not isNull _control2) then { if (not isNull _control3) then { // finally do something // <- this is called Hadouken code style as per the shape drawn by the brackets }; }; };
// whenever possible without rewriting everything or doubling the methods, of course if (unit.IsAlive() && unit.IsInjured()) DoHealThing(); // alternatively if (unit.IsDead()) DoDeathThing(); else if (unit.IsPerfectHealth()) DoPerfectThing(); else // injured DoHealThing();	// sometimes, only negative methods are available if (!unit.IsPerfectHealth() && !unit.IsDead()) DoHealThing();

Counter Examples

As most if not all rules of development, this rule is a rule of thumb that is not to be enforced at all cost.

Don't	Do
if (isNull _control) then { } else { systemChat "the control exists"; }; // or, even more convoluted and less performance-friendly if (str _control find "NULL" == -1) then { systemChat "the control exists"; };	if (not isNull _control) then // neater { systemChat "the control exists"; };
if (m_aElements.Count() > 0) Print("There are elements!"); // note that in some cases, storing the count in a variable // saves further calculations in below code	if (!m_aElements.IsEmpty()) Print("There are elements!");

See Also

• Code Optimisation
• Mission Optimisation
• Multiplayer Scripting