Mekanism

Mekanism CraftTweaker support has been integrated directly into Mekanism now (link)

Mekanism adds bracket-handler support to define gas – a special material state differing from forge liquids

<gas:oxygen>
<gas:water> *

*Noting that <gas:water> is different from <liquid:water>

Example

import mod.mekanism.gas.IGasStack;

var oxygen = <gas:oxygen>.withAmount(500) as IGasStack;
var oxygen2 = <gas:oxygen> * 500;

ZenGetters

Like LiquidStacks, IGasStacks also support some special ZenGetters.
You call the ZenGetters using gas.Getter (E.g. <gas:water>.name)

ZenGetter Description Return Type
definition Returns the gas’ definition IGasDefinition
NAME Returns the gas’ name String
displayName Returns the gas’ displayName String
amount Returns the gas’ amount in millibuckets int

Setting the Object’s Amount

You can set the Object’s amount (gas volume in Millibuckets) in two ways, which both do exactly the same:

var gas_amount_multiply = <gas:water> * 500;
var gas_amount_zenMethod = <gas:water>.withAmount(500);

IGasDefinition

An IGasDefinition object contains information on a gas.
You can get such an object using gasStack.definition (check the table above)

ZenGetter Description Return Type
NAME Returns the referred gas’ name String
displayName Returns the referred gas’ display name String

You can multiply a gasDefinition to return a new IGasStack with the given amount in millibuckets:

var gas_definition = <gas:water>.definition;
var gas_bucket = gas_definition * 1000;