Logic

Verse uses logic as the type for Boolean values, which means logic only has two possible values: true and false.

Both true and false are logic literals when you use them in Verse code.

The following is an example of how to create a logic variable named TargetLocked, initialized with the logic literal false:

var TargetLocked : logic = false

Logic Operations

The logic type supports query operations and comparison operations.

Query

Query expressions use the operator ? (query) and check if a logic value is true. Otherwise, the expression fails if the logic value is false.

# Determine whether to show the target-locked icon if a target is locked
if (TargetLocked?):
    ShowTargetLockedIcon()

For more on query operations, see Operators.

Comparison

For comparison operations, you can use the failable operator = to test if two logic values are equal, and the failable operator <> to test for inequality.

For example, the sample code below will make an "unavailable action" icon appear if the player has equipped a weapon but doesn't have a target, or has a target but no weapon. This can be expressed by comparing logic values that represent the two factors.

• If both are false, you won't see the icon because the player isn't trying to attack.

• If both are true, you won't see the icon because the player is able to attack.

  Verse

  # Initialize logic variables for demonstration purposes.
        var TargetLocked : logic = false
        var WeaponEquipped : logic = true
  			
        # Determine whether or not the "unavailable action" icon is appropriate.
        if (WeaponEquipped <> TargetLocked):
            # The icon should show up, because the player appears to be trying to
            # attack, but is missing either a weapon or a target.
            ShowUnavailableIcon()

  Copy full snippet(9 lines long)

For more on comparison operations, see Operators.

Convert Failable Expression to Logic

You can cast a failable expression to a logic type using logic{failable-expression}, where failable-expression is an expression that can fail.

In the following example, the failable expression GetRandomInt(0, MineFrequency) <> 0 is converted to the logic value false if the random integer is 0 and true otherwise.

IsMined := logic{GetRandomInt(0, MineFrequency) <> 0}

Standard Library

The standard library provides functions to help with creating and using logic values. Refer to the Verse API Reference for more details on these functions.

Persistable Type

Logic values are persistable, which means that you can use them in your module-scoped weak_map variables and have their values persist across game sessions. For more details on persistence in Verse, check out Using Persistable Data in Verse.