Enum Type

An Enum value selects one option from a fixed, named set of choices. Unlike Cell Type or Log Tag Type, which each have exactly one set of options shared by every port of that type, Enum Type is backed by a registry of separately named enum definitions — such as ComputingTargetEnum or EnvironmentKeyEnum — each one a list of dot-constant/label pairs. A given port declares which named definition it uses, so two different Enum Type ports can accept entirely different sets of options depending on which definition they reference.

Some examples, spanning several unrelated functors:

• Transform Map's resamplingMethod offers fourteen resampling algorithms: .nearest (0, “Nearest”), .bilinear (1, “Bilinear”), .cubic (2, “Cubic”), .spline (3, “Cubic Spline”), .lanzo (4, “Lanzos”), .average (5, “Average”), .mode (6, “Mode”), .maximum (7, “Maximum”), .minimum (8, “Minimum”), .median (9, “Median”), .1quartile (10, “1st Quartile”), .3quartile (11, “3rd Quartile”), .rms (12, “Root Mean Square”), and .sum (13, “Weighted Sum”).
• Load Map's storageMode offers .default (0, “Default”), .preferMemory (1, “Prefer Memory”), .preferDisk (2, “Prefer Disk”), and .loadAsSparse (3, “Load As Sparse”) — this is the same storageMode mechanism described on the Map Type page's Storage section, confirmed here to be an ordinary Enum Type port rather than a separate mechanism of its own.
• Get Environment Value's key uses the EnvironmentKeyEnum definition, offering ten options identifying which environment path or fact to retrieve — .temp, .modelDir, .modelTempFolder, .userFolder, .userSubmodelFolder, .storeSubmodelFolder, .appFolder, .appVersion, .baseOS, and .osExeExtension. Unlike the examples above, this port is required and has no default — every call must choose one explicitly.
• Execution Policy's computingTarget uses the ComputingTargetEnum definition: .default (0, “Default”), .processorsOnly (1, “Processors Only”), and .acceleratorDevicesOnly (2, “Accelerator Devices Only”).

Like any other type, an Enum Type port can also be nullable: Run Remotely's networkErrorBehavior offers .abortExecution (0) and .runLocally (1), but defaults to .none rather than to either option, falling back to the application's own setting when left unspecified.

The enum editor presents a dropdown listing the port's own named enum definition. This is the same dropdown experience light enum recreates for the integer-family value types — light enum exists precisely for ports that need this presentation without actually being Enum Type underneath.

An Enum constant uses the same dot-constant syntax as any other type — see Constants — but which dot-constants a given port accepts depends entirely on the named enum definition that port references, not on any single, universal list:

elevation := LoadMap {
    filename = "c:/data/elevation.tif",
    storageMode = .preferMemory
};

• Converted from: Integer Value Type, Non Negative Integer Value Type, Positive Integer Value Type, and Real Value Type — the number selects the option whose index matches it.

• Converted to: None.

See Type System for the complete conversion reference across all types.