We use label as a fakeyword for providing parameter labels in source languages that do not support them inherently.

Symbol Usage Notes
type label<T extends string> = undefined Label fakeyword definition Type parameter is used for the parameter name and only accepts string literal

Parameter labelling is used in target contexts like Swift, where the label may differ from the name used for the parameter inside the function body (implementation).

Using label also allows the programmer to specify names that would otherwise be illegal tokens in the source language, such as for.

Inference

You do not need to provide argument labels at call sites. Sempiler will infer them from the matching function declaration and they will be emitted only if required.