04.-functions.md

04. Functions

4.1 Implicit return by default

• Functions return their last expression value. Use that as an implicit return.

  Sqr(X:int):int =
  
       X * X # Implicit return

• If using any explicit returns, all returns in the function should be explicit.

4.2 GetX functions should be

• Getters or functions with similar semantics that may fail to return valid values should be marked <decides><transacts> and return a non-option type. The caller should handle potential failure.

  GetX()<decides><transacts>:x

• An exception is functions that need to unconditionally write to a var. Failure would roll the mutation back, so they need to use logic or option for their return type.

4.3 Prefer Extension Methods to Single Parameter Functions

• Use extension methods instead of a function with a single typed parameter.

Doing this helps Intellisense. By typing

• MyVector.Normalize() instead of Normalize(MyVector)

it can suggest names with each character of the method name you type. For example:

 (Vector:vector3).Normalize<public>():vector3

Do not:

  Normalize<public>(Vector:vector3):vector3