Results define the outputs of some declaration when it is called. Here is an example:
Here is a breakdown of the syntax:
- The name of the result (here
result). This can be any combination of upper- and lowercase letters, underscores, and numbers, as long as it does not start with a number. However, we suggest to use
lowerCamelCasefor the names of parameters.
- A colon.
- The type of the parameter (here
Let us now look at a full example of a segment called
doSomething with two results:
The interesting part is the list of results, which uses the following syntactic elements:
- An arrow
- An opening parenthesis.
- A list of results, the syntax is as described above. They are separated by commas. A trailing commas is permitted.
- A closing parenthesis.
Shorthand Version: Single Result¶
In case that the callable produces only a single result, we can omit the parentheses. The following two declarations are, hence, equivalent:
Shorthand Version: No Results¶
In case that the callable produces no results, we can usually omit the entire results list. The following two declarations are, hence equivalent:
The notable exception are callable types, where the result list must always be specified even when it is empty.
Corresponding Python Code¶
Note: This section is only relevant if you are interested in the stub language.
Results must be ordered the same way in Python as they are in Safe-DS. Moreover, the Safe-DS type of a result should capture the possible values of this result accurately. Ideally, the Python result should also have a matching type hint.
Since Python results do not have a name, the names of Safe-DS results can be arbitrary. Naturally, a name should be chosen that captures the purpose of the result.