Guarded Selection

CS 3304: Comparative Languages

Control Structures

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    if <boolean> -> <statement>
    [] <boolean> -> <statement>
          ...
    [] <boolean> -> <statement>
    fi

Semantics: when this construct is reached,
- Evaluate all boolean expressions
- If more than one are true, choose one nondeterministically
- If none are true, it is a runtime error

Idea: if the order of evaluation is not important, the program should not specify one