Returning values from `using` clauses

You can return values from using clauses by using the standard return statement. If you return a value from a using clause, Gosu considers the clause complete, and therefore calls your object’s final life-cycle management method to clean up your resources:

For disposable objects, Gosu calls the dispose method.
For closable objects, Gosu calls the close method.
For a reentrant or lock object, Gosu calls the exit method.

The following Gosu example opens a file using the Java BufferedReader class and reads lines from the file until the line matches a regular expression. If code in the while loop finds a match, it immediately returns the value and skips the rest of the code within the using clause.

uses java.io.File
uses java.io.BufferedReader
uses java.io.FileReader

function containsText(file : File, regExp : String) : boolean {
  using (var reader = new BufferedReader(new FileReader(file))) {
    var line = reader.readLine()
    while (line != null) {
      if (line.matches(regExp)) {
        return true
      }
      line = reader.readLine() // Read the next line
    }
  }
  return false
}

Returning values from using clauses

Returning values from `using` clauses