The Fortress Language Specification - CiteSeerX

ead(fileName) =
try
readFile(fileName)
catch e
IOException ⇒throw Error(“This code can’t handle IOExceptions”, e)
end
where the message and chain fields of Error are set to “This code can’t handle IOExceptions” and
IOException respectively.
By default, a forbid clause in a try expression throws a new ForbiddenException by chaining the exception
thrown by the try block in the try expression that is a subtype of the exception type listed in the forbid clause.
For example, the following read function:
read(fileName) =
try
readFile(fileName)
forbid IOException
end
is equivalent to:
read(fileName) =
try
readFile(fileName)
catch e
IOException ⇒throw ForbiddenException(e)
end
where the chain of ForbiddenException is set to IOException.
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