The Fortress Language Specification - CiteSeerX

component HelloWorld
export Executable
run(args) = print “Hello, world!”
end
We can compile this program, by issuing the command “fortress compile” on it:
fortress compile HelloWorld.fss
As a result of this command, a component named “HelloWorld” is stored in the resident fortress. The name
of this component is provided by the enclosing component declaration surrounding the code. If there is no
enclosing component declaration, then the contents of the file are understood to belong to a single component
whose name is that of the file it is stored in, minus its suffix. For example, suppose we write the following
program in a source file named “HelloWorld2.fss”:
export Executable
run(args) = print “Hi, it’s me again!”
When we compile this file:
fortress compile HelloWorld2.fss
the result is that a new component with the name HelloWorld2 is stored in the resident fortress. Once this
component is compiled, we can execute it by issuing the following command:
fortress run HelloWorld2
In a script file, there must be at most one component declaration. In a compiled file, multiple component declarations
may be included. For example, we could write the following file HelloWorld3.fss:
component HelloWorld
export Executable
run(args) = print “Hello, world!”
end
component HelloWorld2
export Executable
run(args) = print “Hi, it’s me again!”
end
When we compile this file, the result is that both the components HelloWorld and HelloWorld2 are stored in the
resident fortress.
If a fortress already contains a component with the same name as a newly installed component, the new component
shadows the old one. For example, if we first compile the source file HelloWorld3.fss above and then compile the
following file HelloWorld4.fss:
component HelloWorld
export Executable
run(args) = print “I didn’t expect that!”
end
then executing the component HelloWorld on our fortress will result in printing of the following text:
I didn’t expect that!
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