The Fortress Language Specification - CiteSeerX

The ways in which fortresses are actually realized on particular platforms are beyond the scope of this specification.
An implementor might choose to instantiate a fortress as a process, or as a persistent object database stored in a file
system, with fortress operations being implemented as scripts that manipulate this database.
We call the source code for a single software component a project. Typically, when a project written in other programming
languages is compiled, each file in the project is separately compiled. To ship an application, these files are
linked together to form an application or library. Fortress uses a different model: a project is compiled directly into a
single component, which is installed in the compiling fortress.
From the point of view of the compiler, all the source code for a project is contained in a single file. This approach simplifies
the design, and gives a well-defined order for initialization of static elements of the component. However, this
approach is unworkable for components of substantial size. Therefore, the compiler can be instructed to concatenate
several source files together before compiling, while maintaining the original source location information.
After these components are compiled from source files, they can then be linked together to form larger components.
22.2 Components
Syntax:
Component ::= component DottedId Import ∗ Export ∗ Decl ∗ end
DottedId ::= Id ( . Id) ∗
Import ::= import ImportFrom from DottedId
| import AliasedDottedIds
ImportFrom ::= * [except Names]
| AliasedNames
Names ::= Name
| { NameList }
Name ::= Id
| opr Op
NameList ::= Name ( , Name) ∗
AliasedNames ::= AliasedName
| { AliasedNameList }
AliasedName ::= Id [as DottedId]
| opr Op [as Op]
| opr LeftEncloser RightEncloser [as LeftEncloser RightEncloser]
AliasedNameList ::= AliasedName ( , AliasedName) ∗
AliasedDottedIds ::= AliasedDottedId
| { AliasedDottedIdList }
AliasedDottedId ::= DottedId [as DottedId]
AliasedDottedIdList ::= AliasedDottedId ( , AliasedDottedId) ∗
Export ::= export DottedIds
DottedIds ::= DottedId
| { DottedIdList }
DottedIdList ::= DottedId ( , DottedId) ∗
In this specification, we will refer to components created by compiling a file as simple components, while components
created by linking components together will be known as compound components.
The source code of a simple component definition begins with the special reserved word component followed by
a possibly qualified name (an identifier or a sequence of identifiers separated by periods with no intervening whitespace),
followed by a sequence of import statements, and a sequence of export statements, and finally a sequence of
declarations.
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