DataClass

Concept: Partial

Abstract

Capable of being defined in several different source files which are merged at compile time and treated as though they were all one source file.

Body

A class of databases being partial does not simply mean that all of your .dbc files are concatenated prior to compilation. Instead it means that each one is parsed, then the parse trees are logically merged together into a single tree. That tree is what gets compiled so, to the compiler, it is as though you put everything in one .dbc file.

Take for instance, the following two files. If they were simple concatenated, then DataClass would think you wanted two databases with the exact same name.

database X { version 1.0 : initialized { } }

X-1.0.cs

database X { version 2.0 : 1.0 { } }

X-2.0.cs

However, because database classes are partial, this is what the compiler sees after parsing:

database X {
  version 1.0 : initialized { }
  version 2.0 : 1.0 { }
}

Note that not all structures are partial. In DataClass, only database classes are. Versions and their constituents are non-partial. So the following code would fail to compile:

database X {
  version 1.0 : initialized { }
  version 1.0 : initialized { }
}

Related Use Cases

• Organizing database versions

Related Concepts

• Class of databases
• Version

Related Keywords

• database
• open curly
• version
• version number
• :
• initialized
• close curly

Other Actions

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