Buckminster Dependency Specification
Buckminster creates component dependency graphs using a Dependency Specification, henceforth referred to as "dspec". A dspec is either obtained using a dspec builder or exists as a physical file in the component that it defines. Buckminster delivers dspec builders for Eclipse update-site's, features, plug-ins, and fragments. New builders can be added as needed (see Component type).
A dspec defines the top-level element dependencies as a list of dependency elements.
A dependency graph is always implicit since dependencies appoint other components and all components can be viewed in terms of a dspec. This implicit graph must be a Directed Acyclic Graph (DAG).
One of the fundamental concepts of Buckminster is that a component does not really have any dependencies unless you do something with it. The dependency graph might be very different for different needs. This very important extension to the overall concept is covered by the Action Specification. A free standing Dependency Specification can be seen as an Action Specification with one single action that requires all dependencies and imposes default behavior for the resolution.
A version designator appoints the specific component versions that will
satisfy a component request. It uses the semantics similar the OSGi Version
Range and appoints versions using a mathematical interval notation. See Mathematical
Convention for Interval Notation.
The notation "2.3.4" is equivalent to the mathematical range
"[2.3.4,∞)". The version
designator differs from the OSGi range in that the version in itself is
interpreted by a version type. OSGi uses a fixed
The type knows how to parse and compare versions. Buckminster comes with the following predefined version types:
- Assumes that the version has the following grammar:
version ::= major( '.' minor ( '.' micro ( '.' qualifier )? )? )? major ::= number // See 1.4.2 minor ::= number micro ::= number qualifier ::= ( alphanum | ’_’ | '-' )+
- Will allow any string that does not contain the characters that delimit ranges.
New version types can be added using the extension-point org.eclipse.buckminster.core.versionTypes.