FOSD metamodels

A metamodel is a model whose instances are models.{{cite web | title=Scaling Step-Wise Refinement | archive-url=https://web.archive.org/web/20170706122700/ftp://ftp.cs.utexas.edu/pub/predator/TSE-AHEAD.pdf | archive-date=2017-07-06 | url-status=dead | url=ftp://ftp.cs.utexas.edu/pub/predator/TSE-AHEAD.pdf}} A GenVoca model of a product line is a tuple whose components are features (0-ary or 1-ary functions). An extension (a.k.a. delta or refinement) of a model is a "meta-feature", which is a tuple of deltas that can modify an existing product line by modifying existing features and adding new features. As a simple example, consider GenVoca model M that contains three features a-c:

:$M\; =\; [\; a,\; b,\; c\; ]$

Suppose meta-model MM contains three meta-features AAA-CCC, each of which

is a tuple with a single non-identity feature:

:$$

\begin{align}

MM & = [ AAA, BBB, CCC ] \\

& = [ [a,0,0], [0,b,0], [0,0,c] ]

\end{align}

where 0 is the null feature. Model M is constructed by adding the meta-features of MM, where + is the composition operation (see FOSD).

:$$

\begin{align}

M & = AAA + BBB + CCC & \text{expression} \\

& = [a,0,0]+[0,b,0]+[0,0,c] & \text{substitution} \\

& = [a+0+0, 0+b+0, 0+0+c] & \text{composition} \\

& = [a,b,c] & \text{simplification where } 0+x=x+0=x

\end{align}

MM models a product line of product lines (PL**2). That is, different MM expressions correspond to GenVoca models of different product lines..

• Feature-oriented programming – basic overview
• FOSD origami
• FOSD program cubes – multi-dimensional product lines
• FOSD feature interactions – other operations on features, including an operation designating feature interaction

Category:Feature-oriented programming