Upgrade

Upgrading is a special variation of replacement and a slightly more powerful and liberal form of folding. This operator replaces an expression by a nonterminal that can be evaluated to it. The first parameter is the scope production with an expression marked. The second parameter is one of that nonterminal’s definitions, which right hand side equals that expression.

Syntax

upgrade:
        marked-production production

Example

Given the input:

a:
        d e c
b:
        d e
b:
        f g

After using this transformation:

upgrade(
 a:
        <b> c
 b:
        d e
);

The result will look like this:

a:
        b c
b:
        d e
b:
        f g

Relevant files

• shared/prolog/xbgf1.pro
• shared/rascal/src/transform/library/Folding.rsc
• shared/xsd/xbgf.xsd

See also

• Upgrade is a part of XBGF

Contributors

• Ralf Lämmel (@rlaemmel)
• Vadim Zaytsev (@grammarware)