Choice rule groups

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Choice rule groups

A choice-rule-group consists of a number of rules that are tried in source order until the first redex is found. Rules are not evaluated until fixpoint; the manipulated graph is only searched until the first redex is found.

$\begin{verbsyntax}\synrule{Group}{'\{\vert' RangeDeclarations [ Declarations ] [ Options ] [ FIRSTCode ] } \lastcont{Rules [ LASTCode ] '\vert\}'} \end{verbsyntax}$

Because rule groups can be nested, choice-rule-groups offer a nice opportunity to specify alternative rule conditions:

$\begin{examplefoot}\{ // A normal rule group with nested sub-groups DECLARE r:D... ...EW newlabel:OneIdent;, EdgeTerminationLabels(r,newlabel) ; \} \end{examplefoot}$

Uwe Assmann
1998-12-22