Error Generators

Syntax

ErrorGenerator =
     "$error" Path.

Evaluation

The evaluation of a rest $error Q returns an error $error(Ge), where Ge is the result of evaluating the path Q.

     Env,0,St |- Q => Ge,St'
     --------------------------------------
     Env,m,St |- $error Q => $error(Ge),St'


     Env,0,St |- Q => $fail(0),St'
     -----------------------------------------------------------
     Env,m,St |- $error Q => $error(Fname "Unexpected fail"),St'
          Fname is the name of the function in  which
          the  construct appears.


     Env,0,St |- Q => $error(Ge),St'
     --------------------------------------
     Env,m,St |- $error Q => $error(Ge),St'