10.1.3.3 User Defined Location Type

Instead of using the built-in types you may use the %define variable api.location.type to specify your own type:

%define api.location.type {LocationType}

The requirements over your LocationType are:

• it must be copyable;
• in order to compute the (default) value of @$ in a reduction, the parser basically runs

  @$.begin = @$1.begin;
  @$.end   = @$N.end; // The location of last right-hand side symbol.
  

  so there must be copyable begin and end members;

• alternatively you may redefine the computation of the default location, in which case these members are not required (see section Default Action for Locations);
• if traces are enabled, then there must exist an ‘std::ostream& operator<< (std::ostream& o, const LocationType& s)’ function.

In programs with several C++ parsers, you may also use the %define variable api.location.type to share a common set of built-in definitions for position and location. For instance, one parser ‘master/parser.yy’ might use:

%defines
%locations
%define api.namespace {master::}

to generate the ‘master/position.hh’ and ‘master/location.hh’ files, reused by other parsers as follows:

%define api.location.type {master::location}
%code requires { #include <master/location.hh> }

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