ExtUtils::XSSymSet(3perl)        Perl Programmers Reference Guide       ExtUtils::XSSymSet(3perl)



NAME
       ExtUtils::XSSymSet - keep sets of symbol names palatable to the VMS linker

SYNOPSIS
         use ExtUtils::XSSymSet;

         $set = new ExtUtils::XSSymSet;
         while ($sym = make_symbol()) { $set->addsym($sym); }
         foreach $safesym ($set->all_trimmed) {
           print "Processing $safesym (derived from ",
               $self->get_orig($safesym), ")\n";
           do_stuff($safesym);
         }

         $safesym = ExtUtils::XSSymSet->trimsym($onesym);

DESCRIPTION
       Since the VMS linker distinguishes symbols based only on the first 31 characters of their
       names, it is occasionally necessary to shorten symbol names in order to avoid collisions.
       (This is especially true of names generated by xsubpp, since prefixes generated by nested
       package names can become quite long.)  "ExtUtils::XSSymSet" provides functions to shorten
       names in a consistent fashion, and to track a set of names to insure that each is unique.
       While designed with xsubpp in mind, it may be used with any set of strings.

       This package supplies the following functions, all of which should be called as methods.

       new([$maxlen[,$silent]])
           Creates an empty "ExtUtils::XSSymset" set of symbols.  This function may be called as
           a static method or via an existing object.  If $maxlen or $silent are specified, they
           are used as the defaults for maximum name length and warning behavior in future calls
           to addsym() or trimsym() via this object.  If the compiler has been instructed to do
           its own symbol shortening via $Config{'useshortenedsymbols'}, a value of 2048 is
           assumed for $maxlen as a way of bypassing the shortening done by this module.

       addsym($name[,$maxlen[,$silent]])
           Creates a symbol name from $name, using the methods described under trimsym(), which
           is unique in this set of symbols, and returns the new name.  $name and its resultant
           are added to the set, and any future calls to addsym() specifying the same $name will
           return the same result, regardless of the value of $maxlen specified.  Unless $silent
           is true, warnings are output if $name had to be trimmed or changed in order to avoid
           collision with an existing symbol name.  $maxlen and $silent default to the values
           specified when this set of symbols was created.  This method must be called via an
           existing object.

       trimsym($name[,$maxlen[,$silent]])
           Creates a symbol name $maxlen or fewer characters long from $name and returns it. If
           $name is too long, it first tries to shorten it by removing duplicate characters, then
           by periodically removing non-underscore characters, and finally, if necessary, by
           periodically removing characters of any type.  $maxlen defaults to 31.  Unless $silent
           is true, a warning is output if $name is altered in any way.  This function may be
           called either as a static method or via an existing object, but in the latter case no
           check is made to insure that the resulting name is unique in the set of symbols.    If
           the compiler has been instructed to do its own symbol shortening via
           $Config{'useshortenedsymbols'}, a value of 2048 is assumed for $maxlen as a way of
           bypassing the shortening done by this module.

       delsym($name)
           Removes $name from the set of symbols, where $name is the original symbol name passed
           previously to addsym().  If $name existed in the set of symbols, returns its "trimmed"
           equivalent, otherwise returns "undef".  This method must be called via an existing
           object.

       get_orig($trimmed)
           Returns the original name which was trimmed to $trimmed by a previous call to
           addsym(), or "undef" if $trimmed does not correspond to a member of this set of
           symbols.  This method must be called via an existing object.

       get_trimmed($name)
           Returns the trimmed name which was generated from $name by a previous call to
           addsym(), or "undef" if $name is not a member of this set of symbols.  This method
           must be called via an existing object.

       all_orig()
           Returns a list containing all of the original symbol names from this set.

       all_trimmed()
           Returns a list containing all of the trimmed symbol names from this set.

AUTHOR
       Charles Bailey  <bailey AT newman.edu>

REVISION
       Last revised 8-Oct-2010, for Perl 5.13.6.



perl v5.20.2                                2014-12-27                  ExtUtils::XSSymSet(3perl)