ExtUtils::XSSymSet(3pm)Perl Programmers Reference GuideExtUtils::XSSymSet(3pm)
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@newman.upenn.edu>
REVISION
Last revised 8-Oct-2010, for Perl 5.13.6.
perl v5.24.0 2016-02-05 ExtUtils::XSSymSet(3pm)
perl 5.24 - Generated Sun Nov 13 07:07:47 CST 2016