NAME
src/pmc/exporter.pmc - Exporter PMC
SYNOPSIS
Export globals from one namespace to another.
You can use Exporter in PIR to import subs from a library. At its simplest:
.sub main :main load_bytecode 'Test/More.pir' .local pmc exporter, src_ns, dest_ns src_ns = get_namespace [ 'Test'; 'More' ] exporter = new 'Exporter' exporter.'import'( src_ns :named('source') 'plan ok' :named('globals') ) plan(1) ok(1, 'exporter has imported the requested functions') .end
You can also specify the exporter attributes before making the import call, for example to import into the alternate namespace 'Foo' you could use the following code:
src_ns = get_namespace [ 'Test'; 'More' ] dest_ns = get_namespace [ 'Foo' ] exporter.'source'(src_ns) exporter.'destination'(dest_ns) exporter.'import'('plan ok' :named('globals'))
You can even import subroutines under different names if globals is a hash:
globals = new 'Hash' globals['plan'] = 'steps' globals['ok'] = 'passed' exporter.'import'(globals :named('globals')) steps(1) passed(1)
DESCRIPTION
Exports globals from one namespace to another. Exporter always uses the typed namespace interface, as outlined in docs/pdds/pdd21_namespaces.pod.
Exporter is not derived from any other PMC, and does not provide any vtable interface--its interface consists solely of methods, not vtable functions.
Structure
The Exporter PMC structure (Parrot_Exporter
) consists of three items:
ns_src
The source namespace -- a NameSpace PMC. A Null PMC is allocated during initialization.
ns_dest
The destination namespace -- a NameSpace PMC. A PMC representing the current namespace is allocated upon initialization.
globals
The globals to export -- a PMC that implements a hash, an array, a String containing a list of space-separated subroutine names or Null.A Null PMC is allocated during initialization.
Functions
void init()
Initializes an Exporter PMC.
void mark()
Mark referenced strings and PMCs in the structure as live.
Methods
METHOD source(PMC *src :optional, int got_src :opt_flag)
Accessor for the source NameSpace object (METHOD destination(PMC *dest :optional, int got_dest :opt_flag)
Accessor for the destination NameSpace object (METHOD globals(PMC *glb :optional, int got_glb :opt_flag)
Accessor for the globals to export (METHOD import(PMC *dest :optional :named("destination"), int got_dest :opt_flag, PMC *src :optional :named("source"), int got_src :opt_flag, PMC *globals :optional :named("globals"), int got_globals :opt_flag)
Import
ns_src
.) Sets the value if src
is passed, otherwise returns the value. Throws an exception if a non-NameSpace PMC is passed.
ns_dest
.) Sets the value if dest
is passed, otherwise returns the value. Throws an exception if a non-NameSpace PMC is passed.
globals
.) Sets the value if glb
is passed, otherwise returns the value. If glb
is a String, it is split on ascii whitespace, and each array member is added as a hash key. If glb
implements the array interface, each member is added as a hash key. if glb
implements the hash interface, it is assigned to Exporter's globals
attribute. Throws an exception if an unknown PMC type is passed.
globals
from the src
namespace to the dest
namespace. If src
, dest
, or globals
are passed, they override the current value. import
follows the semantics of the export_to
method of the NameSpace
PMC. in particular, if a NULL value is passed for globals
, the default set of items will be imported. Throws an exception upon error.STABILITY
Unstable. This PMC is under active development; major portions of the interface have not yet been completed.
SEE ALSO
docs/pdds/pdd17_basic_types.pod, docs/pdds/pdd21_namespaces.pod.