Modules as blobs

Author(s): Isabel Garcia-Contreras, Jose F. Morales.

This module implements (temporary) modules-as-blobs facilities. They allow the runtime creation of modules from strings and terms.

Implementation

Run-time creation of modules is currently implemented by writing the module code into a unique temporary directory (using the system mktemp_in_tmp/2 predicate).

Currently they need to be deleted explicitly.

Note that this is a temporary solution before read/write stream operations can be work on in-memory objects.

Examples

The predicate new_modblob/4 creates a new temporary module, that can be deleted with delete_modblob/1.

Module creation requires the module name, export list, program clauses, and returns the module object (currently a path). If a module directive is specified, the export list is ignored.

Example:

?- new_modblob([(p(A) :- q(A)), (q(b))], [p/1], my_tmp_mod, ModBlob), modblob_path(ModBlob, Path).
Path = '/tmp/tmp_modsfbMY9Y/my_tmp_mod.pl' ?

where the contents of /tmp/tmp_modsfbMY9Y/my_tmp_mod.pl are:

:-module(_,[p/1],[]).
p(A) :-
    q(A).
q(b).

Usage and interface

Library usage:
:- use_module(library(modblobs)).
Exports:
- Predicates:
  new_modblob/4, delete_modblob/1, modblob_path/2.

Documentation on exports

PREDICATEnew_modblob/4

Usage:new_modblob(Clauses,ExportedPreds,ModName,ModBlob)

Write clauses Clauses in a temporary module identified by ModBlob.

The following properties should hold at call time:
(basic_props:list/1)Clauses is a list.
(basic_props:list/1)ExportedPreds is a list.
(basic_props:atm/1)ModName is an atom.
(term_typing:var/1)ModBlob is a free variable.
The following properties should hold upon exit:
(basic_props:list/1)Clauses is a list.
(basic_props:list/1)ExportedPreds is a list.
(basic_props:atm/1)ModName is an atom.
(modblobs:modblob/1)ModBlob is a is a temporary module object

PREDICATEdelete_modblob/1

Usage:delete_modblob(ModBlob)

Removes the data associated to ModBlob

The following properties should hold at call time:
(modblobs:modblob/1)ModBlob is a is a temporary module object
The following properties should hold globally:
(native_props:is_det/1)All calls of the form delete_modblob(ModBlob) are deterministic.

PREDICATEmodblob_path/2

Usage:modblob_path(ModBlob,ModPath)

Obtain the temporary file associated to ModBlob

The following properties should hold at call time:
(basic_props:atm/1)ModBlob is an atom.
The following properties should hold upon exit:
(basic_props:atm/1)ModPath is an atom.

Documentation on imports

This module has the following direct dependencies:

System library modules:
native_props, datafacts_rt, system, system_extra, write, pathnames.
Packages:
prelude, initial, condcomp, assertions, assertions/assertions_basic, modes, regtypes, nativeprops, datafacts.