This module provides partial compatibility with the XSB Prolog system

 setup_dialect

Further dialect initialization. Called from expects_dialect/1.

 xsb_import(:Predicates, +From)

Make Predicates visible in From. As the XSB library structructure is rather different from SWI-Prolog's, this is a heuristic process.

 xsb_set_prolog_flag(+Flag, +Value)

Map some XSB Prolog flags to their SWI-Prolog's equivalents.

 compile(File, Options)

The XSB version compiles a file into .xwam without loading it. We do not have that. Calling qcompile/1 seems the best start.

 load_dyn(+FileName) is det

 load_dyn(+FileName, +Direction) is det

 load_dync(+FileName) is det

 load_dync(+FileName, +Direction) is det

Proper implementation requires the Quintus all_dynamic option. SWI-Prolog never had that as clause/2 is allowed on static code, which is the main reason to want this.

The dync versions demand source in canonical format. In SWI-Prolog there is little reason to demand this.

 set_global_compiler_options(+List) is det

Set the XSB global compiler options.

 compiler_options(+Options) is det

Locally switch the compiler options

 fail_if(:P)

Same as \+ (support XSB legacy code). As the XSB manual claims this is optimized we normally do goal expansion to \+/1.

 sk_not(:P) is semidet

Sound negation with non-ground P. Equivalent to not_exists/1.

deprecated

- New code should use not_exists/1.

 gc_tables(-Remaining) is det

The table abolish predicates leave the actual destruction of the tables to the atom garbage collector to avoid deleting active tables. This predicate runs garbage_collect_atoms/0 and counts the remaining erased tables.

Compatibility

- Due to the heuristic nature of garbage_collect_atoms/0, not all tables may be reclaimed immediately.

 cputime(-Seconds) is det

True when Seconds is the used CPU time.

 walltime(-Seconds) is det

True when Seconds is the wall time sice Prolog was started

 debug_ctl(+Option, +Value) is det

Control the XSB debugger. The current implementation merely defines the predicate. Much more can be mapped to SWI-Prolog primitives.

 thread_shared(+Spec)

Declare a dynamic predicate as shared. This is the default for SWI-Prolog.

 fmt_write(+Fmt, +Term) is det

 fmt_write(+Stream, +Fmt, +Term) is det

C-style formatted write, where the arguments are formed by the arguments of Term. We map this to format/2,3.

bug

- We need to complete the translation of the fmt_write sequences to format/2,3 sequences.

 path_sysop(+Op, ?Value) is semidet

 path_sysop(+Op, ?Arg1, ?Arg2) is semidet

Unified interface to the operations on files. All these calls succeed iff the corresponding system call succeeds.

Compatibility

- The below implementation covers all operations from XSB 3.8. SWI file name operations are always on POSIX style file names. The implementation may have semantic differences.

 abort(+Message:atomic)

Abort with a message

Re-exported predicates

The following predicates are exported from this file while their implementation is defined in imported modules or non-module files loaded by this module.

 load_dyn(+FileName) is det

 load_dyn(+FileName, +Direction) is det

 load_dync(+FileName) is det

 load_dync(+FileName, +Direction) is det

Proper implementation requires the Quintus all_dynamic option. SWI-Prolog never had that as clause/2 is allowed on static code, which is the main reason to want this.

The dync versions demand source in canonical format. In SWI-Prolog there is little reason to demand this.

 load_dyn(+FileName) is det

 load_dyn(+FileName, +Direction) is det

 load_dync(+FileName) is det

 load_dync(+FileName, +Direction) is det

Proper implementation requires the Quintus all_dynamic option. SWI-Prolog never had that as clause/2 is allowed on static code, which is the main reason to want this.

The dync versions demand source in canonical format. In SWI-Prolog there is little reason to demand this.

 load_dyn(+FileName) is det

 load_dyn(+FileName, +Direction) is det

 load_dync(+FileName) is det

 load_dync(+FileName, +Direction) is det

Proper implementation requires the Quintus all_dynamic option. SWI-Prolog never had that as clause/2 is allowed on static code, which is the main reason to want this.

The dync versions demand source in canonical format. In SWI-Prolog there is little reason to demand this.

 fmt_write(+Fmt, +Term) is det

 fmt_write(+Stream, +Fmt, +Term) is det

C-style formatted write, where the arguments are formed by the arguments of Term. We map this to format/2,3.

bug

- We need to complete the translation of the fmt_write sequences to format/2,3 sequences.

 path_sysop(+Op, ?Value) is semidet

 path_sysop(+Op, ?Arg1, ?Arg2) is semidet

Unified interface to the operations on files. All these calls succeed iff the corresponding system call succeeds.

Compatibility

- The below implementation covers all operations from XSB 3.8. SWI file name operations are always on POSIX style file names. The implementation may have semantic differences.

 add_lib_dir(+Directories) is det

 add_lib_dir(+Root, +Directories) is det

Add members of the comma list Directories to library_directory/1. If Root is given, all members of Directories are interpreted relative to Root.

 add_lib_dir(+Directories) is det

 add_lib_dir(+Root, +Directories) is det

Add members of the comma list Directories to library_directory/1. If Root is given, all members of Directories are interpreted relative to Root.

 timed_call(:Goal, :Options)

Emulation for XSB timed_call/2. Runs Goal as once/1 with timed interrupts. The interrupt goals are called as interrupts using the semantics of ignore/1: possible choice points are cut and failure is ignored. If the interrupt throws an exception this is propagated.

Options is a list of the terms below. At least one of the terms max/2 or repeating/2 must be present.

max(+MaxInterval, :MaxHandler)

Schedule a single interrupt calling MaxHandler at MaxInterval milliseconds from now.

repeating(+RepInterval, :RepHandler)

Schedule a repeating interrupt calling RepHandler each RepInterval milliseconds.

nesting

Nested calls to timed_call/2 are transformed into calls to once/1. Without nesting, a nested call raises a permission_error exception.

See also

- call_with_time_limit/2, alarm/4, thread_signal/2.

Compatibility

- This predicate is a generalization of the SWI-Prolog library(time) interface. It is left in the XSB emulation because it uses non-standard option syntax and the time is in milliseconds where all SWI-Prolog time handling uses seconds.