sicstus.pl -- SICStus 3 compatibility library

This library is intended to be activated using the directive below in files that are designed for use with SICStus Prolog 3. The changes are in effect until the end of the file and in each file loaded from this file.

:- expects_dialect(sicstus).

This library only provides compatibility with version 3 of SICStus Prolog. For SICStus Prolog 4 compatibility, use library(dialect/sicstus4) instead.

To be done: - The dialect-compatibility packages are developed in a `demand-driven' fashion. Please contribute to this package.

push_sicstus_library[private]

Pushes searching for dialect/sicstus in front of every library directory that contains such as sub-directory.

setup_dialect[private]

Further dialect initialization.

Currently this disables quoting when printing atoms, which SWI does by default, but SICStus doesn't. This globally modifies the print_write_options Prolog flag, so this change also affects code that doesn't request SICStus compatibility.

if(:If, :Then, :Else)

Same as SWI-Prolog soft-cut construct. Normally, this is translated using goal-expansion. If either term contains a !, we use meta-calling for full compatibility (i.e., scoping the cut).

rename_module(?SICStusModule, ?RenamedSICSTusModule) is nondet[multifile]

True if RenamedSICSTusModule is the name that we use for the SICStus native module SICStusModule. We do this in places where the module-name conflicts. All explicitely qualified goals are mapped to the SICStus equivalent of the module.

use_module(+Module, -File, +Imports) is det

use_module(-Module, +File, +Imports) is det

This predicate can be used to import from a named module while the file-location of the module is unknown or to get access to the module-name loaded from a file.

If both Module and File are given, we use Module and try to unify File with the absolute canonical path to the file from which Module was loaded. However, we succeed regardless of the success of this unification.

bb_put(:Name, +Value) is det

bb_get(:Name, -Value) is semidet

bb_delete(:Name, -Value) is semidet

bb_update(:Name, -Old, +New) is semidet

SICStus compatible blackboard routines. The implementations only deal with cases where the module-sensitive key is unknown and meta-calling. Simple cases are directly mapped to SWI-Prolog non-backtrackable global variables.

is_mutable(@Term) is det

True if Term is bound to a mutable term.

Compatibility: - sicstus

create_mutable(?Value, -Mutable) is det

Create a mutable term with the given initial Value.

Compatibility: - sicstus

get_mutable(?Value, +Mutable) is semidet

True if Value unifies with the current value of Mutable.

Compatibility: - sicstus

update_mutable(?Value, !Mutable) is det

Set the value of Mutable to Value. The old binding is restored on backtracking.

See also: - setarg/3.
Compatibility: - sicstus

read_line(-Codes) is det

read_line(+Stream, -Codes) is det

Read a line from the given or current input. The line read does not include the line-termination character. Unifies Codes with end_of_file if the end of the input is reached.

See also: - The SWI-Prolog primitive is read_line_to_codes/2.
Compatibility: - sicstus

trimcore is det

Trims the stacks and releases unused heap memory to the operating system where possible. Other tasks of the SICStus trimcore/0 are automatically scheduled by SWI-Prolog.

prolog_flag(+Flag, -Old, +New) is semidet

Query and set a Prolog flag. Use the debug/1 topic prolog_flag to find the flags accessed using this predicate.

prolog:$breaklevel(-BreakLevel, Unknown)[private]

Query the current break-level

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.

bb_put(:Name, +Value) is det

bb_get(:Name, -Value) is semidet

bb_delete(:Name, -Value) is semidet

bb_update(:Name, -Old, +New) is semidet

bb_put(:Name, +Value) is det

bb_get(:Name, -Value) is semidet

bb_delete(:Name, -Value) is semidet

bb_update(:Name, -Old, +New) is semidet

bb_put(:Name, +Value) is det

bb_get(:Name, -Value) is semidet

bb_delete(:Name, -Value) is semidet

bb_update(:Name, -Old, +New) is semidet

read_line(-Codes) is det

read_line(+Stream, -Codes) is det

Read a line from the given or current input. The line read does not include the line-termination character. Unifies Codes with end_of_file if the end of the input is reached.

See also: - The SWI-Prolog primitive is read_line_to_codes/2.
Compatibility: - sicstus

block +Heads

Declare predicates to suspend on certain modes. The argument is, like meta_predicate/1, a comma-separated list of modes (BlockSpecs). Calls to the predicate is suspended if at least one of the conditions implies by a blockspec evaluated to true. A blockspec evaluated to true iff all arguments specified as `-' are unbound.

Multiple BlockSpecs for a single predicate can appear in one or more :- block declarations. The predicate is suspended untill all mode patterns that apply to it are satisfied.

The implementation is realised by creating a wrapper that checks the block conditions and either calls the original predicate immediately (if none of the block conditions were true) or uses attributed variables to delay re-evaluating the block condition until any of the arguments in question are bound.

Compatibility: - SICStus Prolog

Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

sicstus_is_readable_stream(Arg1)
statistics(Arg1, Arg2)