quintus.pl -- Quintus compatibility

This module defines several predicates from the Quintus Prolog libraries. Note that our library structure is totally different. If this library were complete, Prolog code could be ported by removing the use_module/1 declarations, relying on the SWI-Prolog autoloader.

Bluffers guide to porting:

Remove use_module(library(...))
Run ?- list_undefined.
Fix problems

Of course, this library is incomplete ...

unix(+Action)

This predicate provides a partial emulation of the corresponding Quintus predicate. It provides access to some operating system features and unlike the name suggests, is not operating system specific. Defined actions are below.

system(+Command): Equivalent to shell(Command)
shell(+Command): Equivalent to shell(Command)
access(File,0): Equivalent to access_file(File, read)
cd(Dir): Equivalent to working_directory(_, Dir)
args(List): Equivalent to current_prolog_flag(os_argv, List).
argv(List): Equivalent to args(List), but arguments that are syntactically valid numbers are passed as a number.

otherwise

For (A -> B ; otherwise -> C)

abs(+Number, -Absolute)

Unify `Absolute' with the absolute value of `Number'.

sin(+Angle, -Sine) is det

cos(+Angle, -Cosine) is det

tan(+Angle, -Tangent) is det

log(+X, -NatLog) is det

log10(+X, -Log) is det

pow(+X, +Y, -Pow) is det

ceiling(+X, -Value) is det

floor(+X, -Value) is det

round(+X, -Value) is det

sqrt(+X, -Value) is det

acos(+X, -Value) is det

asin(+X, -Value) is det

atan(+X, -Value) is det

atan2(+Y, +X, -Value) is det

sign(+X, -Value) is det

Math library predicates. SWI-Prolog (and ISO) support these as functions under is/2, etc.

deprecated: - Do not use these predicates except for compatibility reasons.
Compatibility: - Quintus Prolog.

genarg(?Index, +Term, ?Arg) is nondet

Generalised version of ISO arg/3. SWI-Prolog's arg/3 is already genarg/3.

prolog_flag(?Flag, ?Value) is nondet

Same as ISO current_prolog_flag/2. Maps version.

bug: - Should map relevant Quintus flag identifiers.

date(-Date) is det

Get current date as date(Y,M,D)

no_style_check(Style) is det

Same as SWI-Prolog style_check(-Style). The Quintus option single_var is mapped to singleton.

See also: - style_check/1.

mode(+ModeDecl) is det

Ignore a DEC10/Quintus :- mode(Head) declaration. Typically these declarations are written in operator form. The operator declaration is not part of the Quintus emulation library. The following declaration is compatible with Quintus:

:- op(1150, fx, [(mode)]).

simple(@Term) is semidet

Term is atomic or a variable.

current_stream(?Object, ?Mode, ?Stream)

SICStus/Quintus and backward compatible predicate. New code should be using the ISO compatible stream_property/2.

stream_position(+Stream, -Old, +New)

True when Old is the current position in Stream and the stream has been repositioned to New.

deprecated: - New code should use the ISO predicates stream_property/2 and set_stream_position/2.

skip_line is det

skip_line(Stream) is det

Skip the rest of the current line (on Stream). Same as skip(0'\n).

compile(+Files) is det

Compile files. SWI-Prolog doesn't distinguish between compilation and consult.

See also: - load_files/2.

atom_char(+Char, -Code) is det

atom_char(-Char, +Code) is det

Same as ISO char_code/2.

midstring(?ABC, ?B, ?AC) is nondet

midstring(?ABC, ?B, ?AC, LenA) is nondet

midstring(?ABC, ?B, ?AC, LenA, LenB) is nondet

midstring(?ABC, ?B, ?AC, LenA, LenB, LenC) is nondet

Too difficult to explain. See the Quintus docs. As far as I understand them the code below emulates this function just fine.

raise_exception(+Term)

Quintus compatible exception handling

on_exception(+Template, :Goal, :Recover)

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.