with_thread_local

Call a Goal with local assertions

Installation using SWI-Prolog 7.1 or later:

`?- pack_install('https://github.com/TeamSPoon/with_thread_local.git'). `

Source code available and pull requests accepted at http://github.com/logicmoo/with_thread_local

locally_each( :Effect, :Call) is nondet.

Temporally have :Effect (see locally/2)

But Ensure Non-determism is respected (effect is undone between each Redo)

uses each_call_cleanup/3 instead of setup_call_cleanup/3 (slightly slower?)

for example,

locally_each/2 works (Does not throw)

  ?- current_prolog_flag(xref,Was), 
      locally_each(set_prolog_flag(xref,true),
      assertion(current_prolog_flag(xref,true));assertion(current_prolog_flag(xref,true))),
      assertion(current_prolog_flag(xref,Was)),fail.

locally/2 is little less carefull so it should not work (it throws instead)

?- current_prolog_flag(xref,Was), 
    locally(set_prolog_flag(xref,true),
    assertion(current_prolog_flag(xref,true));assertion(current_prolog_flag(xref,true))),
    assertion(current_prolog_flag(xref,Was)),fail.

locally( :Effect, :Call) is nondet.

Effect may be of type:

set_prolog_flag - Temporarily change prolog flag

op/3 - change op

$gvar=Value - set a global variable

Temporally (thread_local) Assert some :Effect

use locally_each/3 if respecting Non-determism is important (slightly slower?)

  ?- current_prolog_flag(xref,Was), 
      locally(set_prolog_flag(xref,true),
      assertion(current_prolog_flag(xref,true))),
      assertion(current_prolog_flag(xref,Was)). 

Some TODOs

Document this pack!

Write tests

Untangle the 'pack' install deps (Moving predicates over here from logicmoo_base)

Not obligated to maintain a git fork just to contribute

Dislike having tons of forks that are several commits behind the main git repo?

Be old school - Please ask to be added to TeamSPoon and Contribute directly !

Still, we wont stop you from doing it the Fork+PullRequest method

BSD 2-Clause License

Copyright (c) 2017, TeamSPoon and Douglas Miles logicmoo@gmail.com All rights reserved.