How to disable Perl 6 REPL creating .precomp - raku

Every time I run perl6 to enter the REPL mode, it creates a .precomp directory, which also slows down the appearance of the prompt. If the .precomp directory already exists, the prompt appears almost immediately, otherwise perl6 takes several seconds to create it.
Is there a way to disable this feature?

Check if you have a PERL6LIB environment variable set, and if it contains .. I can produce exactly the behavior you're encountering if I set that. The solution is to clear that from your PERL6LIB.

Related

Why can't Comma IDE find `raku` binary after a reboot?

I have a test that I'm running in Comma IDE from a Raku distro downloaded from github.
The tests passed last night. But after rebooting this morning, the test no longer passes. The test runs the raku on the machine. After some investigation, I discovered, that the binary was not getting found in the test:
say (run 'which', 'raku', :out).out.slurp; # outputs nothing
But if I run the test directly with prove6 from the command line, I get the full path to raku.
I'm using rakubrew.
I can easily fix this by adding the full path in the test, but I'm curious to know why Comma IDE sudddenly can't find the path to the raku binary.
UPDATE: I should also mention I reimported the proejct this morning and that caused some problems so I invalidated caches. So it may have been this and not the reboot that caused the problem. I'm unsure.
UPDATE 2: No surprise but
my $raku-path = (shell 'echo $PATH', :out).out.slurp;
yields only /usr/bin:/bin:/usr/sbin:/sbin
My best guess: in the situation where it worked, Comma was started from a shell where rakubrew had set up the environment. Then, after the reboot, Comma was started again, but from a shell where that was not the case.
Unless you choose to do otherwise, environment variables are passed on from parent process to child process. Comma inherits those from the process that starts it, and those are passed on to any Raku process that is spawned from Comma. Your options:
Make your Raku program more robust by using $*EXECUTABLE instead of which raku (this variable holds the path to the currently executing Raku implementation)
Make sure to start Comma from a shell where rakubrew has tweaked the path.
Tweak the environment variables in the Run Configuration in Comma.

Can I launch Dymola without the GUI?

I've got an application that I'm working on which currently takes a model, passes it to OpenModelica, compiles it, runs a simulation, and grabs the output. We'd like to switch over to use Dymola, but I can't figure out how to do this in a GUI-less fashion.
For instance, I've seen how I can use the javascript interface by running "dymola.exe -serverport 8082", but that actually still launches a GUI, and you can see everything running in the background when you use the javascript interface. Plus, closing the GUI kills the server.
Is there any way to use Dymola without a GUI? Note also that I can't simple use the .exe of a compile model, since compiling the model is one of the things I need to do.
Even easier is if there is a way for me to run my .mos file without the GUI launching.
you can use Dymola in command line mode and passing the right optional argument to not show its GUI.
You should use the following command :
C:/Program Files (x86)/Dymola 2016 FD01/bin64/Dymola.exe /nowindow myscript.mos
With the first part being the pass the the Dymola executable depending on where it was installed on your machine, the second one /nowindow being the optional argument stating that the GUI should not be displayed, and the third part path to your Modelica script which can contained the simulation setup.
Check the Dymola User Guide for additional details.
Best regards,
Gilles
From the command line, dymola.exe -nowindow.

Ipython QtConsole %edit

When using the magic function %edit from QtConsole with IPython, the call does not block, and does not execute the saved code. It does however save a temporary file...
I think this is intended behavior due to GUI editors and uncertainty, and whatever that reason is for not being able to communicate with subprocess (pyZMQ?).
What do you suggest as the best way to mix %edit/%run magics?
I would not mind calling two different commands (one to edit, and one after I have saved and execution is safe). But those commands need a way to synchronize this target file location, or someone to persist storage, and probably need some crude form of predicatably generating filenames such that you can edit more than one file at a time, and execute in arbitrarily. Session persistence is not a must.
Would writing my own magic do any good? Hope we can %edit macros soon, that would do well enough to make it work.
you shoudl be able to do %edit filename.py and %run filename.py. The non blocking behavior is expected, and IIRC due to technical reason. Not unsurmountable but difficult.
You could define your own magic if you wish, improvement are welcomed.
Hope we can %edit macros soon, that would do well enough to make it work.
For that too, PR are welcomed. I guess as a workaround/option you can %load macro which would put macro on input n+1 , edit it and redefine it, that might be a good extension for a cell magic %%macro macroname
If you have some executable code on your input (from QtConsole), you can type
%edit 1-5
This fires the editor, creates a temporarily file (automatically managed), and loads your input lines. This is nearly enough, now how to retrieve the name of that temp file pragmatically?
I see the print statement on Stdout, but its not visible to QtConsole AFAIK. Could maybe redirect stdout to catch that line, but that may not be an option anyway if your doing something else with stdout.
If I could retrieve the full pathname that was just created, this would be cake. Store it where some magics will know how to find it. Then issue a followup command when ready,pops the name off the stack, loads it into a macro, and run. All this with 2 input commands and no names to remember (unless you want to find and use that macro again, but for 1 shot stuff...)
How do I catch or retrieve the path of that temporary file?

Faster way of testing your prolog program

I am new to Prolog, and the task of launching the prolog interpreter from the terminal, typing consult('some_prolog_program.pl'), and then testing the predicate you just wrote is very time consuming, is there a way to run a scripted test to speed up development?
For example in C I can write a main where I would use the functions I defined, I can then execute:
make && ./a.out
to test the code, can I do something similar with Prolog?
You can have the interpreter always open and then recompile the file.
You can auto-run a predicate after compiling the file:
:- foo(4,2).
This will run foo(4,2) when the line is encountered in the file.
There are flags that can be used while launching (most) Prolog interpreters that allow you to compile a file and run predicates (check the man page). This way you could make a Bash script. The following will consult file.pl and run foo/0 using SWI-Prolog:
#!/bin/sh
exec swipl -q -f none -g "load_files([file],[silent(true)])" \
-t foo -- $*
This predicate will unify Arguments with a list of the flags you gave at the command line:
current_prolog_flag(argv, Arguments)
But unless you are going to run a lot of tests, I don't think that writing all this extra code will be faster.
Personally I really like the flexibility of testing any predicate at any time with or without tracing (see trace/0) without having to write extra code to call them (unlike in C).
P.S. about reloading the file without leaving the interpreter: You might have some problem if you have used dynamic predicates or global variables; you will have to do some cleaning.
You can invoke a test file from the command-line with prolog +l <file>
Also, you can build a single run_tests predicate that exercises a series of calls and validates the actual results against expected results. Here's an article with a good worked-out example: http://kenegozi.com/blog/2008/07/24/unit-testing-in-prolog
In SWI, you can load things as usual. Then, when you edit your files you simply say make. on the toplevel and it checks all dependencies automatically and only reloads the modified files.
For bigger projects it does make a lot of sense to use makefiles. In particular to do unit testing. See SWI's package plunit.
For simple scripts in SWI-Prolog, using REPL to test the code manually is usually good enough. Changed files can be reloaded via make/0 (?- make. on toplevel). Just keep the Prolog REPL running while editing, then save the edits, run make. in the REPL and hit ↑, ↑, Enter to execute the last query before the make. from history.
The main benefit of REPL is its interactivity:
You may fiddle with the arguments.
Transition to debugging or tracing (both command line and graphical) is easy.
You don't need to perform I/O to print the result. Output is handled by the toplevel, which prints the substitution. You see the whole substitution, not only its part you just happen to print (possibly accidentally overlooking other parts).
You may interactively choose how many substitutions you want to see for a goal that succeeds multiple times.
It is obvious if there is a choice point left after the last result returned by a non-deterministic predicate, which is hard to observe otherwise. In that case, false. is printed when backtracking beyond the last result.
If you need to preserve the test calls to repeat them later, create a protocol (transcript or "log" of the interactive session) and edit it to become a script, or even a test suite (see below). The protocol is a plain text file with escape sequences for the terminal, containing a verbatim copy of what you see during the interactive session. View the protocol using cat protocol.txt on Linux (and other *NIXes) or type protocol.txt on Windows.
If interactivity is not needed, perform the test calls from the command line non-interactively. Let's test the CLP(FD) factorial example n_factorial/2, saved in factorial.pl (don't forget to add :- use_module(library(clpfd)). when copying the code):
$ swipl -q -t "between(0, 9, N), n_factorial(N, F), format('~D ', F), fail." factorial.pl
1 1 2 6 24 120 720 5,040 40,320 362,880
On Windows, you may need to specify full path to swipl.exe as it's not in the PATH, probably.
If the call is always the same, you may save it to a shell script or Makefile (run would be a good name for the target).
In your current workflow for testing functions in C, you create a new program and call the function under test from its entry point (main function). Prolog scripts can have an entry point, too. See library(main). Prolog does not require compilation, so you can just directly call the script (./test.pl) without calling Make first.
For larger projects, you may want to create a less ad-hoc test suite. A unit testing framework like PlUnit is needed. Its use is beyond the scope of this answer; see the documentation.

How do you use CTEST_CUSTOM_PRE_TEST?

I've searched all the docs but can't seem to find a single example of using CTEST_CUSTOM_PRE_TEST.
Basically I need to start and run some commands on the server before the test runs. So I need to add a few pre-test steps. What's the syntax of CTEST_CUSTOM_PRE_TEST?
CTEST_CUSTOM_PRE_TEST( ??? what to put here ??? )
ADD_TEST(MyTest MyTestCommand)
CTEST_CUSTOM_PRE_TEST is a variable used in the context of running a ctest dashboard. It should either be set directly in the ctest -S script itself, or in a CTestCustom.cmake file at the top of your build tree.
In either file, an example value might be:
set(CTEST_CUSTOM_PRE_TEST "perl prepareForTesting.pl -with-this -and-that")
It should be a single command line, properly formatted for running on the system you're on. It runs once during a ctest_test call, before all the tests run. Similarly, there is also a CTEST_CUSTOM_POST_TEST variable, that should also be a single command line, but runs after all the tests are done.
Quoting and escaping args with spaces, quotes and backslashes may be challenging ... but maybe you won't need that, either.
I do not know of a real world example of this that I can point you to, but I can read the ctest source code... ;-)
Place set(CTEST_CUSTOM_PRE_TEST .. in a file which during cmake execution is copied to ${CMAKE_BINARY_DIR}/CTestCustom.cmake. For details, see https://stackoverflow.com/a/37748933/1017348.
In OpenSCAD on headless linux we attempt to startup a virtual framebuffer before ctest runs. We don't use PRE_TEST though. We build our own CTestCustom.cmake in the build directory during the 'cmake' run. (We do use POST_TEST, but there were a few recent versions of cmake where POST_TEST was broken)
You can find the code here https://github.com/openscad/openscad/blob/master/tests