How to generate all the leaf to leaf path in an AST? - abstract-syntax-tree

Given a JS snippet, how to generate all the leaf-to-leaf path from the AST?
Let’s say the code snippet is:
var answer = 6 * 7;
Example AST: https://esprima.org/demo/parse.html
For this code snippet, I have to generate all the paths from leaf to leaf. I can use any parser like esprima, acorn or any other parser.
I am happy to use the python parser as well https://github.com/Kronuz/esprima-python
Any idea, pointers to open source project is welcome.

Related

RobotFramework: Purpose and best practice for the resource- and library-folders

I ponder on purpose and best practice for the Resource- and Library-folders usage in RobotFramework.
Below I have formulated some statements which serves to illustrate my questions. (Abbreviations used: KW = KeyWord, RF = RobotFramework, TS = TestSuite).
Statements/Questions:
Every KW, that is designed to be shared among TS, and written in RF-syntax, should be put inside a .resource-file in the Resource-folder?
Every KW written in Python should be put (as a method inside a .py-file) in the Library-folder?
I.e. the distinction-line between the Resource- and Library-folder is drawn based on syntax used when writing the KW (RF-KW go into Resource-folder and Python-KW go into Libraries-folder).
Or, should the distinction-line rather be drawn upon closeness to the test-rig and system under test. (i.e. High- or Low-level keywords. Where Low-level Keywords are said to be interact with the system under test). And hence you could place python KW (methods) in the Resource-folder?
My take - Yes on everything, even on the last paragraph with the "Or,". Everything up until it were questions on the on the content/syntax of a file. And if your python (library) file has KW-s that make contextual sense to be in a folder with other similar RF (resource) files - place it there.
Remember two things: for Robotframework the distinction between Resource and Library is mainly what syntax it is expecting & how to import the target's resources. It doesn't enforce any rigid expectations on its purpose.
E.g. nothing stops you of having a high-level keyword developed in python like
def login_with_user_and_do_complex_compund_action(user, pass, other_arg)
, nor to create a relatively low-level KW written in Robotframework syntax:
Keyword For Complex Math That Should Better Be In Python
[Arguments] ${complex_number} ${transformer_functuon} ${other_arg}
The other thing is Robotframework is the tool(-set) with which you construct your automated testing framework for the SUT. By your framework I mean the structure & organization of suites and tests, their interconnections and hierarchy, and - the "helpers" for their operations - the before-mentioned resource (RF) and library (py) files.
As long as this framework is logically sound, has established conventions and is easy to grasp & follow, you can have any structure you find suiting you.

Obtaining the QAST of a Perl 6 file from another program

This is related to this question on accesing the POD, but it goes further than that. You can easily access the Abstract Syntax Tree of a Perl 6 program using:
perl6 --target=ast -e '"Þor is mighty!".say'
This will print the whole Q abstract syntax tree. It's not too clear how to make this from your own program, or I haven't found how to do it. In fact, the CoreHackers::Q module runs that as an external script. But being able to access it from your own program, like
use QAST; # It does not exist
my $this-qast = QAST::Load("some-external-file.p6") # Would want something like this
would be great. I'm pretty sure it should be possible, at the NQP level and probably in a Rakudo-dependent way. Does someone know hot it goes?
Since QAST is not a part of the Perl 6 language specification, but an internal implementation detail of Rakudo, there's no official way to do this. Eventually there will be an AST form that is part of the language specification, but that doesn't yet exist (the 007 project which is working on exploring this area).
It is, however, possible to obtain the QAST tree by using:
use nqp;
my $ast = nqp::getcomp("perl6").eval("say 42", :target<ast>);
say $ast.dump();

How to write a custom constraint in the heat template of openstack?

I find I can write anything,like this
constraints:
- custom_constraint:here anything
description: Value must be one of m1.medium, m1.large or m1.xlarge
and in CLI do this WILL BE OK -> heat template-validate -f bad.yaml
And in the document ,just tell you that's a plugin,how should i write a validation plugin????
If you look at the setup.cfg file in the heat source code you will find there is a section that lists the constraints:
heat.constraints =
nova.flavor = heat.engine.clients.os.nova:FlavorConstraint
nova.network = heat.engine.clients.os.nova:NetworkConstraint
...
These reference classes: so if you look at the FlavorConstraint, you will find it in the file heat/heat/engine/clients/os/nova.py
An examination of the class should give you an idea of how to write your own.
That is, if I'm understanding your question (and the code!) correctly.

AFP Dijkstra's Shortest Path Algorithm

For the AFP entry Dijkstra's Shortest Path Algorithm, both the proof outline and proof document were nonexistent *. Unfortunately, I did not find an IsaMakefile either to build those documents locally. What is the best way to get those documents?
Another question, as the Dijkstra.thy depends on a lot of other theories, is there a way to load everything faster?
*) It is fixed now.
(There seems to be something broken at AFP right now, please tell the editors about it.)
In general, you can download the sources of AFP entries and produce the documents yourself like this:
Get and unpack all AFP sources -- downloading separate entries is offered as well, but then you have to disentangle dependencies manually.
Invoke isabelle build like this:
isabelle build -d afp-2013-03-02 -o document=pdf -v Dijkstra_Shortest_Path
Here afp-2013-03-02 is the directory that was obtained by unpacking the current AFP sources.
See also the Isabelle System manual about "Isabelle sessions and build management", which is all new in Isabelle2013.
See isabelle build -b there to make things load faster, by producing persistent heap images from sessions.
The links in the AFP entry were indeed broken and should now be fixed again, sorry about that.
As Makarius writes, the AFP new uses Isabelle's new build system, i.e. has a ROOT file for each entry that can be used to check the associated theories and build the document.
Makarius' answer is pretty much the official way to do it, although I would additionally recommend setting up the AFP as a component. This gives you the following steps:
Download the AFP to e.g. ~/afp
Set it up as component e.g. by adding ~/afp to ~/.isabelle/Isabelle2013/components (see also AFP as a component)
build the entry with
isabelle afp_build Dijkstra_Shortest_Path
You can also have jEdit build the heap image for you. If the AFP is setup as a component (see the other answers for that), just start jEdit with
isabelle jedit -d '$AFP' -l Dijkstra_Shortest_Path
and jEdit will select Dijkstra_Shortest_Path as base logic and (re)build it if necessary.
If you make regular use of the AFP, it might be useful to add the AFP path by default. For this, create a file ROOTS in $ISABELLE_HOME_USER with the line $AFP in it (or add this line, if the file already exists).

A simple AMZI prolog recursion, but is not giving the correct result as expected

So this is my .pro file content (AMZI PROLOG) :
room(kitchen).
room(office).
room(hall).
room('dining room').
room(cellar).
door(office, hall).
door(kitchen, office).
door(hall, 'dining room').
door(kitchen, cellar).
door('dining room', kitchen).
location(desk,office).
location(apple,kitchen).
location(flashlight,desk).
location('washing machine',cellar).
location(nani,'washing machine').
location(broccoli,kitchen).
location(crackers,kitchen).
location(computer,office).
location(envelope,desk).
location(stamp,envelope).
location(key,envelope).
edible(apple).
edible(crackers).
tastes_yucky(broccoli).
here(kitchen).
is_located_in(T1,T2):-location(X,T2),is_located_in(T1,X).
What I want to achieve is that if I use, for example, is_located_in(X,office), then the result will be :
X=desk,
X=flashlight,
X=computer,
X=envelope,
X=stamp,
X=key,
no
(in no particular order).
That way, the result will include things that basically located in / on the object in the office, instead of things that located directly in the office.
This is the source : http://www.amzi.com/AdventureInProlog/a8recurs.php
There is stated that the code are fine, but when I test it, it just returned :
no
Please help. Thanks.
Try this (in this order):
is_located_in(T1,T2):-location(T1,T2).
is_located_in(T1,T2):-location(X,T2),is_located_in(T1,X).

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