I would like to define a set of coding rules of a language structural proprietary language,
how can I proceed?
thank you very much
Some of your rules will be easy to deal with using only parsing. For example to find the number of lines in a function is not hard:
void function() : {
int firstLine, lastLine ; }
{
{firstLine = getToken(1).beginLine ; }
...
{lastLine = getToken(0).beginLine ; }
{check( lastLine - firstLine + 1 <= 150 ) ; }
}
Other rules, such as your example of nested ifs, will be best handled by traversing an abstract syntax tree. I'd suggest you look into JJTree. It supports visitors, which could be quite useful for encoding some of your rules.
If I have understood correctly,
in the file .jj, I have to add this function , which allows to check how many line of code in a method
or in the file parseur.java generated by javacc.
Related
I want to write a script which compare two files in java and see there difference in html page ( side by side ), can someone help me out how to write ( where to start). I am pulling my hair out for this....
I want to use this script in beanshell postprocessor so that I can compare the standard output files with result files easily
I don't think you should be asking people for writing code for you here, consider hiring a freelancer instead.
Alternatively you can use the following approach:
Add JSR223 Assertion as a child of the request which you would like to fail if files won't be equal
Put the following code into "Script" area:
def file1 = new File('/path/to/file1')
def file2 = new File('/path/to/file2')
def file1Lines = file1.readLines('UTF-8')
def file2Lines = file2.readLines('UTF-8')
if (file1Lines.size() != file2Lines.size()) {
AssertionResult.setFailure(true)
AssertionResult.setFailureMessage('Files size is different, omitting line-by-line compare')
} else {
def differences = new StringBuilder()
file1Lines.eachWithIndex {
String file1Line, int number ->
String file2Line = file2Lines.get(number)
if (!file1Line.equals(file2Line)) {
differences.append('Difference # ').append(number).append('. Expected: ')
.append(file1Line).append('. Actual: ' + file2Line)
differences.append(System.getProperty('line.separator'))
}
}
if (differences.toString().length() > 0) {
AssertionResult.setFailure(true)
AssertionResult.setFailureMessage(differences.toString())
}
}
If there will be differences in files content you will see them listed one by one in the JSR223 Assertion
See Scripting JMeter Assertions in Groovy - A Tutorial for more details.
I'm coming from C++ background, trying to make use of it for R OOP programming with R6 package.
Consider the following typical situation when writing a large OOP code. -
You have a class, in which you have several (possibly many) functions, each of which may also be quite complex and with many lines of code:
# file CTest.R
cTest <- R6Class(
"CTest",
public = list(
z = 10,
fDo1 = function() {
# very long and complex code goes here
self$z <- self$z*2; self$z
},
fDo2 = function() {
# another very long and complex code goes here
print(self)
}
)
) #"CTest"
Naturally, you don't want to put ALL your long and various functions in the same (CTest.R) file - it will become messy and unmanageable.
If you program in C++, normal way to program such code is : first, you declare you functions in .h file, then you create .c files for each you complex function, where you define your function. This makes it possible to do collaborative code writing, including efficient source-control.
So, I've tried to do something similar in R, like: first, declaring a function as in code above, and then, trying to assign the "actual long and complex" code to it later (which later I would put in a separate file CTest-Do1.R):
cTest$f <- function() {
self$z <- self$z*100000; self$z
}
Now I test if it works:
> tt <- cTest$new(); tt; tt$fDo1(); tt
<CTest>
Public:
clone: function (deep = FALSE)
fDo1: function ()
fDo2: function ()
z: 10
[1] 20
<CTest>
Public:
clone: function (deep = FALSE)
fDo1: function ()
fDo2: function ()
z: 20
No, it does not.- As seen from output above, the function has not been changed.
Any advice?
Thanks to Grothendieck's comment above, there's a reasonable workaround to make it work.
Instead of this:
# CTest-Do1_doesnotwork.R
cTest$fDo1 <- function() {
...
}
write this:
# CTest-Do1_works.R
cTest$set(
overwrite = TRUE, "public", "fDo1",
function() {
...
}
)
This code can now be written in separate file, as originally desired.
I still wonder though - Is the above describe way actually the common(best) practice for writing large OOP codes in R community? (looks a bit strange to me).
If not, what is it (beyond just using source()) ? - so that to enable collaborative coding and source control for separate parts (functions) of a class ?
I came here also searching for R6 best practice. One way that I've seen (here) is to define the functions elsewhere as normal R functions and pass in self, private etc as required
cTest<- R6::R6Class("CTest",
public = list(
fDo1 = function()
cTestfDo1(self),
fDo2 = function(x)
cTestfDo2(self, private, x)
))
and else where have
cTestfDo1 <- function(self) {
self$z <- self$z*2; self$z
}
and somewhere else
cTestfDo2 <- function(self, private, x) {
self$z * private$q + x
}
etc
I don't know if it's best practice, or efficient, but the class definition looks neat with it and if the cTestfDo1 functions are not exported then it's relatively neat in the namespace too.
I have some code that generates gremlin traversals dynamically based on a query graph that a user supplies. It generates gremlin that relies heavily on backtracking. I've found some edge cases that are generating gremlin that doesn't do what I expected it to, but I also can't find anything online about the rules surrounding the usage of some of these pipes (like 'as' and 'back' in this case). An example of one of these edge cases:
g.V("id", "some id").as('1').inE("edgetype").outV.has("#class", "vertextype").as('2').inE("edgetype").outV.has("#class", "vertextype").filter{(it.getProperty("name") == "Bob")}.outE("edgetype").as('target').inV.has("id", "some id").back('2').outE("edgetype").inV.has("id", "some other id").back('target')
The goal of the traversal is to return the edges that were 'as'd as 'target'. When I run this against my orientdb database it encounters a null exception. I narrowed down the exception to the final pipe in the traversal: back('target'). I'm guessing that the order of the 'as's and 'back's matters and that the as('target') went 'out of scope' as soon as back('2') was executed. So a few questions:
Is my understanding (that 'target' goes out of scope because I backtracked to before it was 'as'd) correct?
Is there anywhere I can learn the rules surrounding backtracking without having to reverse engineer the gremlin source?
edit:
I found the relevant source code:
public static List<Pipe> removePreviousPipes(final Pipeline pipeline, final String namedStep) {
final List<Pipe> previousPipes = new ArrayList<Pipe>();
for (int i = pipeline.size() - 1; i >= 0; i--) {
final Pipe pipe = pipeline.get(i);
if (pipe instanceof AsPipe && ((AsPipe) pipe).getName().equals(namedStep)) {
break;
} else {
previousPipes.add(0, pipe);
}
}
for (int i = 0; i < previousPipes.size(); i++) {
pipeline.remove(pipeline.size() - 1);
}
if (pipeline.size() == 1)
pipeline.setStarts(pipeline.getStarts());
return previousPipes;
}
It looks like the BackFilterPipe does not remove any of the aspipes between the back pipe and the named as pipe, but they must not be visible to pipes outside the BackFilterPipe. I guess my algorithm for generating the code is going to have to be smarter about detecting when the target is within a meta pipe.
Turns out the way I was using 'as' and 'back' made no sense. When you consider that everything between the 'back('2')' and the 'as('2')' is contained within the BackFilterPipe's inner pipeline, it becomes clear that meta pipes can't be overlapped like this: as('2'), as('target'), back('2'), back('target').
Is it possible to specify MXML-esque "binding strings" in ActionScript?
For example, I want to be able to do something like:
MXMLBinding(this, "first_item",
this, "{myArrayCollection.getItemAt(0)");
MXMLBinding(this, ["nameLbl", "text"],
this, "Name: {somePerson.first} {somePerson.last}");
Edit: thanks for the responses and suggestions… Basically, it seems like you can't do this. I've dug around and figured out why.
(Shameless plug)
BindageTools can do this:
Bind.fromProperty(this, "myArrayCollection", itemAt(0))
.toProperty(this, "first_item");
Bind.fromAll(
Bind.fromProperty(this, "somePerson.first"),
Bind.fromProperty(this, "somePerson.last")
)
.format("Name: {0} {1}")
.toProperty(this, "nameLbl.text");
Note that BindageTools puts the source object first and the destination last (whereas BindingUtils puts the destination first and the source last).
Using ChangeWatcher (e.g., via BindingUtils.bindProperty or .bindSetter) is the way to go, yes. I admit it's a strange notation, but once you get used to it, it makes sense, works perfectly and is quite flexible, too.
Of course, you could always wrap those functions yourself somehow, if the notation bugged you -- both methods are static, so doing so in a way that feels more appropriate to your application should be a fairly straightforward exercise.
I could use BindingUtils or ChainWatcher, but then I'd end up with code that looks something like this:
…
BindingUtils.bindSetter(updateName, this, ["somePerson", "first"]);
BindingUtils.bindSetter(updateName, this, ["somePerson", "last"]);
…
protected function updateName(...ignored):void {
this.nameLbl.text = "Name: " + somePerson.first + " " + somePerson.last;
}
Which is just a little bit ugly… And the first example, binding to arrayCollection.getItemAt(0), is even worse.
Does the first parameter (function) of BindingUtils.bindSetter method accept anonymous methods?
BindingUtils.bindSetter(function()
{
this.nameLbl.text = "Name: " + somePerson.first + " " + somePerson.last;
}, this, ["somePerson", "last"]);
I hate anonymous methods and obviously it's even more uglier - so I won't recommend that even if it works, but just wondering if it works.
Never the answer anyone wants to hear, but just manage this stuff with getters/setters in ActionScript. With a proper MVC, it's dead simple to manually set your display fields.
public function set myArrayCollection(value:Array):void {
myAC = new ArrayCollection(value);
first_item = mcAC.getItemAt(0); // or value[0];
}
etc....
Alright, so I've done some digging, and here's what's up.
Bindings in MXML are, contrary to reason, setup by Java code (modules/compiler/src/java/flex2/compiler/as3/binding/DataBindingFirstPassEvaluator.java, if I'm not mistaken) at compile time.
For example, the binding: first_item="{myArrayCollection.getItemAt(0)}"` is expanded into, among other things, this:
// writeWatcher id=0 shouldWriteSelf=true class=flex2.compiler.as3.binding.PropertyWatcher shouldWriteChildren=true
watchers[0] = new mx.binding.PropertyWatcher("foo",
{ propertyChange: true }, // writeWatcherListeners id=0 size=1
[ bindings[0] ],
propertyGetter);
// writeWatcher id=1 shouldWriteSelf=true class=flex2.compiler.as3.binding.FunctionReturnWatcher shouldWriteChildren=true
watchers[1] = new mx.binding.FunctionReturnWatcher("getItemAt",
target,
function():Array { return [ 0 ]; },
{ collectionChange: true },
[bindings[0]],
null);
// writeWatcherBottom id=0 shouldWriteSelf=true class=flex2.compiler.as3.binding.PropertyWatcher
watchers[0].updateParent(target);
// writeWatcherBottom id=1 shouldWriteSelf=true class=flex2.compiler.as3.binding.FunctionReturnWatcher
// writeEvaluationWatcherPart 1 0 parentWatcher
watchers[1].parentWatcher = watchers[0];
watchers[0].addChild(watchers[1]);
This means that it is simply impossible to setup curly-brace MXML-style bindings at runtime because the code to do it does not exist in ActionScript.
First question from a long time user.
I'm writing a Perl script that will go through a number of HTML files, search them line-by-line for instances of "color:" or "background-color:" (the CSS tags) and print the entire line when it comes across one of these instances. This is fairly straightforward.
Now I'll admit I'm still a beginning programmer, so this next part may be extremely obvious, but that's why I came here :).
What I want it to do is when it finds an instance of "color:" or "background-color:" I want it to trace back and find the name of the element, and print that as well. For example:
If my document contained the following CSS:
.css_class {
font-size: 18px;
font-weight: bold;
color: #FFEFA1;
font-family: Arial, Helvetica, sans-serif;
}
I would want the script to output something like:
css_class,#FFEFA1
Ideally it would output this as a text file.
I would greatly appreciate any advice that could be given to me regarding this!
Here is my script in full thus far:
$color = "color:";
open (FILE, "index.html");
#document = `<FILE>`;
close (FILE);
foreach $line (#document){
if($line =~ /$color/){
print $line;
}
}
Since you asked for advice (and this isn't a coding service) I'll offer just that.
Always use strictures and warnings:
use strict;
use warnings;
Always check the return value of open calls:
open(FILE, 'filename') or die "Can't read file 'filename' [$!]\n";
Use the three-arg form of open and lexical filehandles instead of globs:
open(my $fh, '<', 'filename') or die "Can't read file 'filename' [$!]\n";
Don't slurp when line-by-line processing will do:
while (my $line = <$fh>) {
# do something with $line
}
Use backreferences to retrieve data from regex matches:
if ($line =~ /color *: *(#[0-9a-fA-F]{6})/) {
# color value is in $1
}
Save the class name in a temporary variable so that you have it when you match a color:
if ($line =~ /^.(\w+) *\{/) {
$class = $1;
}
Well, this is not as simple as it seems.
CSS classes can be defined in many ways. For example,
.classy {
color: black;
}
Good luck using a line-by-line approach for parsing that.
Actually, my first approach would be searching CPAN. This looks promising:
CSS - Object oriented access to Cascading Style Sheets (CSS)
Edit:
I installed HTML::TreeBuilder and CSS modules from CPAN and concocted the following aberration:
use strict;
use HTML::TreeBuilder;
use CSS;
foreach my $file_name (#ARGV) {
my $tree = HTML::TreeBuilder->new; # empty tree
$tree->parse_file($file_name);
my $styles = $tree->find('style');
if ($styles) {
foreach my $style ($styles) {
# This is an insane hack, not guarantee
# to work in the future.
my $css = CSS->new;
$css->read_string(join "\n", #{$style->{_content}});
print $css->output;
}
}
$tree = $tree->delete;
}
This thing only prints all the CSS selectors from list of HTML files, but nicely formatted so you should be able to continue from here.
For yet another way to do it, you can ask perl to read from the file in sections other than lines, for example by using the "}" as a record separator.
my $color = "color:";
open (my $fh, '<', "index.html") || die "Can't open file: $!";
{
local $/ = "}";
while( my $section = <$fh>) {
if($section =~ /$color(.*)/) {
my ($selector) = $line =~ /(.*){/;
print "$selector, $section\n";
}
}
Untested! Also, this of course assumes that your CSS neatly ends its sections with a } on a line on it's own.
I'm not having problems with the regex's but rather with the capture of data. Since CSS elements are typically multi-line, I need to figure out how to create an array between the { and } with each linebreak as a delimiter for list items.
No, you don't.
For the problem as stated, the only lines of interest will be those containing either a class name or a color definition, and possibly also lines containing } to mark the end of a class. All other lines can be ignored, so there's no need to put them into an array.
Since class specifications cannot be nested[1], the last seen set of class names will always be the active set of classes. Therefore, you need only record the last seen set of class names and, when a color specification is encountered, print those class names.
There are still some potential difficulties handling cases in which a specification block is shared by multiple classes (.foo, .bar, .baz { ... }), which may or may not be spread across multiple lines, or if multiple attributes are defined on the same line, but dealing with those should follow fairly easily from what I've already laid out. Depending on your input data, you may also need to include a basic state engine to keep track of whether you're in comments or not.
[1] i.e., Although you can have semantically-nested classes, such as .foo and .foo .bar, they have to be specified in the CSS file as
.foo {
...
}
.foo .bar {
...
}
and cannot be
.foo {
...
.bar {
...
}
}
Although I have not tested the code below, but something like this should work:
if ($line =~ m/\.(.*?) \{(.*?)color:(.*?);(.*)/) {
print "$1,$3\n";
}
You should invest some time learning regular expressions for Perl.