How to define predicates using C++ API for CVC4 - c++

This is an example in native CVC language:
isblue: STRING -> BOOLEAN;
ASSERT isblue("sky");
ASSERT isblue("water");
QUERY isblue("sky"); //valid
QUERY isblue("pig"); //invalid
How would I write it using the C++ API for CVC4? Couldn't find any documentation on how to do this.

There are some API examples in the source distribution that might help you. In particular, examples/api/combination.cpp creates some functions and predicates and makes some assertions:
https://github.com/CVC4/CVC4/blob/master/examples/api/combination.cpp
In your case, you'll create a predicate type with ExprManager::mkFunctionType(), then you construct an "isblue" predicate with ExprManager::mkVar() giving it that type. It will look something like this (assuming you've done "using namespace CVC4" and #included <cvc4/cvc4.h>):
ExprManager em;
SmtEngine smt(&em);
Type predType = em.mkFunctionType(em.stringType(), em.booleanType());
Expr isblue = em.mkVar(predType);
Then you can assert and query applications of your predicate:
smt.assertFormula(em.mkExpr(kind::APPLY_UF, isblue, em.mkConst(String("sky"))));
smt.assertFormula(em.mkExpr(kind::APPLY_UF, isblue, em.mkConst(String("water"))));
smt.query(em.mkExpr(kind::APPLY_UF, isblue, em.mkConst(String("sky"))));
smt.query(em.mkExpr(kind::APPLY_UF, isblue, em.mkConst(String("pig"))));

Related

Regex for finding the name of a method containing a string

I've got a Node module file containing about 100 exported methods, which looks something like this:
exports.methodOne = async user_id => {
// other method contents
};
exports.methodTwo = async user_id => {
// other method contents
fooMethod();
};
exports.methodThree = async user_id => {
// other method contents
fooMethod();
};
Goal: What I'd like to do is figure out how to grab the name of any method which contains a call to fooMethod, and return the correct method names: methodTwo and methodThree. I wrote a regex which gets kinda close:
exports\.(\w+).*(\n.*?){1,}fooMethod
Problem: using my example code from above, though, it would effectively match methodOne and methodThree because it finds the first instance of export and then the first instance of fooMethod and goes on from there. Here's a regex101 example.
I suspect I could make use of lookaheads or lookbehinds, but I have little experience with those parts of regex, so any guidance would be much appreciated!
Edit: Turns out regex is poorly-suited for this type of task. #ctcherry advised using a parser, and using that as a springboard, I was able to learn about Abstract Syntax Trees (ASTs) and the recast tool which lets you traverse the tree after using various tools (acorn and others) to parse your code into tree form.
With these tools in hand, I successfully built a script to parse and traverse my node app's files, and was able to find all methods containing fooMethod as intended.
Regex isn't the best tool to tackle all the parts of this problem, ideally we could rely on something higher level, a parser.
One way to do this is to let the javascript parse itself during load and execution. If your node module doesn't include anything that would execute on its own (or at least anything that would conflict with the below), you can put this at the bottom of your module, and then run the module with node mod.js.
console.log(Object.keys(exports).filter(fn => exports[fn].toString().includes("fooMethod(")));
(In the comments below it is revealed that the above isn't possible.)
Another option would be to use a library like https://github.com/acornjs/acorn (there are other options) to write some other javascript that parses your original target javascript, then you would have a tree structure you could use to perform your matching and eventually return the function names you are after. I'm not an expert in that library so unfortunately I don't have sample code for you.
This regex matches (only) the method names that contain a call to fooMethod();
(?<=exports\.)\w+(?=[^{]+\{[^}]+fooMethod\(\)[^}]+};)
See live demo.
Assuming that all methods have their body enclosed within { and }, I would make an approach to get to the final regex like this:
First, find a regex to get the individual methods. This can be done using this regex:
exports\.(\w+)(\s|.)*?\{(\s|.)*?\}
Next, we are interested in those methods that have fooMethod in them before they close. So, look for } or fooMethod.*}, in that order. So, let us name the group searching for fooMethod as FOO and the name of the method calling it as METH. When we iterate the matches, if group FOO is present in a match, we will use the corresponding METH group, else we will reject it.
exports\.(?<METH>\w+)(\s|.)*?\{(\s|.)*?(\}|(?<FOO>fooMethod)(\s|.)*?\})
Explanation:
exports\.(?<METH>\w+): Till the method name (you have already covered this)
(\s|.)*?\{(\s|.)*?: Some code before { and after, non-greedy so that the subsequent group is given preference
(\}|(?<FOO>fooMethod)(\s|.)*?\}): This has 2 parts:
\}: Match the method close delimiter, OR
(?<FOO>fooMethod)(\s|.)*?\}): The call to fooMethod followed by optional code and method close delimiter.
Here's a JavaScript code that demostrates this:
let p = /exports\.(?<METH>\w+)(\s|.)*?\{(\s|.)*?(\}|(?<FOO>fooMethod)(\s|.)*?\})/g
let input = `exports.methodOne = async user_id => {
// other method contents
};
exports.methodTwo = async user_id => {
// other method contents
fooMethod();
};
exports.methodThree = async user_id => {
// other method contents
fooMethod();
};';`
let match = p.exec( input );
while( match !== null) {
if( match.groups.FOO !== undefined ) console.log( match.groups.METH );
match = p.exec( input )
}

Query parameters for GET requests using Akka HTTP (formally known as Spray)

One of the features of Akka HTTP (formally known as Spray) is its ability to automagically marshal and unmarshal data back and forth from json into case classes, etc. I've had success at getting this to work well.
At the moment, I am trying to make an HTTP client that performs a GET request with query parameters. The code currently looks like this:
val httpResponse: Future[HttpResponse] =
Http().singleRequest(HttpRequest(
uri = s"""http://${config.getString("http.serverHost")}:${config.getInt("http.port")}/""" +
s"query?seq=${seq}" +
s"&max-mismatches=${maxMismatches}" +
s"&pam-policy=${pamPolicy}"))
Well, that's not so pretty. It would be nice if I could just pass in a case class containing the query parameters, and have Akka HTTP automagically generate the query parameters, kind of like it does for json. (Also, the server side of Akka HTTP has a somewhat elegant way of parsing GET query parameters, so one would think that it would also have a somewhat elegant way to generate them.)
I'd like to do something like the following:
val httpResponse: Future[HttpResponse] =
Http().singleRequest(HttpRequest(
uri = s"""http://${config.getString("http.serverHost")}:${config.getInt("http.port")}/query""",
entity = QueryParams(seq = seq, maxMismatches = maxMismatches, pamPolicy = pamPolicy)))
Only, the above doesn't actually work.
Is what I want doable somehow with Akka HTTP? Or do I just need to do things the old-fashioned way? I.e, generate the query parameters explicitly, as I do in the first code block above.
(I know that if I were to change this from a GET to a POST, I could probably to get it to work more like I would like it to work, since then I could get the contents of the POST request automagically converted from a case class to json, but I don't really wish to do that here.)
You can leverage the Uri class to do what you want. It offers multiple ways to get a set of params into the query string using the withQuery method. For example, you could do something like this:
val params = Map("foo" -> "bar", "hello" -> "world")
HttpRequest(Uri(hostAndPath).withQuery(params))
Or
HttpRequest(Uri(hostAndPath).withQuery(("foo" -> "bar"), ("hello" -> "world")))
Obviously this could be done by altering the extending the capability of Akka HTTP, but for what you need (just a tidier way to build the query string), you could do it with some scala fun:
type QueryParams = Map[String, String]
object QueryParams {
def apply(tuples: (String, String)*): QueryParams = Map(tuples:_*)
}
implicit class QueryParamExtensions(q: QueryParams) {
def toQueryString = "?"+q.map{
case (key,value) => s"$key=$value" //Need to do URL escaping here?
}.mkString("&")
}
implicit class StringQueryExtensions(url: String) {
def withParams(q: QueryParams) =
url + q.toQueryString
}
val params = QueryParams(
"abc" -> "def",
"xyz" -> "qrs"
)
params.toQueryString // gives ?abc=def&xyz=qrs
"http://www.google.com".withParams(params) // gives http://www.google.com?abc=def&xyz=qrs

Regex JSON response Gatling stress tool

Wanting to capture a variable called scanNumber in the http response loking like this:
{"resultCode":"SUCCESS","errorCode":null,"errorMessage":null,"profile":{"fullName":"TestFirstName TestMiddleName TestLastName","memberships":[{"name":"UA Gold Partner","number":"123-456-123-123","scanNumber":"123-456-123-123"}]}}
How can I do this with a regular experssion?
The tool I am using is Gatling stress tool (with the Scala DSL)
I have tried to do it like this:
.check(jsonPath("""${scanNumber}""").saveAs("scanNr")))
But I get the error:
---- Errors --------------------------------------------------------------------
> Check extractor resolution crashed: No attribute named 'scanNu 5 (100,0%)
mber' is defined
You were close first time.
What you actually want is:
.check(jsonPath("""$..scanNumber""").saveAs("scanNr")))
or possibly:
.check(jsonPath("""$.profile.memberships[0].scanNumber""").saveAs("scanNr")))
Note that this uses jsonPath, not regular expressions. JsonPath should more reliable than regex for this.
Check out the JsonPath spec for more advanced usage.
use this regex to match this in anywhere in json:
/"scanNumber":"[^"]+"/
and if you want to match just happens in structure you said use:
/\{[^{[]+\{[^{[]+\[\{[^{[]*("scanNumber":"[^"]+")/
Since json fields may change its order you should make your regex more tolerant for those changes:
val j = """{"resultCode":"SUCCESS","errorCode":null,"errorMessage":null,"profile":{"fullName":"TestFirstName TestMiddleName TestLastName","memberships":[{"name":"UA Gold Partner","number":"123-456-123-123","scanNumber":"123-456-123-123"}]}}"""
val scanNumberRegx = """\{.*"memberships":\[\{.*"scanNumber":"([^"]*)".*""".r
val scanNumberRegx(scanNumber) = j
scanNumber //String = 123-456-123-123
This will work even if the json fields will be in different order (but of course keep the structure)

Configuring C# out parameters with Foq in F#

I am using F# and Foq to write unit tests for a C# project.
I am trying to set up a mock of an interface whose method has an out parameter, and I have no idea how to even start. It probably has to do with code quotations, but that's where my understanding ends.
The interface is this:
public interface IGetTypeNameString
{
bool For(Type type, out string typeName);
}
In C# Foq usage for the interface looks like this:
[Fact]
public void Foq_Out()
{
// Arrange
var name = "result";
var instance = new Mock<IGetTypeNameString>()
.Setup(x => x.For(It.IsAny<Type>(), out name))
.Returns(true)
.Create();
// Act
string resultName;
var result = instance.For(typeof(string), out resultName);
// Assert
Assert.True(result);
Assert.Equal("result", resultName);
}
As for how to achieve that with F#, I am completely lost. I tried something along the lines of
let name = "result"
let instance = Mock<IGetTypeNameString>().Setup(<# x.For(It.IsAny<Type>(), name) #>).Returns(true).Create();
which results in the quotation expression being underlined with an error message of
This expression was expected to have type IGetTypeNameString -> Quotations.Expr<'a> but here has type Quotations.Expr<'b>
Without any indication what types a and b are supposed to be, I have no clue how to correct this.
:?>
(It gets even wilder when I use open Foq.Linq; then the Error List window starts telling me about possible overloads with stuff like Action<'TAbstract> -> ActionBuilder<'TAbstract>, and I get even loster....)
Any assistance or explanation greatly appreciated!
Edit:
So, as stated here, byref/out parameters can not be used in code quotations. Can this be set up at all then in F#?
Foq supports setting up of C# out parameters from C# using the Foq.Linq namespace.
The IGetTypeNameString interface can be easily setup in F# via an object expression:
let mock =
{ new IGetTypeNameString with
member __.For(t,name) =
name <- "Name"
true
}
For declarations that have no analog in F#, like C#'s protected members and out parameters, you can also use the SetupByName overload, i.e.:
let mock =
Mock<IGetTypeNameString>()
.SetupByName("For").Returns(true)
.Create()
let success, _ = mock.For(typeof<int>)

Adding SignedDataObjects (and consequently add proofOfApproval property) to an enveloped signature

I'm creating an Enveloped signature with xades4j following this statements:
Element elemToSign = doc.getDocumentElement();
XadesSigner signer = new XadesTSigningProfile(...).newSigner();
new Enveloped(signer).sign(elemToSign);
But I need to put in the signature also other properties like ProofOfApprova etc...
I see that in xades4j examples the proofOfApprovalProperties are addedto enveloped signature using different statements of signature, for example:
AllDataObjsCommitmentTypeProperty globalCommitment = AllDataObjsCommitmentTypeProperty.proofOfApproval();
CommitmentTypeProperty commitment = CommitmentTypeProperty.proofOfCreation();
DataObjectDesc obj1 = new DataObjectReference('#' + elemToSign.getAttribute("Id"))
.withTransform(new EnvelopedSignatureTransform())
.withDataObjectFormat(new DataObjectFormatProperty("text/xml", "MyEncoding")
.withDescription("Isto é uma descrição do elemento raiz")
.withDocumentationUri("http://doc1.txt")
.withDocumentationUri("http://doc2.txt"))
.withIdentifier("http://elem.root"))
.withCommitmentType(commitment)
.withDataObjectTimeStamp(dataObjsTimeStamp)
SignedDataObjects dataObjs = new SignedDataObjects(obj1)
.withCommitmentType(globalCommitment);
signer.sign(dataObjs, elemToSign);
I see here that another procedure of signature is used, more specificately the statement in which I create a DataObjectreference saying that I use "Id" attibute fo root tag is unusable for me because in input I can have any kind of xml document and I cannot know what kind of attribute (if present) I can use foe define root tag.
Briefly, can I have some examp'le code where I create an Enveloped signature and put a proofOfApproval property using "new Enveloped(signer).sign(elemToSign);", or anyway whitout knowing the xml source structure?
Thanks
M.
The proofOfApproval property has to be applied to data objects being signed, hence the need to use the SignedDataObjects class.
The Enveloped class is just a helper for straightforward scenarios. If I understood correctly you want to sign the whole XML document. The XML-Signatures spec defines that an empty URI on a reference (URI="") means exactly that. If you check the code on the Enveloped class you'll see that it adds a DataObjectReference with an empty uri.
To sum up, you'll need something like:
DataObjectDesc obj1 = new DataObjectReference("")
.withTransform(new EnvelopedSignatureTransform())
.withCommitmentType(CommitmentTypeProperty.proofOfApproval());
signer.sign(new SignedDataObjects(obj1), elemToSign);