Until now my parser is able to parse functions with a known parameter number using expressions such as this
<FUNCTION><OPENPAR> son=expression() <COMMA> son1=expression() <CLOSEPAR>
Also, optional parameters can also easily be handled
<FUNCTION><OPENPAR> son=expression() <COMMA> son1=expression() [<COMMA> son2=expression()] <CLOSEPAR>
However, I haven't been able to find documentation regarding the possibility of capturing an unknown number of parameters. My guess is something like this
<FUNCTION><OPENPAR> son=expression() <COMMA> son1=expression() [<COMMA> son2=expression()]+ <CLOSEPAR>
But in this case I don't know how to capture of these multiple parameters should be done.
Any ideas or examples? (or if anyone knows that this is impossible)
Let's say at least one parameter is required. Then, you would need something like:
private X myFunction():
{
X result = new X();
}
{
<FUNCTION>
<OPENPAR>
son=expression() { result.params.add(son); }
( <COMMA> son=expression() { result.params.add(son); } )*
<CLOSEPAR>
{ return result; }
}
To sum up, my approach is to:
Create result Java class X and use it as you would in plain Java.
Initialize what's required at the beginning.
Return filled object.
If you still need working example, you may find this useful.
Related
In Cucumber 7.4.1+ TypeRegistry is deprecated in favour of annotations.
Indeed, as of today, I have never used anything but #ParameterType to define my ParameterTypes. Searching for alternatives, TypeRegistry is the only one I have found - but if it is "on the way out", of course I'd rather not start using it now.
Given a construct like this I cannot use annotations because those cannot take static parameters:
enum SpecialDate implements Supplier<Date> {
TODAY { #Override public Date get() { return Date(); } },
// YESTERDAY, etc.
;
static String typeSafeRegEx() {
return Arrays.stream(Zeitpunkt.values())
.map(SpecialDate::specName)
.collect(Collectors.joining("|"));
}
static SpecialDate from(final String specName) {
return valueOf(StringUtils.upperCase(specName));
}
String specName() {
return StringUtils.capitalize(StringUtils.lowerCase(this.name()));
}
}
public class ParameterTypes {
// does not compile: "Attribute value must be constant"
#ParameterType("(" + SpecialDate.typeSafeRegEx() + ")")
public Date specialDate(final String specName) {
return SpecialDate.from(specName).get();
}
}
A so-specified regEx is nice, because it will only match values guaranteed to be mappable, so I need no additional error handling code beyond Cucumber's own. The list of allowed values is also maintenance-free (compared to a "classic" switch which would silently grow incorrect when adding new values).
The alternative would be to use an unsafe switch + default: throw, strictly worse because it has to be maintained manually.
(Or, I guess, to just valueOf whatever + wrap into a more specific exception, when it eventually fails.)
To me, Cucumber's native UndefinedStepException appears to be the best outcome on a mismatch, because everyone familiar with Cucumber will immediately recognise it, unlike a project-specific one.
I see that e.g. the ParameterType class is not deprecated but cannot seem to find information how to use it without TypeRegistry.
FWIW:
Updating the libraries or Java would not be an issue. (But downgrading is sadly not viable.)
Business Specialists want to write examples like [Today], [Today + 1], [Yesterday - 3], etc. If this can be realised more elegantly using a different approach, X/Y answers would also be welcome.
An example step looks like this:
And I enter into the field 'Start of Implementation' the <begin>
Examples:
| begin
| [Today]
| [Today + 1]
I'm working in Java and trying to determine something like so:
I have a SqlParameterSource with an array named "ids" in it. I need to determine what type these ids are in, for example numeric or varchar. I specify that earlier in the code with for example:
return con.createArrayOf("varchar")
or
return con.createArrayOf("numeric")
I have tried this:
if (parametersource.getSqlType("ids") == something) {
// do something
}
else {
//do something else
}
I can't figure out how to do this. getSqlType seems to return an int but I don't know what to compare it to to get the correct comparison.
There is another method named getTypeName but I don't get how this works.
I solved it with:
parameterSource.getValue("objtype").toString();
Fetches the value from "objtype" which I set in my ParameterSource alongside my array to make my end goal easier.
Thanks friends, I love you all. :)
If you're talking about Spring SqlParameterSource,try parametersource.getTypeName("ids")which is inherited from AbstractSqlParameterSource
imagine this:
DataTypeForConfigs config
with
String keys, but values of either String, Integer, or Boolean,
in Java, JSON can do that, but I'm making a format That goes along the lines of:
number "coolness" is 9001 means
int coolness = 9001;
It's method is: Read line, read each word, think what to make of it, set it to a Variable within it's reach
Also: what would happen if another thing had its own place to put config? a null would be read? WHY? constructor thinks a file has null on it? Rage face.
Say... should I make a class called SettingVal that when given a getValue() call it would say what it is?
SO:
config["Coolness"].getValue();
return's 9001
WAIT:
How on earth would I make the getValue() method? HOW? RETURN VALUE WONT LIKE THIS!! OH CRAP!
Solution:
Another Data type comes in and checks its 'gender' (String, Bool, Int) and then checks it's value of that 'gender' (strVal, boolVar, intVar)
Return values are a big problem when dealing with this. I need a stress free version, so maybe I can have a void returning method that runs another method based on what data type it is said to hold! Am I right?
I have a temporary solution, setVar works, getVar is get*Var, where * is Str, Bool or Int.
Sadly, I Haven't yet been able to properly read it from a file, the method I made to read from a file is not working. It makes a Map<String,SettingVar>, using a HashMap constructor and returns that map, but seems whenever I try to access a variable from it that variable is null. It is probably because of IOExceptions and FileNotFoundExceptions, FileNotFound? Why? It Shouldn't be running until called. Oh, and also NullPointerExceptions Please Help!
SUBQUESTION: what happens when you MapVariable.put({NAME HERE}, varToPutIn) many times in a for loop? what about MapVariable.put({NAME HERE},new ...)?
My code in links:
https://gist.github.com/anonymous/66c4d1c2d2718a4cc9b9
because I don't have enough reputation
P.S: OK! ive made the config reader work now, and SettingVar, and SettingContainer and im working on ConfigWriter which is good, now working on a prototype for a java command prompt like thing, and soon a WHOLE OS!! wait... java is an os. thats why java virtual machine... oh. Well, how can I close this question and turn the outcome into a revolutionary new thingy for kids who want to learn to code java *cough cough* especialy ones with higher learning ability than social ability... and like to hang around with mature people who dont bully them like all the kids in their school. (Wow, that was specific)
I would use a Plain Old Java Object which you can read from JSON.
class Config {
int coolness = 9001;
String hello = "world";
boolean cool = true;
}
This way you can have fields with a variety of types.
The type you're looking for is Map<String,Object>, but it is not type-safe and you'll have to do a bunch of casting:
Map<String,Object> config = new HashMap<>();
config.put("coolness",9001);
config.put("hello","world");
config.put("cool", true);
boolean cool = (Boolean) config.get("cool");
String hello = (String) config.get("world");
int coolness = (Integer) config.get("coolness");
Generally, I'd recommend creating a dedicated class for holding your configuration (each field = one property), which is strongly typed and doesn't require casting, and then use something like Jackson to serialize/deserialize it from json, yaml, or xml.
This provides structure to your configuration, and will cause any issues with malformed configurations to show up when you start your application/load your configuration, and not in the middle of your application.
SUBQUESTION: what happens when you MapVariable.put(varToPutIn) many times in a for loop?
A Map represents a mapping. If you do this:
Map<String, Object> map = new HashMap<>();
for (int i = 0; i < 10; i++) {
map.put("myKey", Integer.valueOf(i));
}
what happens is that you add a mapping from "myKey" to zero, then update it to one, two, three and so on. When the loop ends, "myKey" will map to nine.
In short, the map entry for "myKey" is behaving like a variable of type Integer that you assign to repeatedly.
I'm afraid your Gists are telling me that you simply didn't take on board what #Darth Android wrote. Rather that hashing through your code, here's a simple way to parse your config file syntax (more or less) and load it into a Map<String, Object>
Note: I have not compiled or tested this code. It is written to be read and understood, rather than borrowed.
Map<String,Object> config = new HashMap<>();
try (Scanner s = new Scanner(new FileReader(someFile))) {
while (s.hasNext()) {
// Syntax is '<type> <name> is <value>'
String[] words = s.nextLine().split("\\s+");
if (words.length != 4 || !words[2].equals("is")) {
throw MySyntaxException("unrecognizable config");
}
String type = words[0];
String name = words[1];
String val = words[3];
switch (type) {
case "number":
map.put(name, Integer.valueOf(val));
break;
case "boolean":
map.put(name, Boolean.valueOf(val));
break;
case "string":
map.put(name, val);
break;
default:
throw MySyntaxException("unknown type");
}
} catch (NumberFormatException ex) {
throw MySyntaxException("invalid number");
}
}
I'm trying to read in a csv in the hdfs, parse it with cascading, and then use the resulting tuple stream to form the basis of regex expressions in another tuple stream using RegexParser. As far as I can tell, the only way to do this would be to write a custom Function of my own, and I was wondering if anybody knew how to use the Java API to do this instead.
Pointers on how to write my own function to do this inside the cascading framework would be welcome, too.
I'm running Cascading 2.5.1
The best resource for this question is the Palo Alto cascading example tutorial. It's in java and provides examples of a lot of use cases, including writing custom functions.
https://github.com/Cascading/CoPA/wiki
And yes, writing a function that allows an input regex that references other argument inputs is your best option.
public class SampleFunction extends BaseOperation implements Function
{
public void operate( FlowProcess flowProcess, FunctionCall functionCall )
{
TupleEntry argument = functionCall.getArguments();
String regex = argument.getString( 0 );
String argument = argument.getString( 1 );
String parsed = someRegexOperation();
Tuple result = new Tuple();
result.add( parsed );
functionCall.getOutputCollector().add( result );
}
}
I'm not having any luck getting Mockito to capture function argument values! I am mocking a search engine index and instead of building an index, I'm just using a hash.
// Fake index for solr
Hashmap<Integer,Document> fakeIndex;
// Add a document 666 to the fakeIndex
SolrIndexReader reader = Mockito.mock(SolrIndexReader.class);
// Give the reader access to the fake index
Mockito.when(reader.document(666)).thenReturn(document(fakeIndex(666))
I can't use arbitrary arguments because I'm testing the results of queries (ie which documents they return). Likewise, I don't want to specify a specific value for and have a line for each document!
Mockito.when(reader.document(0)).thenReturn(document(fakeIndex(0))
Mockito.when(reader.document(1)).thenReturn(document(fakeIndex(1))
....
Mockito.when(reader.document(n)).thenReturn(document(fakeIndex(n))
I looked at the callbacks section on the Using Mockito page. Unfortunately, it isn't Java and I couldn't get my own interpretation of that to work in Java.
EDIT (for clarification):
How do I get get Mockito to capture an argument X and pass it into my function? I want the exact value (or ref) of X passed to the function.
I do not want to enumerate all cases, and arbitrary argument won't work because I'm testing for different results for different queries.
The Mockito page says
val mockedList = mock[List[String]]
mockedList.get(anyInt) answers { i => "The parameter is " + i.toString }
That's not java, and I don't know how to translate into java or pass whatever happened into a function.
I've never used Mockito, but want to learn, so here goes. If someone less clueless than me answers, try their answer first!
Mockito.when(reader.document(anyInt())).thenAnswer(new Answer() {
public Object answer(InvocationOnMock invocation) {
Object[] args = invocation.getArguments();
Object mock = invocation.getMock();
return document(fakeIndex((int)(Integer)args[0]));
}
});
Check out ArgumentCaptors:
https://site.mockito.org/javadoc/current/org/mockito/ArgumentCaptor.html
ArgumentCaptor<Integer> argument = ArgumentCaptor.forClass(Integer.class);
Mockito.when(reader.document(argument.capture())).thenAnswer(
new Answer() {
Object answer(InvocationOnMock invocation) {
return document(argument.getValue());
}
});
You might want to use verify() in combination with the ArgumentCaptor to assure execution in the test and the ArgumentCaptor to evaluate the arguments:
ArgumentCaptor<Document> argument = ArgumentCaptor.forClass(Document.class);
verify(reader).document(argument.capture());
assertEquals(*expected value here*, argument.getValue());
The argument's value is obviously accessible via the argument.getValue() for further manipulation / checking or whatever you wish to do.
With Java 8, this could be something like this:
Mockito.when(reader.document(anyInt())).thenAnswer(
(InvocationOnMock invocation) -> document(invocation.getArguments()[0]));
I am assuming that document is a map.