To reduce size of my simulation output files, I want to give variable name exceptions instead of a list of many certain variables to the simulationsOptions/outputFilter (cf. OpenModelica Users Guide / Output) of my model. I found the regexp operator "^" to fullfill my needs, but that didn't work as expected. So I think that something is wrong with the interpretation of connected character strings when negated.
Example:
When I have any derivatives der(...) in my model and use variableFilter=der.* the output file will contain all the filtered derivatives. Since there are no other varibles beginning with character d the same happens with variableFilter=d.*. For testing I also tried variableFilter=rde.* to confirm that every variable is filtered.
When I now try to except by variableFilter=^der.*, =^rde.* or =^d.*, I get exactly the same result as without using ^. So the operator seems to be ignored in this notation.
When I otherwise use variableFilter=[^der].*, =[^rde].* or even =[^d].*, all wanted derivation variables are filtered from the ouput, but there is no difference between those three expressions above. For me it seems that every character is interpretated standalone and not as as a connected string.
Did I understand and use the regexp usage right or could this be a code bug?
Side/follow-up question: Where can I officially report this for software revision?
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OpenModelica v.1.19.2 (64-bit)
I am working with a messy manually maintained "database" that has a column containing a string with name,value pairs. I am trying to parse the entire column with regexp to pull out the values. The column is huge (>100,000 entries). As a proxy for my actual data, let's use this code:
line1={'''thing1'': ''-583'', ''thing2'': ''245'', ''thing3'': ''246'', ''morestuff'':, '''''};
line2={'''thing1'': ''617'', ''thing2'': ''239'', ''morestuff'':, '''''};
line3={'''thing1'': ''unexpected_string(with)parens5'', ''thing2'': 245, ''thing3'':''246'', ''morestuff'':, '''''};
mycell=vertcat(line1,line2,line3);
This captures the general issues encountered in the database. I want to extract what thing1, thing2, and thing3 are in each line using cellfun to output a scalar cell array. They should normally be 3 digit numbers, but sometimes they have an unexpected form. Sometimes thing3 is completely missing, without the name even showing up in the line. Sometimes there are minor formatting inconsistencies, like single quotes missing around the value, spaces missing, or dashes showing up in front of the three digit value. I have managed to handle all of these, except for the case where thing3 is completely missing.
My general approach has been to use expressions like this:
expr1='(?<=thing1''):\s?''?-?([\w\d().]*?)''?,';
expr2='(?<=thing2''):\s?''?-?([\w\d().]*?)''?,';
expr3='(?<=thing3''):\s?''?-?([\w\d().]*?)''?,';
This looks behind for thingX' and then tries to match : followed by zero or one spaces, followed by 0 or 1 single quote, followed by zero or one dash, followed by any combination of letters, numbers, parentheses, or periods (this is defined as the token), using a lazy match, until zero or one single quote is encountered, followed by a comma. I call regexp as regexp(___,'tokens','once') to return the matching token.
The problem is that when there is no match, regexp returns an empty array. This prevents me from using, say,
out=cellfun(#(x) regexp(x,expr3,'tokens','once'),mycell);
unless I call it with 'UniformOutput',false. The problem with that is twofold. First, I need to then manually find the rows where there was no match. For example, I can do this:
emptyout=cellfun(#(x) isempty(x),out);
emptyID=find(emptyout);
backfill=cell(length(emptyID),1);
[backfill{:}]=deal('Unknown');
out(emptyID)=backfill;
In this example, emptyID has a length of 1 so this code is overkill. But I believe this is the correct way to generalize for when it is longer. This code will change every empty cell array in out with the string Unknown. But this leads to the second problem. I've now got a 'messy' cell array of non-scalar values. I cannot, for example, check unique(out) as a result.
Pardon the long-windedness but I wanted to give a clear example of the problem. Now my actual question is in a few parts:
Is there a way to accomplish what I'm trying to do without using 'UniformOutput',false? For example, is there a way to have regexp pass a custom string if there is no match (e.g. pass 'Unknown' if there is no match)? I can think of one 'cheat', which would be to use the | operator in the expression, and if the first token is not matched, look for something that is ALWAYS found. I would then still need to double back through the output and change every instance of that result to 'Unknown'.
If I take the 'UniformOutput',false approach, how can I recover a scalar cell array at the end to easily manipulate it (e.g. pass it through unique)? I will admit I'm not 100% clear on scalar vs nonscalar cell arrays.
If there is some overall different approach that I'm not thinking of, I'm also open to it.
Tangential to the main question, I also tried using a single expression to run regexp using 3 tokens to pull out the values of thing1, thing2, and thing3 in one pass. This seems to require 'UniformOutput',false even when there are no empty results from regexp. I'm not sure how to get a scalar cell array using this approach (e.g. an Nx1 cell array where each cell is a 3x1 cell).
At the end of the day, I want to build a table using these results:
mytable=table(out1,out2,out3);
Edit: Using celldisp sheds some light on the problem:
celldisp(out)
out{1}{1} =
246
out{2} =
Unknown
out{3}{1} =
246
I assume that I need to change the structure of out so that the contents of out{1}{1} and out{3}{1} are instead just out{1} and out{3}. But I'm not sure how to accomplish this if I need 'UniformOutput',false.
Note: I've not used MATLAB and this doesn't answer the "efficient" aspect, but...
How about forcing there to always be a match?
Just thinking about you really wanting a match to skip this problem, how about an empty match?
Looking on the MATLAB help page here I can see a 'emptymatch' option, perhaps this is something to try.
E.g.
the_thing_i_want_to_find|
Match "the_thing_i_want_to_find" or an empty match, note the | character.
In capture group it might look like this:
(the_thing_i_want_to_find|)
As a workaround, I have found that using regexprep can be used to find entries where thing3 is missing. For example:
replace='$1 ''thing3'': ''Unknown'', ''morestuff''';
missingexpr='(?<=thing2'':\s?)(''?-?[\w\d().]*?''?,) ''morestuff''';
regexprep(mycell{2},missingexpr,replace)
ans =
''thing1': '617', 'thing2': '239', 'thing3': 'Unknown', 'morestuff':, '''
Applying it to the entire array:
fixedcell=cellfun(#(x) regexprep(x,missingexpr,replace),mycell);
out=cellfun(#(x) regexp(x,expr3,'tokens','once'),fixedcell,'UniformOutput',false);
This feels a little roundabout, but it works.
cellfun can be replaced with a plain old for loop. Your code will either be equally fast, or maybe even faster. cellfun is implemented with a loop anyway, there is no advantage of using it other than fewer lines of code. In your explicit loop, you can then check the output of regexp, and build your output array any way you like.
I want to create a rule that requires a non-number, non-letter character to be consecutively repeated three times. The rule would look something like this:
# Note, this code does not do what I want!
grammar ThreeCharacters
rule threeConsecutiveCharacters
(![a-zA-Z0-9] .) 3..3
end
end
Is there any way to require the first character that it detects to be repeated three times?
There was previously a similar question about detecting the number of indentations: PEG for Python style indentation
The solution there was to first initialize the indentation stack:
&{|s| #indents = [-1] }
Then save the indentation for the current line:
&{|s|
level = s[0].indentation.text_value.length
#indents << level
true
}
Whenever a new line begins it peeks at the indentation like this:
!{|s|
# Peek at the following indentation:
save = index; i = _nt_indentation; index = save
# We're closing if the indentation is less or the same as our enclosing block's:
closing = i.text_value.length <= #indents.last
}
If the indentation is larger it adds the new indentation level to the stack.
I could create something similar for my problem, but this seems like a very tedious way to solve it.
Are there any other ways to create my rule?
Yes, you can do it this way in Treetop. This kind of thing not generally possible with a PEG because of the way packrat parsing works; it's greedy but you need to limit its greed using semantic information from earlier in the parse. It's only the addition in Treetop of semantic predicates (&{...}} that make it possible. So yes, it's tedious. You might consider using Rattler instead, as it has a significant number of features in addition to those available in Treetop. I can't advise (as maintainer of Treetop, but not being a user of Rattler) but I am very impressed by its feature set and I think it will handle this case better.
If you proceed with Treetop, bear in mind that every semantic predicate should return a boolean value indicating success or failure. This is not explicit in the initialisation of #indents above.
I have an outgoing web service to send data from Siebel 7.8 to an external system. In order for the integration to work, before I send the data, I must change one of the field values, replacing every occurence of "old" with "new". How can I do this with EAI data mappings?
In an ideal world I would just use an integration source expression like Replace([Description], "old", "new"). However Siebel is far from ideal, and doesn't have a replace function (or if it does, it's not documented). I can use all the Siebel query language functions which don't need an execution context. I can also use the functions available for calculated fields (sane people could expect both lists to be the same, but Siebel documentation is also far from ideal).
My first attempt was to use the InvokeServiceMethod function and replace the text myself in eScript. So, this is my field map source expression:
InvokeServiceMethod('MyBS', 'MyReplace', 'In="' + [Description] + '"', 'Out')
After some configuration steps it works fine... except if my description field contains the " character: Error parsing expression 'In="This is a "test" with quotes"' for field '3' (SBL-DAT-00481)
I know why this happens. My double quotes are breaking the expression and I have to escape them by doubling the character, as in This is a ""test"" with quotes. However, how can I replace each " with "" in order to call my business service... if I don't have a replace function? :)
Oracle's support web has only one result for the SBL-DAT-00481 error, which as a workaround, suggests to place the whole parameter inside double quotes (which I already had). There's a linked document in which they acknowledge that the workaround is valid for a few characters such as commas or single quotes, but due to a bug in Siebel 7.7-7.8 (not present in 8.0+), it doesn't work with double quotes. They suggest to pass instead the row id as argument to the business service, and then retrieve the data directly from the BC.
Before I do that and end up with a performance-affecting workaround (pass only the ID) for the workaround (use double quotes) for the workaround (use InvokeServiceMethod) for not having a replace function... Am I going crazy here? Isn't there a simple way to do a simple text replacement in a Siebel data mapping?
first thing (quite possibly - far from optimal one) which is coming to my mind - is to create at source BC calculated field, aka (NEW_VALUE), which becomes "NEW" for every record, where origin field has a value "OLD". and simply use this field in integration map.
I am writing an API for my app, and I am confused about how Jax-RS deals with certain scenarios
For example, I define two paths:
#Path("user/{name : [a-zA-Z]+}")
and
#Path("user/me")
The first path that I specified clearly encompasses the second path since the regular expression includes all letters a-z. However, the program doesn't seem to have an issue with this. Is it because it defaults to the most specific path (i.e. /me and then looks for the regular expression)?
Furthermore, what happens if I define two regular expressions as the path with some overlap. Is there a default method which will be called?
Say I want to create three paths for three different methods:
#Path{"user/{name : [a-zA-Z]+}")
#Path("user/{id : \\d+}")
#Path("user/me")
Is this best practice/appropriate? How will it know which method to call?
Thank you in advance for any clarification.
This is in the spec in "Matching Requests to Resource Methods"
Sort E using (1) the number of literal characters in each member as the primary key (descending order), (2) the number of capturing groups as a secondary key (descending order), (3) the number of capturing groups with non-default regular expressions (i.e. not ‘([^ /]+?)’) as the tertiary key (descending order), ...
What happens is the candidate methods are sorted by specified ordered "key". I highlight them in bold.
The first sort key is the number of literal characters. So for these three
#Path{"user/{name : [a-zA-Z]+}")
#Path("user/{id : \\d+}")
#Path("user/me")
if the requested URI is ../user/me, the last one will always be chosen, as it has the most literal characters (7, / counts). The others only have 5.
Aside from ../users/me anything else ../users/.. will depend on the regex. In your case one matches only numbers and one matches only letters. There is no way for these two regexes to overlap. So it will match accordingly.
Now just for fun, let's say we have
#Path{"user/{name : .*}")
#Path("user/{id : \\d+}")
#Path("user/me")
If you look at the top two, we now have overlapping regexes. The first will match all numbers, as will the second one. So which one will be used? We can't make any assumptions. This is a level of ambiguity not specified and I've seen different behavior from different implementations. AFAIK, there is no concept of a "best matching" regex. Either it matches or it doesn't.
But what if we wanted the {id : \\d+} to always be checked first. If it matches numbers then that should be selected. We can hack it based on the specification. The spec talks about "capturing groups" which are basically the {..}s. The second sorting key is the number of capturing groups. The way we could hack it is to add another "optional" group
#Path{"user/{name : .*}")
#Path("user/{id : \\d+}{dummy: (/)?}")
Now the latter has more capturing groups so it will always be ahead in the sort. All it does is allow an optional /, which doesn't really affect the API, but insures that if the request URI is all numbers, this path will always be chose.
You can see a discussion with some test cases in this answer