I'm working on a project that requires only the use of regular expression to convert state names (must be case insensitive) to their two letter abbreviations.
I cannot use any sort of development environment or link to any databases or xml or ini files.
Please help!
Since states don't have something regular in them regular expressions is the WRONG tool. I would suggest getting a new project.
However, the only solution (apart from stupid illogical hacks) is to hardcore every state:
s/Alabama/Al/
s/Alaska/Ak/
...
s/Wyoming/Wy/
A list of the states and their abbreviations can be found here.
Related
I have a set of Project Names, a set of keywords and a set of paragraphs.
Now my task is, to check whether keywords match any project names , and keywords match any word in any paragraph.
If any set of paragraphs are matched with a keyword and any project matched with same keyword, then I have to assign these paragraphs to that project.
I have been using String Regex for this. But can this be implemented using Natural Language Processing concepts.
If yes... Please let me know how can it be implemented. It would be very helpful for me.
Thanks in advance.
There's no NLP involved in this as such. No matter what you do, you must have to go through all the projects and all the paragraphs at least once. Yes, you can optimize your process by using hashmaps or dictionaries but at the end of the day, you will be searching and matching strings no matter what.
You can do it using dictionaries as mapping becomes easy with the help of dictionaries and regex will be in action too.
I find the Structural Search and Replace feature in IntelliJ IDEs very powerful.
While browsing through the existing templates and discovering my new super powers I came accross the template called "logging without if".
My spider sense urged me to check out the "without" part as it uses invert condition in Complete Match.
However, I am baffled by the expression used in Complete Match.
Here it is:
if('_a) { 'st*; }
Please help me understand how this expression is used.
UPDATE 2017/01/19:
As pointed out by #Faibbus, the docs say that _a and _st are variables.
My confusion is with the variable names.
The names _a and _st only appear here, and nowhere else in the template.
What makes them variables? All other variables in Structural Search are surrounded by $dollar$ signs.
What is the role of the underscores as variable prefix?, what does the apostrophe do in that expression?
I don't find it clear at all. What am I missing?
The expression is using an internal search criteria language. With this language it is possible to specify a complete search query in text without needing all the text fields and checkboxes of the usual Structural Search dialog. This language maybe shouldn't have been exposed and will be more hidden in IntelliJ IDEA 2017.2.
That said, here's a short explanation of the features of the language used:
- a single tick mark indicates a variable. So there are two variables, _a and st.
- a variable not starting with an underscore indicates this variable is target of the search. There can be only one target per query. So st is the target.
- the * indicates zero or more times.
- the rest of the query is a regular Java fragment
For other features of this search criteria language you can check out the source if you are interested.
I have an OWL class Verse wich has a data property named hasContent. Property's range is string. Using DL query, e.g. Verse and hasContent "complete text of a verse", I can find the verse that contains the specified text. I now want to find all intances of verses that contain some word.
Can regular expressions be used in Protege OWL query? Is there any example? Or I need to use the more complicated query language, SPARQL?
You can use XSD facets directly within the OWL Manchester syntax (the syntax what you use in Protege). With a facet you can achieve some of the things you can do with a regex, via the pattern construct. The implementation is reasoner-specific, some it might work sometimes and sometimes not :-/
s an
Some links to learn more about it:
The answers to restrict xsd:string to [A-Z] for rdfs:range contain examples of facet use.
Facets specs.
Or SPARQL as suggested by other answers.
SPARQL is the query language for RDF and there is a reason for it. If you use plain regex (withou SPARQL) you would not be able to define your target (instances, classes, properties etc) and you would not exploit the benefits of using an ontology. Regular expressions are fine for plain texts, but an ontology is not a plain text and you shouldn't handle it as such. I would strongly suggest using SPARQL, which already has included regular expressions when it comes to restricting string values.
Another solution, (I would not by anyway suggest it) is to export your target ontology as an RDF/XML document and apply regular expressions search on it as if it was a simple document.
Hope I helped!
I need to enhance the search functionality on a page listing user accounts. Rather than have multiple search boxes for each possible field, or a drop down menu where the user can only search against one field, I'd like a single search box and to use a gmail like syntax. That's the best way I can describe it, and what I mean by a gmail like search syntax is being able to type the following into the input box:
username:bbaggins type:admin "made up plc"
When the form is submitted, the search string should be split into it's separate parts, which will allow me to construct a SQL query. So for example, type:admin would form part of the WHERE clause so that it would find any record where the field type is equal to admin and the same for username. The text in quotes may be a free text search, but I'm not sure on that yet.
I'm thinking that a regular expression or two would be the best way to do this, but that's something I'm really not good at. Can anyone help to construct a regular expression which could be used for this purpose? I've searched around for some pointers but either I don't know what to search for or it's not out there as I couldn't find anything obvious. Maybe if I understood regular expressions better it would be easier :-)
Cheers,
Adam
No, you would not use regular expressions for this. Just split the string on spaces in whatever language you're using.
You don't necessarily have to use a regex. Regexes are powerful, but in many cases also slow. Regex also does not handle nested parameters very well. It would be easier for you to write a script that uses string manipulation to split the string and extract the keywords and the field names.
If you want to experiment with Regex, try the online REGex tester. Find a tutorial and play around, it's fun, and you should quickly be able to produce useful regexes that find any words before or after a : character, or any sentences between " quotation marks.
thanks for the answers...I did start doing it without regex and just wondered if a regex would be simpler. Sounds like it wouldn't though, so I'll go back to the way I was doing it and test it again.
Good old Mr Bilbo is my go to guy for any naming needs :-)
Cheers,
Adam
What are the common ways to verify the given regex pattern works well of the given scenario and check the results ?
I would like to know in general , not in the particular programming language and what is the best way to learn about writing regular expression ?
Books: Mastering Regular Expressions is the definitive guide to regular expressions. The Regular Expressions Cookbook is said to be lighter and more easily applicable.
Sites: Friedel's companion site is a good start. Regexlib is a source of idioms and patterns.
Software: RegexBuddy is a good, per pay, regex verifier.
I've used this resource when learning: http://www.regular-expressions.info/ and found myself going back there whenever there was something I needed to remember. It's very useful for learning and covers the basics very well. They also have various links to programs which can be used to verify regular expressions.
This is not a "real" verification, but RegexBuddy allows you to verify that your regex does what you expect it to do on any sample data you provide. It also translates the regex into an English description that can help to figure out mistakes. Plus, it knows all major regex flavors and can translate regexes between them.
For testing regular expression you can use RegEx Test tools like one below :
http://www.regextester.com/
To know more about how to learn regular expressions please check following SO threads :
Learning Regular Expressions
How to master Regular Expressions?
https://stackoverflow.com/questions/465119/how-do-i-learn-regular-expressions-closed
RAD Rexexp designer is a great tool
Set up an automated test using your tools of choice (because regex implementations vary from language to language and library to library) which applies the regex to a variety of both matching and non-matching inputs to verify that you get the correct results.
While RegexBuddy and the like may be helpful for initially creating the regex (or may not; I've never used them), you will still need to maintain it, just like any other code. When that time comes, it's vastly preferable to have a test script that will run through all your old test inputs (plus the new ones which created the need for the change) in a matter of seconds rather than having to sit on a website for tens of minutes, if not hours, trying to remember all your test inputs and manually re-run them to make sure you didn't break anything.