asp.net mvc - Tokenizing a expression string in C# -

-

i have calculation formula string of form

 string formula = w_tb + min(d_3,a_x) * pow(x,2)

in above example w_tb, d_3, a_x, x variables. able find list of variables in formula splitting strings using operands delimiter.

but in order assign values variables (value database), first approach replace variable name value of variable database. result in replacing substring of expression string value. eg : if variable x replaced value 1,2 in expression string a_x replaced a_1,2 not required result.

i have list of variables , and complete list of delimiters(operators).

what trying achieve?

i trying following list expression string

list<string>() {"w_tb","+","min","(","d_3",",","a_x",")","*","pow","(","x",",","2",")"}

is there way achieve task.

i have tried solution mentioned in this answer. tokenizer having string.

what trying called parsing, used compilers.

you can define simple grammar expression , let parser-generator generate parser code you. allows define syntax errors , gives full token list 1 want. example in antlr. have http://www.antlr.org/


Comments

Post a Comment

Popular posts from this blog

android - Why am I getting the message 'Youractivity.java is not an activity subclass or alias' -

-
Image
i created own android project , cut , pasted code exercise: http://androidexample.com/show_phone_contacts_in_autocomplete_suggestions_-_android_example%20/index.php?view=article_discription&aid=106&aaid=128# when build project no errors or warnings. when run project window error: annoyingly, can't make window smaller, can't click of buttons. cick 'x' @ top, close it. here's project structure: where getting 'autocompletemain' from? (note small c) class named autocompletemain. help. and have activity included in android manifest, in case you're wondering: <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.androidexample.autocompleteedittext" android:versioncode="1" android:versionname="1.0" > <uses-permission android:name="android.permission.read_phone_state...
Read more

python - How do I create a list index that loops through integers in another list -

-
i have list: sentences = ['the number of adults read @ least 1 novel within past 12 months fell 47%.', 'fiction reading rose 2002 2008.', 'the decline in fiction reading last year occurred among men.', 'women read more fiction.', '50% more.', 'though decreased 10% on last decade.', 'men more read nonfiction.', 'young adults more read fiction.', 'just 54% of americans cracked open book of kind last year.', 'but novels have suffered more nonfiction.'] and have list containing indexes of sequences of sentences in above list contain number. index_groupings = [[0, 1], [4, 5], [8]] i want extract specified sentence sequences in variable "sentences" using indexes in variable "index_groupings" following output: the number of adults read @ least 1 novel within past 12 months fell 47%.fiction reading rose 2002 2008. 50% more.though decreased 10% on last decade. just 54% of a...
Read more

c# - “System.Security.Cryptography.CryptographicException: Keyset does not exist” when reading private key from remote machine -

-
i trying decrypt data using certificate private key. works fine when certificate installed on local machine (i using self signed certificate testing , have private key certificate) when try access private key remote machine using same code, "keyset not exist" exception. i using console application testing, , have made sure id have read permissions on private key on remote server. here sample code using: var store = new x509store(@"\\server1\my", storelocation.localmachine); store.open(openflags.readonly); var result = store.certificates.find(x509findtype.findbysubjectname, "server1.test.com", false); var certificate = result[0]; store.close(); //this succeeds both local , remote server var rsapublic = (rsacryptoserviceprovider)certificate.publickey.key; //this succeeds local, fails remote server var rsaprivate = (rsacryptoserviceprovider)certificate.privatekey; here exception call stack unhandled exception: system.security.cryptography.crypto...
Read more