word-boundary | 易学教程

How to achieve word boundary in Sqlite Android?

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问题 I would like to achieve the following (a full text search), SELECT * FROM tablename where columnname REGEXP '[[:<:]]some string[[:>:]]' Where i am interested in only exact strings (not just words) from a full text column. I have been using the exact SQL above in MySQL and now migrating most of the code to android apps. But I have been looking at various posts where it is mentioned that REGEXP isn't supported in Android Sqlite (for example: link1, link2, link3 ). Is there a way to enable

What's the difference between \b and \>, \< in regex?

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问题 Now, I'm quite confused. I was found this in regex cheat sheet \b word boundary \< start of word \> end of word But in "Mastering Regular Expression" book, it told me that \< word boundary \> word boundary What's the difference between \b and \> \< in regex? 回答1: Summary \b word boundary \< word boundary; specifically, word boundary followed by a word; ie, start of word \> word boundary; specifically, word followed by word boundary; ie, end of word If you have a word like "bob" then the \b

Regex word boundary alternative

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问题 I was using the standard \b word boundary. However, it doesn't quite deal with the dot (.) character the way I want it to. So the following regex: \b(\w+)\b will match cats and dogs in cats.dog if I have a string that says cats and dogs don't make cats.dogs . I need a word boundary alternative that will match a whole word only if: it does not contain the dot(.) character it is encapsulated by at least one space( ) character on each side Any ideas?! P.S. I need this for PHP 回答1: You could try

What's the difference between \\b and \\>, \\< in regex?

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Now, I'm quite confused. I was found this in regex cheat sheet \b word boundary \< start of word \> end of word But in "Mastering Regular Expression" book, it told me that \< word boundary \> word boundary What's the difference between \b and \> \< in regex? Summary \b word boundary \< word boundary; specifically, word boundary followed by a word; ie, start of word \> word boundary; specifically, word followed by word boundary; ie, end of word If you have a word like "bob" then the \b word boundary pattern will return two zero length matches that are equivalent to the start and the end of the

Are there JavaScript equivalents of the Vim regular expression start and end of word atoms “\<” and “\>”?

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问题 I know most regular expression engines, including the one in JavaScript have \b to match a word boundary, be it at either the start or end of a word. But Vim also has two more specific regular expression atoms: \< matches only the word boundary at the start of a word \> matches only the word boundary at the end of a word Does JavaScript have an equivalent to these atoms, and if not is there a way to express their more precise semantics some other way? 回答1: As far as I know there is nothing

How to find a word within text using XSLT 2.0 and REGEX (which doesn't have \b word boundary)?

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问题 I am attempting to scan a string of words and look for the presence of a particular word(case insensitive) in an XSLT 2.0 stylesheet using REGEX. I have a list of words that I wish to iterate over and determine whether or not they exist within a given string. I want to match on a word anywhere within the given text, but I do not want to match within a word (i.e. A search for foo should not match on " foo d" and a search for bar should not match on "re bar "). XSLT 2.0 REGEX does not have a

Regular expression to match boundary between different Unicode scripts

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问题 Regular expression engines have a concept of "zero width" matches, some of which are useful for finding edges of words: \b - present in most engines to match any boundary between word and non-word characters \< and \> - present in Vim to match only the boundary at the beginning of a word, and at the end of a word, respectively. A newer concept in some regular expression engines is Unicode classes. One such class is script, which can distinguish Latin, Greek, Cyrillic, etc. These examples are

Python regex words boundary with unexpected results

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问题 import re sstring = "ON Any ON Any" regex1 = re.compile(r''' \bON\bANY\b''', re.VERBOSE) regex2 = re.compile(r'''\b(ON)?\b(Any)?''', re.VERBOSE) regex3 = re.compile(r'''\b(?:ON)?\b(?:Any)?''', re.VERBOSE) for a in regex1.findall(sstring): print(a) print("----------") for a in regex2.findall(sstring): print(a) print("----------") for a in regex3.findall(sstring): print(a) print("----------") ('ON', '') ('', '') ('', 'Any') ('', '') ('ON', '') ('', '') ('', 'Any') ('', '') ON Any ON Any Having

How to not replace when preceded with some characters using String's replaceAll

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问题 I need to replace some words in a text, but I need to put conditions in the replacement strategy as follows: I want to replace word1 with word2 : String word1 = "word1"; String word2 = "word2"; but I don't want to replace word1 if it's preceded by word3 which is: String word3 = "word3."; //with the dot at the ending That is if the text is word3.word1 I don't want to touch it. But I can't seem to handle that with word boundaries using String 's replaceAll method. EDIT: And also I don't want to

Python regex words boundary with unexpected results

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import re sstring = "ON Any ON Any" regex1 = re.compile(r''' \bON\bANY\b''', re.VERBOSE) regex2 = re.compile(r'''\b(ON)?\b(Any)?''', re.VERBOSE) regex3 = re.compile(r'''\b(?:ON)?\b(?:Any)?''', re.VERBOSE) for a in regex1.findall(sstring): print(a) print("----------") for a in regex2.findall(sstring): print(a) print("----------") for a in regex3.findall(sstring): print(a) print("----------") ('ON', '') ('', '') ('', 'Any') ('', '') ('ON', '') ('', '') ('', 'Any') ('', '') ON Any ON Any Having read many articles on the internet and S.O. I think I still don't understand the regex word boundary: