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• Summary
• Use atomic group to avoid backtracking and fail fast
• Extract common repeating substrings out of alternation
• Make use of possessive quantifiers to avoid backtracking
• Use lazy quantifiers strategically instead of greedy quantifiers that cause excessive backtracking
• Avoid unnecessary grouping

• Summary 更新時間：2021-07-02 18:58:53
• Use atomic group to avoid backtracking and fail fast
• Extract common repeating substrings out of alternation
• Make use of possessive quantifiers to avoid backtracking
• Use lazy quantifiers strategically instead of greedy quantifiers that cause excessive backtracking
• Avoid unnecessary grouping
• Use a negated character class instead of the greedy and slow .* or .+
• Use a compiled form of regular expressions
• Optimization and performance enhancement tips
• How to avoid catastrophic backtracking
• Catastrophic or exponential backtracking
• How to test and benchmark your regular expression performance
• Do not use regular expressions to parse XML / HTML data
• The mistake of calling matcher.goup() without a prior call to matcher.find() matcher.matches() or matcher.lookingAt()
• Do not use an unescaped hyphen in the middle of a character class
• Use the limiting quantifier instead of repeating a character or pattern multiple times
• Use predefined character classes instead of longer versions
• However don't forget to use the required group around alternation
• Avoid unnecessary capturing groups to reduce memory consumption
• Avoid escaping every non-word character
• Do not forget to escape regex metacharacters outside a character class
• Common pitfalls and ways to avoid them while writing regular expressions
• Regular Expression Pitfalls Optimization and Performance Improvements
• Summary
• Why should you use composite character classes?
• The subtraction of character classes
• The intersection of character classes
• The union of character classes
• Understanding the Union Intersection and Subtraction of Character Classes
• Summary
• Lookbehind limitations in Java regular expressions
• Be careful with capturing groups inside a lookahead or lookbehind atomic group
• Capturing text from overlapping matches
• Negative lookbehind
• Positive lookbehind
• Lookbehind assertions
• Negative lookahead
• Positive lookahead
• Lookahead assertions
• Atomic groups
• \G boundary assertion
• Regex defined zero-width assertions
• Predefined zero-width assertions
• Zero-width assertions
• Exploring Zero-Width Assertions Lookarounds and Atomic Groups
• Summary
• Example of the appendReplacement and appendTail methods
• The appendTail(StringBuffer sb) method
• The appendReplacement(StringBuffer sb String replacement) method
• The find() and find(int start) methods
• The matches() method
• Method Boolean lookingAt()
• Examples using the Matcher class
• The Matcher class
• Filtering a list of tokens using the asPredicate() method
• Examples using the Pattern class
• The Pattern class
• The MatchResult interface
• Introduction to Java Regular Expression APIs - Pattern and Matcher Classes
• Summary
• Using regular expressions in Java Scanner API
• Example of the split method using the limit parameter
• Examples of the split method
• The limit parameter rules
• Methods - String split methods
• Examples of the replaceFirst method
• Method - String replaceFirst(String regex String replacement)
• Examples of the replaceAll method
• Method - String replaceAll(String regex String replacement)
• Example of the matches method
• Method - boolean matches(String regex)
• Introduction to the Java String API for regular expressions' evaluation
• Regular Expression Programming Using Java String and Scanner APIs
• Summary
• Invalid (non-existing) backward or forward references
• Forward references
• Replacement reference of a named group
• Back reference of a named group
• Back references
• Advantages of non-capturing groups
• Non-capturing groups
• Named groups
• Group numbering
• Capturing groups
• Working with Groups Capturing and References
• Summary
• Disabling mode modifiers
• The placement of embedded modes in a Java regular expression
• Embedded regular expression mode modifiers
• Double escaping in a Java String when defining regular expressions
• Examples of matching Unicode text in regular expressions
• Unicode scripts support
• Negation of the preceding regex directives
• Commonly used Unicode character properties
• Unicode support in Java regular expressions
• POSIX character classes
• Predefined shorthand character classes
• Examples of negated character classes
• Negated character classes
• Literally matching a string that may contain special regex metacharacters
• Examples of escaping rules inside the character class
• Escaping inside a character class
• Escaping special regex metacharacters and escaping rules inside the character classes
• Examples of character range
• Range inside a character class
• Examples of character classes
• Character classes
• Examples using boundary constructs
• Boundary constructs
• Possessive quantifiers
• Greedy versus reluctant (lazy) matching using quantifiers
• Examples using quantifiers
• Basic quantifiers
• Quantifiers
• Understanding the core constructs of regular expressions
• Understanding the Core Constructs of Java Regular Expressions
• Summary
• The effect of eager matching on regular expression alternation
• Eager matching
• Some basic regular expression examples
• Constructs of the standard regular expression and meta characters
• The basic rules of regular expressions
• What type of problems need regular expressions to solve
• Various flavors of regular expressions
• A bit of history of regular expressions
• Introduction to regular expressions
• Getting Started with Regular Expressions
• Questions
• Piracy
• Errata
• Downloading the example code
• Customer support
• Reader feedback
• Conventions
• Who this book is for
• What you need for this book
• What this book covers
• Preface
• Customer Feedback
• Why subscribe?
• www.PacktPub.com
• About the Reviewer
• About the Author
• Credits
• Title page
• coverpage

• coverpage
• Title page
• Credits
• About the Author
• About the Reviewer
• www.PacktPub.com
• Why subscribe?
• Customer Feedback
• Preface
• What this book covers
• What you need for this book
• Who this book is for
• Conventions
• Reader feedback
• Customer support
• Downloading the example code
• Errata
• Piracy
• Questions
• Getting Started with Regular Expressions
• Introduction to regular expressions
• A bit of history of regular expressions
• Various flavors of regular expressions
• What type of problems need regular expressions to solve
• The basic rules of regular expressions
• Constructs of the standard regular expression and meta characters
• Some basic regular expression examples
• Eager matching
• The effect of eager matching on regular expression alternation
• Summary
• Understanding the Core Constructs of Java Regular Expressions
• Understanding the core constructs of regular expressions
• Quantifiers
• Basic quantifiers
• Examples using quantifiers
• Greedy versus reluctant (lazy) matching using quantifiers
• Possessive quantifiers
• Boundary constructs
• Examples using boundary constructs
• Character classes
• Examples of character classes
• Range inside a character class
• Examples of character range
• Escaping special regex metacharacters and escaping rules inside the character classes
• Escaping inside a character class
• Examples of escaping rules inside the character class
• Literally matching a string that may contain special regex metacharacters
• Negated character classes
• Examples of negated character classes
• Predefined shorthand character classes
• POSIX character classes
• Unicode support in Java regular expressions
• Commonly used Unicode character properties
• Negation of the preceding regex directives
• Unicode scripts support
• Examples of matching Unicode text in regular expressions
• Double escaping in a Java String when defining regular expressions
• Embedded regular expression mode modifiers
• The placement of embedded modes in a Java regular expression
• Disabling mode modifiers
• Summary
• Working with Groups Capturing and References
• Capturing groups
• Group numbering
• Named groups
• Non-capturing groups
• Advantages of non-capturing groups
• Back references
• Back reference of a named group
• Replacement reference of a named group
• Forward references
• Invalid (non-existing) backward or forward references
• Summary
• Regular Expression Programming Using Java String and Scanner APIs
• Introduction to the Java String API for regular expressions' evaluation
• Method - boolean matches(String regex)
• Example of the matches method
• Method - String replaceAll(String regex String replacement)
• Examples of the replaceAll method
• Method - String replaceFirst(String regex String replacement)
• Examples of the replaceFirst method
• Methods - String split methods
• The limit parameter rules
• Examples of the split method
• Example of the split method using the limit parameter
• Using regular expressions in Java Scanner API
• Summary
• Introduction to Java Regular Expression APIs - Pattern and Matcher Classes
• The MatchResult interface
• The Pattern class
• Examples using the Pattern class
• Filtering a list of tokens using the asPredicate() method
• The Matcher class
• Examples using the Matcher class
• Method Boolean lookingAt()
• The matches() method
• The find() and find(int start) methods
• The appendReplacement(StringBuffer sb String replacement) method
• The appendTail(StringBuffer sb) method
• Example of the appendReplacement and appendTail methods
• Summary
• Exploring Zero-Width Assertions Lookarounds and Atomic Groups
• Zero-width assertions
• Predefined zero-width assertions
• Regex defined zero-width assertions
• \G boundary assertion
• Atomic groups
• Lookahead assertions
• Positive lookahead
• Negative lookahead
• Lookbehind assertions
• Positive lookbehind
• Negative lookbehind
• Capturing text from overlapping matches
• Be careful with capturing groups inside a lookahead or lookbehind atomic group
• Lookbehind limitations in Java regular expressions
• Summary
• Understanding the Union Intersection and Subtraction of Character Classes
• The union of character classes
• The intersection of character classes
• The subtraction of character classes
• Why should you use composite character classes?
• Summary
• Regular Expression Pitfalls Optimization and Performance Improvements
• Common pitfalls and ways to avoid them while writing regular expressions
• Do not forget to escape regex metacharacters outside a character class
• Avoid escaping every non-word character
• Avoid unnecessary capturing groups to reduce memory consumption
• However don't forget to use the required group around alternation
• Use predefined character classes instead of longer versions
• Use the limiting quantifier instead of repeating a character or pattern multiple times
• Do not use an unescaped hyphen in the middle of a character class
• The mistake of calling matcher.goup() without a prior call to matcher.find() matcher.matches() or matcher.lookingAt()
• Do not use regular expressions to parse XML / HTML data
• How to test and benchmark your regular expression performance
• Catastrophic or exponential backtracking
• How to avoid catastrophic backtracking
• Optimization and performance enhancement tips
• Use a compiled form of regular expressions
• Use a negated character class instead of the greedy and slow .* or .+
• Avoid unnecessary grouping
• Use lazy quantifiers strategically instead of greedy quantifiers that cause excessive backtracking
• Make use of possessive quantifiers to avoid backtracking
• Extract common repeating substrings out of alternation
• Use atomic group to avoid backtracking and fail fast
• Summary 更新時間：2021-07-02 18:58:53