Regex -- Turku Agile Day 011

© blog.staffannoteberg.com (1)Regex Habits

Abstract Machine


Glob


Origin


Functions


Architecture


Directed Graph (nondeterministic)


Alphabet


States


Transition Table


Nondeterministic Finite Automata (NFA)


Directed Graph (DFA/NFA)


Deterministic Finite Automata (DFA)


Regular Expressions


Matching One Character


Operator #1: Concatenation


Operator #2: Kleene Star


Operator #3: Alternation


Parentheses


Quiz #2

saippuakivikauppias


Finite


Regular Regex?


Greedy (Kleene Star)


Backtracking (NFA)


Leftmost (NFA Alternation)


Dialects


Regex Literal


Architecture


Regex Objects


Match Object


Quantifiers


Quiz #3

(0|1|2)(0|1|2|3|4|5|6|7|8|9){2}


Quantifier algebra


Positive Closure over Closure


Character Class


Quiz #4

[a-z0-9._-]+@[a-z0-9.-]+\.[a-z]{2,6}


Quiz #5

25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9]


Metacharacters – shorthands


Quiz #6

2(0|1)\d\d1


Quiz #7

(0|(00|\+)358)(4\d|50)\d{7}


Metacharacters – dot


Economical use of Dot


Quiz #8

.+@.+


Metacharacters – Unicode


Quiz #9

\d+(,\d\d)?\s?\u20AC


Assertions – Anchor


Quiz #10

^\s+

\s+$


Assertions – Lookaround


Quiz #11

^(?=.*\d)(?=.*([a-zA-Z])).{8,40}$


Mode


Capture and Backreference


Quiz #12

<(\w+)[^>]*>[^<]*</\1>


Lazy Quantifiers


Web Test bench


REPL Test bench


Test-driven development


Study data source


Accept some incorrect


Deny some correct


Simple method


Shrink or Expand


Split


Blend imperative and regex


Context unaware


Consider Regex modes


Regex Inject Attack


Documentation


Use Lazy Quantifiers


Fail fast


Compile only once


Minimize Nested Quantifiers


Boundaries in find


Applications


Resources


Staffan Nöteberg

Book:Pomodoro Technique Illustratedwww.pomodoro-book.com

Twitter: staffannoteberghttp://blog.staffannoteberg.com

Regex -- Turku Agile Day 011

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