reg ex
TRANSCRIPT
TEXT PARSING THE EASY WAY
Regular Expressions
March 7-8, 2015
Copyright © Jeff Hart, 2015
1
J e f f H a r t
V a n i s h i n g C l o u d s , I n c .
Levels of Pain
Regular expressions by copying
Leveraging (special) metachars
Advanced topics
Environment
Substitutions
Automating testing
Syntax influences
Novice
Apprentice
Journeyman
Master
Copyright © Jeff Hart, 2015
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Why?
Language for parsing text
Spawned Perl
Native type in JavaScript
First class (class) in .Net
Largely independent of host environment
Line breaks, case sensitivity, etc.
Replace a ton of .indexOf(), .substring(), .contains() …
var regex = /hello/ig
var regex = new System.Text.RegularExpressions.RegEx(@"hello");
Copyright © Jeff Hart, 2015
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RegEx on a Page
^ $
?*+ {}
\
()
|
[<{
.
(anchors) From the beginning to the end
(cardinality) …count on
(backslash) …escaping
(both) …parenthesis
(pipe) …or
(starting) …opening brackets
(period) …and anything in between
Copyright © Jeff Hart, 2015
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Scanning Method
Search: "The levels of confusion: SNAFU, SUSFU, TARFU and FUBAR"
FU
FU FU FU FU
RegEx:
Copyright © Jeff Hart, 2015
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RegEx
Brief, terse, powerful
Getting to a “journeyman” level takes only a few hours
Use a REPL tool like PowerShell or sites like:
http://regexpal.com/
http://regexhero.net/tester/
When the only tool you know…
^$ . *+? \ () | <{[
Copyright © Jeff Hart, 2015
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SpeakerRate.com
• Search for “regex” or “socalcodecamp”• h t t p : / / s p e a k e r r a t e . c o m / t a l k s / 4 9 3 1 1 - s o c a l c o d e c a m p - i n t r o - t o - r e g e x
Thank YOU!
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