Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Regular expressions basics/正規表現の基本
Search
Kishikawa Katsumi
July 26, 2022
Programming
7
680
Regular expressions basics/正規表現の基本
Regular expressions basics/正規表現の基本
Kishikawa Katsumi
July 26, 2022
Tweet
Share
More Decks by Kishikawa Katsumi
See All by Kishikawa Katsumi
Enhancing Applications with Accessibility API
kishikawakatsumi
3
2.6k
Mastering SwiftSyntax
kishikawakatsumi
3
4.7k
My SwiftData Review
kishikawakatsumi
7
1.3k
Swift Expression Macros: a practical introduction
kishikawakatsumi
3
1.7k
Xcode Cloudの評価
kishikawakatsumi
2
1.2k
家のいろいろな数値を計測する
kishikawakatsumi
4
2k
GitHub Actionsでテストの結果をわかりやすく表示する
kishikawakatsumi
1
860
GitHub Actionsでテストの結果をわかりやすく表示する
kishikawakatsumi
1
1.7k
Network ExtensionでiOSデバイス上で動くパケットキャプチャを作る
kishikawakatsumi
7
7.2k
Other Decks in Programming
See All in Programming
大規模マルチテナントを解決するYugabyteDBという選択肢
nnaka2992
1
250
最近追加した型の紹介とその振り返り
aki19035vc
0
170
しくじり先生 Image Matching Challenge 2024 編
goosehaaan
0
810
Folding Cheat Sheet #7
philipschwarz
PRO
0
150
Modern Angular: Renovation for Your Applications
manfredsteyer
PRO
0
140
CSC307 Lecture 11
javiergs
PRO
0
240
HMSコンペ 11th Solution (team : kansai-kaggler)
t88
1
680
Findy - エンジニア向け会社紹介 / Findy Letter for Engineers
findyinc
2
81k
CSC307 Lecture 06
javiergs
PRO
0
360
みんなのオブザーバビリティプラットフォームを作ってるんだがパフォーマンスがやばい #mackerelio #srenext
ne_sachirou
0
370
CSC307 Lecture 12
javiergs
PRO
0
220
ぼっちを避けて楽しむためのアノテコノテ / Various Tips and Tricks to Avoid Loneliness and Have Fun
nrslib
3
1.7k
Featured
See All Featured
The Cult of Friendly URLs
andyhume
75
5.9k
Making Projects Easy
brettharned
111
5.7k
Adopting Sorbet at Scale
ufuk
71
8.8k
Bootstrapping a Software Product
garrettdimon
PRO
304
110k
Code Review Best Practice
trishagee
58
16k
The Art of Programming - Codeland 2020
erikaheidi
48
13k
Git: the NoSQL Database
bkeepers
PRO
423
64k
It's Worth the Effort
3n
181
27k
Unsuck your backbone
ammeep
666
57k
Building Your Own Lightsaber
phodgson
101
5.9k
Creatively Recalculating Your Daily Design Routine
revolveconf
214
11k
The Cost Of JavaScript in 2023
addyosmani
31
4.7k
Transcript
ਖ਼نදݱͷجຊ Regular expressions basics
Swift Regex
https://swiftregex.com/
ਖ਼نදݱͱ • จࣈྻͷू߹ʢύλʔϯʣΛද͢൚༻తͳه๏ • [bc]ookbook·ͨcookʹϚον͢Δ
Ϧςϥϧ Literal Characters • a • Jack is a boy,
• cat • About cats and dogs
ϝλจࣈ Special Characters (Meta Characters) • ಛผͳҙຯΛ࣋ͭ12ͷจࣈʢϦςϥϧͱͯ͠ѻ͏ʹΤεέʔϓ͕ඞཁɻʢྫʣ1\+1=2ʣ • όοΫεϥογϡ \
• ΩϟϨοτ ^ • υϧϚʔΫ $ • υοτʢϐϦΦυʣ . • ύΠϓ | • ΫΤενϣϯϚʔΫ ? • ΞελϦεΫ * • ϓϥε + • ։ؙ͖Χοί ( • ดؙ͡Χοί ) • ։͖֯Χοί [ • ։͖Χοί {
੍ޚจࣈ Non-Printable Characters (Control Characters, Escape sequence) • \t •
λϒʹϚον͢Δ • \n • վߦʹϚον͢Δ
จࣈΫϥε Character Classes (Character Sets) • ෳͷจࣈͷத͔Β̍ͭͷจࣈʹϚον͢Δ • a·ͨeʹϚονͤ͞Δʹ[ae]ͱॻ͘ •
ʢྫʣgr[ae]y • gray·ͨgreyʹϚον • จࣈΫϥε1ͭͷจࣈʹϚον͢Δ • Χοίͷதͷจࣈͷॱংؔͳ͍
จࣈΫϥε Character Classes (Character Sets) • จࣈΫϥεͷதͰϋΠϑϯΛ༻ͯ͠ൣғΛࢦఆͰ͖Δ • [0-9] •
͔̌Β̕ͷؒͷܻ̍ͷࣈʹϚον • [0-9a-fA-F] • େจࣈͱখจࣈΛ۠ผͤͣʹɺ16ਐͷࣈܻ̍ʹϚον • ൱ఆจࣈΫϥεʢNegated Character Classesʣ • [^0-9\r\n] • ࣈ·ͨվߦͰͳ͍ҙͷจࣈʹϚον
จࣈΫϥεʢͷུه๏ʣ Shorthand Character Classes • จࣈΫϥεͷதͰΑ͘ΘΕΔͷΛ؆୯ʹॻ͚ΔΑ͏ʹ͋Β͔͡Ί༻ҙ͞Εͨه๏ • \d[0-9]ͷུه๏ • UnicodeΛαϙʔτ͢ΔڥͰࣈؙࣈͳͲͯ͢ͷࣈʹϚον
• \w “word character” [A-Za-z0-9_]ͱಉ͡ʢΞϯμʔείΞؚ͕·ΕΔ͜ͱʹҙʣ • UnicodeΛαϙʔτ͢ΔڥͰ͍Ζ͍ΖͳจࣈʹϚον • \s “whitespace character” ۭനจࣈʹϚον [ \t\r\n\f] • UnicodeΛαϙʔτ͢ΔڥͰUnicodeͷʮseparatorʯΧςΰϦͷͯ͢ͷจࣈʹϚον
υοτʢϐϦΦυʣ The Dot Matches (Almost) Any Character • վߦจࣈΛআ̍͘จࣈʹϚον •
“dot matches all”·ͨ“single line”Ϟʔυʢϓϩάϥϛϯάݴޠਖ਼نදݱΤ ϯδϯʹΑͬͯݺͼํҟͳΔʣΛࢦఆ͢ΔͱվߦจࣈΛؚΉҙͷ1จࣈʹ Ϛον • gr.yɺgrayɺgrayɺgr%yͳͲʹϚον • υοτڧྗʹͳΜͰϚον͢ΔͷͰ͍͗͢ͳ͍ • จࣈΫϥε൱ఆจࣈΫϥεΛΘΓʹ͏
ΞϯΧʔ Anchors • จࣈͰͳ͘ҐஔʹϚον • ^ • จࣈྻͷઌ಄ʹϚον • $
• จࣈྻͷඌʹϚον • ΄ͱΜͲͷਖ਼نදݱ“multi-line”Ϟʔυ͕͋Γɺ ^վߦͷޙΖɺ $վߦͷલʹϚον͢Δ • \b • ୯ޠڥքʹϚον • ୯ޠڥքͱ\wͰϚονͰ͖ΔจࣈͱɺͰ͖ͳ͍จࣈͷؒͷҐஔ
બ Alternation • ཧʢORʣ • cat|dog • About cats and
dogs • cat|dog|mouse| fi sh • ͖ͳ͚ͩͭͳ͛Δ͜ͱ͕Ͱ͖Δ • cat|dog food • cat·ͨdog foodʹϚον • cat food͔dog foodʹϚονͤ͞Δʹɺ(cat|dog) foodͷΑ͏ʹબΛάϧʔϓԽ͢Δ
܁Γฦ͠ Repetition • ΫΤενϣϯϚʔΫʮ?ʯ • Optional • colou?rcolor·ͨcolourʹϚον • ΞελϦεΫʮ*ʯ
• ̌ճҎ্ͷ܁Γฦ͠ • <[A-Za-z][A-Za-z0-9]*> • ଐੑ͕ͳ͍HTMLλάʹϚον • ϓϥεʮ+ʯ • ̍ճҎ্ͷ܁Γฦ͠ • Χοίʮ{n,m}ʯ • ࢦఆճͷ܁Γฦ͠ • \b[1-9][0-9]{3}b • 1000͔Β9999ͷࣈʹϚον • \b[1-9][0-9]{2,4}\b • 100͔Β99999ͷࣈʹϚον
άϧʔϓͱΩϟϓνϟ Grouping and Capturing • ΧοίͰғΉͱάϧʔϓԽ͞ΕΔ • άϧʔϓʹରͯ͠܁Γฦ͠ΛࢦఆͰ͖Δ • Set(Value)?
• Set·ͨSetValueʹϚον • ௨ৗͷؙΧοίΩϟϓνϟάϧʔϓΛ࡞͢Δ • Set(Value)?ͷਖ਼نදݱͰSetValue͕Ϛονͨ͠߹ɺάϧʔϓ̍ʹΞΫηε͢ΔͱValue͕औΓग़ͤΔ • Ωϟϓνϟ͕ඞཁͳ͍߹Set(?:Value)?ͱ͢ΔͱΩϟϓνϟ͠ͳ͍άϧʔϓ͕࡞Ͱ͖Δ • ؙΧοίͷޙͷΫΤενϣϯϚʔΫͱɺ̌ճҎ্ͷ܁Γฦ͠ͷࢦఆͷΫΤενϣϯϚʔΫΛࠞಉ͠ͳ͍Α͏ʹ ҙ
ޙํࢀর Backreferences • ΩϟϓνϟάϧʔϓͰΩϟϓνϟʢϚονʣͨ͠༰ʹϚον • ΩϟϓνϟάϧʔϓʹϚονͨ݁͠ՌΛ࠶ར༻Ͱ͖Δ • <([A-Z][A-Z0-9]*)\b[^>]*>.*?</\1> • HTMLλάʹϚονʢΩϟϓνϟάϧʔϓʹϚονͨ͠։࢝λάΛऴྃλάͰ
࠶ར༻͍ͯ͠Δʣ
໊લ͖άϧʔϓʢΩϟϓνϟʣͱޙํࢀর Named Groups and Backreferences • ΩϟϓνϟͷࢀরΛ൪߸Ͱཧ͢Δͷେมͩ͠ɺՃআͰͣΕΔͷͰ໊લΛ͚ΒΕΔ • ߏจʢ໊લ͖άϧʔϓʣ •
(?P<name>group) • ߏจʢޙํࢀরʣ • (?P=name) • <(?P<tag>[A-Z][A-Z0-9]*)\b[^>]*>.*?</(?P=tag)> • HTMLλάʹϚονʢ <([A-Z][A-Z0-9]*)\b[^>]*>.*?</\1>ͱಉ͡ʣ • ߏจʢ໊લ͖Ωϟϓνϟʢ.NETʣʣ • (?<name>group)·ͨ(?’name'group) • ߏจʢ໊લʹΑΔࢀরʢ.NETʣʣ • \k<name>·ͨ\k'name'
ઌಡΈͱޙಡΈ Lookaround (Lookahead/Lookback(Lookbehind)) • ಛघͳάϧʔϓͰɺΞϯΧʔͷΑ͏ʹϚονͨ݁͠ՌͷҐஔΛࢦఆ͢Δ • ʢྫʣ\d+(?=€) • ͷޙʹʮ€ʯ͕ଓ͘จࣈྻʹϚον •
1 turkey costs 30€ͷ30ʹϚον • ߏจʢߠఆઌಡΈʢPositive lookaheadʣʣ • X(?=Y) • ߏจʢ൱ఆઌಡΈʢNegative lookaheadʣʣ • X(?!Y) • ߏจʢߠఆޙಡΈʢPositive lookbehindʣʣ • (?<=Y)X • ߏจʢ൱ఆޙಡΈʢNegative lookbehindʣʣ • (?<!Y)X
References • Regular-Expressions.info https://www.regular-expressions.info/ • Swift Regex https://swiftregex.com/