from github to this gitea

vim regex lookaround.md

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+---
+alias: [ "vim regex lookahead", "vim regex lookbehind", "vim regex lookaround", "lookahead", "lookbehind", "lookaround" ]
+---
+up:: [[vim regex]]
+title:: "before and after matches"
+#informatique 
+
+---
+Allows to match pattern after (lookahead) or before (lookbehind) the current pattern.
+
+# Quick reference
+
+ - `\zs` starts the selection (everything before is searched for but not matched)
+ - `\ze` stop the selection (everything after is searched for but not matched)
+
+|            | positive | negative |
+| ---------- | -------- | -------- |
+| lookahead  |`@=`|`@!`| 
+| lookbehind |`@<=`|`@<!`| 
+
+# Exemples 
+
+> [!example] president (not (Macron|Hollande))
+> To match President if it is **not** `President Macron` or `President Hollande`.
+> Note that the match will select only `President` (else the regex is obvious).
+> `President\(Macron\|Hollande\)\@!`
+> Or, with verymagic mode 
+> `\vPresident(Macron|Hollande)@!`
+
+> [!example] python attributes, but not of self
+> Match any python attribute (a word after a dot), except attributes of `self` (attributes of an object from the object itself)
+> `\(self\)\@<!\.\zs\w\+`
+> or, with verymagic mode 
+> `\v(self)@<!.\zs\<+`
+> 
+