37 lines
988 B
Markdown
37 lines
988 B
Markdown
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# Guarded Regex
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This is a simple library for creating guarded regular expressions. Pattern matching in Java
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is pretty slow even with compiled regular expressions.
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Guarding them with a `startsWith()`, `endsWith()` or `contains()` can be an order of magnitude
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faster, but leads to an unfortunate spreading out of the logic across the pattern and the guard
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condition.
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Guarded regexes aims to fix this. Instead of code like
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```java
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Pattern pattern = Pattern.compile("[123]?foo(bar|baz){2,5}");
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void ifTheThingDoTheThing(String str) {
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if (str.contains("foo") && pattern.matcher(str).matches()) {
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doTheThing();
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}
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}
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```
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you get the more expressive variant
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```java
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GuardedRegex thingPredicate =
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GuardedRegexFactory.contains("foo", "[123]?foo(bar|baz){2,5}");
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void ifTheThingDoTheThing(String str) {
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if (thingPredicate.test(str)) {
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doTheThing();
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}
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}
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```
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## Central Classes
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* [GuardedRegexFactory](src/main/java/nu/marginalia/gregex/GuardedRegexFactory.java)
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