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27 lines
1.1 KiB
Markdown
27 lines
1.1 KiB
Markdown
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# Package `regex/syntax`
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Package `syntax` provides regular expressions parser as well as AST definitions.
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## Rationale
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There are several problems with the stdlib [regexp/syntax](https://golang.org/pkg/regexp/syntax/) package:
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1. It does several transformations during the parsing that make it
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hard to do any kind of syntax analysis afterward.
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2. The AST used there is optimized for the compilation and
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execution inside the [regexp](https://golang.org/pkg/regexp) package.
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It's somewhat complicated, especially in a way character ranges are encoded.
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3. It only supports [re2](https://github.com/google/re2/wiki/Syntax) syntax.
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This parser recognizes most PCRE operations.
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4. It's easier to extend this package than something from the standard library.
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This package does almost no assumptions about how generated AST is going to be used
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so it preserves as much syntax information as possible.
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It's easy to write another intermediate representation on top of it. The main
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function of this package is to convert a textual regexp pattern into a more
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structured form that can be processed more easily.
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