Fast Parse
nearley
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| Fast Parse | nearley | |
|---|---|---|
| 4 | 3 | |
| 1,075 | 3,545 | |
| 0.4% | - | |
| 4.6 | 0.0 | |
| 10 days ago | 8 months ago | |
| Scala | JavaScript | |
| MIT License | MIT License |
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Fast Parse
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How do I remove the forward reference error in my parser? (20 lines)
Perhaps use Li Haoyi's fastparse instead? https://github.com/com-lihaoyi/fastparse
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Parse slightly dirty, poorly escaped XML
You might want to adapt Li Haoyi’s XML parser for fastparse.
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-🎄- 2021 Day 18 Solutions -🎄-
Mostly a mess of pattern matching. I really need to make some generic tree utilities. Haven't been able to find a decent parser combinator that works in Scala 3 (I usually use fastparse which depends heavily on Scala 2 macros, and scala-parser-combinators works in Scala 3, but I've had a lot of trouble getting it to not be too greedy), so I used the state monad from cats to parse at the bottom of the file, which I think turned out fairly nice.
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Parser generators vs. handwritten parsers: surveying major languages in 2021
Agreed! I would say that parser combinators are the sweet spot and the right choice in most cases.
Scala has them as well, e.g.: https://com-lihaoyi.github.io/fastparse/
And the good thing is, you don't have to learn a completely new language/syntax, you can use the host language's syntax and you have full IDE support as well.
nearley
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Writing a C compiler in 500 lines of Python
While I suspect I would learn more writing a tokenizer and parsing logic myself I find grammars much easier to read and maintain.
ANTLR is pretty good and is supported across several languages and something I had previously used for some quick Elasticsearch query syntax munging in Python. It also means you can often start from an already existing grammar.
The JS version of ANTLR didn't seem to work for me so for the SQL/JSONPath stuff ended up using the Moo lever and Nearly parser which was rather pleasant. https://nearley.js.org
- Parser generators vs. handwritten parsers: surveying major languages in 2021
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Applicative Parsing
Parsers in nearley.js [1] are written in a very readable EBNF-like DSL; then they get desugared down to a JS file that's a lot like your snippet.
[1] https://github.com/kach/nearley
What are some alternatives?
Parboiled2 - A macro-based PEG parser generator for Scala 2.10+
PEG.js - PEG.js: Parser generator for JavaScript
Scala Parser Combinators - simple combinator-based parsing for Scala. formerly part of the Scala standard library, now a separate community-maintained module
Jison - Bison in JavaScript.
atto - friendly little parsers
Chevrotain - Parser Building Toolkit for JavaScript
Scopt - command line options parsing for Scala
markdown-it - Markdown parser, done right. 100% CommonMark support, extensions, syntax plugins & high speed
Kaitai Struct - Kaitai Struct: declarative language to generate binary data parsers in C++ / C# / Go / Java / JavaScript / Lua / Nim / Perl / PHP / Python / Ruby
xml2js - XML to JavaScript object converter.
decline - A composable command-line parser for Scala.
parse5 - HTML parsing/serialization toolset for Node.js. WHATWG HTML Living Standard (aka HTML5)-compliant.