Editing Operator-precedence parser (section)

== Pratt parsing ==
{{external links|section|date=August 2023}}
Another precedence parser known as Pratt parsing was first described by [[Vaughan Pratt]] in the 1973 paper "Top Down Operator Precedence",<ref>Pratt, Vaughan. "[https://web.archive.org/web/20151223215421/http://hall.org.ua/halls/wizzard/pdf/Vaughan.Pratt.TDOP.pdf Top Down Operator Precedence]." ''Proceedings of the 1st Annual ACM SIGACT-SIGPLAN Symposium on Principles of Programming Languages'' (1973).</ref> based on [[Recursive descent parser|recursive descent]]. Though it predates precedence climbing, it can be viewed as a generalization of precedence climbing.<ref>{{cite web |last1=Norvell |first1=Theodore |title=Parsing Expressions by Recursive Descent |url=http://www.engr.mun.ca/~theo/Misc/pratt_parsing.htm |website=www.engr.mun.ca |quote=The purpose of this post is to [... start] with precedence climbing and refactoring it to use the command pattern until we arrive at a Pratt parser. [This is the author who coined the term "precedence climbing".]}}</ref>

Pratt designed the parser originally to implement the [[CGOL]] programming language, and it was treated in much more depth in a Masters Thesis under his supervision.<ref>Van De Vanter, Michael L. "[http://publications.csail.mit.edu/lcs/specpub.php?id=715 A Formalization and Correctness Proof of the CGOL Language System]." (Master's Thesis).  MIT Laboratory for Computer Science Technical Report MIT-LCS-TR-147 (Cambridge, Massachusetts).  1975.</ref>

Tutorials and implementations:
* [[Douglas Crockford]] based the JavaScript parser in [[JSLint]] on Pratt parsing.<ref>{{cite web|author=Crockford, D|title=Top Down Operator Precedence|date=2007-02-21|url=http://crockford.com/javascript/tdop/tdop.html}}</ref>
* Comparison between Python implementations of precedence climbing and Pratt parsing: [http://www.oilshell.org/blog/2016/11/01.html "Pratt Parsing and Precedence Climbing Are the Same Algorithm" (2016) by Andy Chu]
* Tutorial using [[Rust (programming language)|Rust]]: [https://matklad.github.io/2020/04/13/simple-but-powerful-pratt-parsing.html "Simple but Powerful Pratt Parsing" (2020) by Aleksey Kladov]
* Tutorial using [[Rust (programming language)|Rust]]: [https://williamr.dev/posts/pratt-parsing/ "The Pratt Parsing Technique" (2024) by William Rågstad]
* Tutorial using [[Python (programming language)|Python]]: [http://effbot.org/zone/simple-top-down-parsing.htm "Simple Top-Down Parsing in Python" (2008) by Fredrik Lundh] {{Webarchive|url=https://web.archive.org/web/20150228044653/http://effbot.org/zone/simple-top-down-parsing.htm |date=2015-02-28 }}
* Tutorial using [[Java (programming language)|Java]]: [http://journal.stuffwithstuff.com/2011/03/19/pratt-parsers-expression-parsing-made-easy/ "Pratt Parsers: Expression Parsing Made Easy" (2011) by Bob Nystrom, author of Crafting Interpreters]
* Implementation in [[C Sharp (programming language)|C#]]: [https://github.com/atifaziz/Gratt "Gratt: A Generic Vaughn Pratt's top-down operator precedence parser for .NET Standard"] (a [[Generic programming|generic]] version inspired by the Java implementation presented by Bob Nystrom in [http://journal.stuffwithstuff.com/2011/03/19/pratt-parsers-expression-parsing-made-easy/ "Pratt Parsers: Expression Parsing Made Easy"])