PetitParser

Originally Lukas Renggli has written PetitParser as part of his work on the Helvetia system.

Writing Parsers with PetitParser. page

START 29 YOUTUBE vgiJG3Vd6KU PetitParser Tutorial (Part 1)

PetitParser is a parsing framework different to many other popular parser generators. For example, it is not table based such as SmaCC or ANTLR. Instead it uses a unique combination of four alternative parser methodologies: scannerless parsers, parser combinators, Parsing Expression Grammars and packrat parsers. As such **PetitParser** is more powerful in what it can parse and it arguably fits better the dynamic nature of Smalltalk. Let’s have a quick look at these four parser methodologies:

1. *Scannerless Parsers* combine what is usually done by two independent tools (scanner and parser) into one. This makes writing a grammar much simpler and avoids common problems when grammars are composed. 1. *Parser Combinators* are building blocks for parsers modeled as a graph of composable objects; they are modular and maintainable, and can be changed, recomposed, transformed and reflected upon. 1. *Parsing Expression Grammars* (PEGs) provide ordered choice. Unlike in parser combinators, the ordered choice of PEGs always follows the first matching alternative and ignores other alternatives. Valid input always results in exactly one parse-tree, the result of a parse is never ambiguous. 1. *Packrat Parsers* give linear parse time guarantees and avoid common problems with left-recursion in PEGs.

* 9:56 – […] but the coolest thing is the approach to parsing not necessarily as a sequence of rules, but as a Composition of Objects * Building Modular Parsers. pdf * Layout Sensitive Parsing in Petit Parser Framework. pdf * SStDSL, eine DSL für Schnittstellen mit PetitParser. page , pdf * Optimizing Parser Combinators. acm * […] – https://scholar.google.com/scholar?hl=de&as_sdt=0%2C5&q=%22petit+parser%22+grammar+of+string&btnG= * PetitParser2 – GT4PetitParser2. page

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botwhytho — 30.11.2020 I just want to have some generic interfaces (to be sub-classed) defined for how to fetch from external sources and for how to parse them. My current source is trello cards in a specific list so a couple of api calls away, rather trivial. My formatting is very freeform but when I started I made sure I could at least parse it easily with some regex (or probably PetitParser). One line per time entry and a format similar to [Time - Range][space][description] Obviously this is not an ideal way to keep the data but figured it would be better to start collecting it somehow, and later analyze it. Gt seems like a pretty good platform for the analysis

tudor girba — 30.11.2020 Yes, PetitParser would likely be a good fit here you likely want: - an importer of Trello export (I guess they can export to something standard like JSON) - a model made out entities like: TimeRange, Space, Activity. This model is populated by the importer. - a parser that specializes the entries based on your notation (this is where PetitParser would work well). Based on this, the importer enriches the model. - views on the model

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# Link Detection

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We reorganized the PetitParser2 links. If you download the LepiterDocs repository (you can download it without Fossil as a zip file from https://mutabit.com/repos.fossil/LepiterDocs/zip) and load the "Libreta Base" note and run the "Create table of content" function in the page inspector [click (1) and then run (2) in the screenshot], we could share our PetitParser links. And yes, at some point we need a more fluid workflow for sharing our Lepiter/Web notes/documents.