parsec: Monadic parser combinators
Parsec is designed from scratch as an industrial-strength parser library. It is simple, safe, well documented (on the package homepage), has extensive libraries, good error messages, and is fast. It is defined as a monad transformer that can be stacked on arbitrary monads, and it is also parametric in the input stream type.
The main entry point is the Text.Parsec module which provides defaults for parsing Character data.
The Text.ParserCombinators.Parsec module hierarchy contains the legacy parsec-2 API and may be removed at some point in the future.
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Modules
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- Text
- Text.Parsec
- ParserCombinators
- Text.ParserCombinators.Parsec
- Text.ParserCombinators.Parsec.Char
- Text.ParserCombinators.Parsec.Combinator
- Text.ParserCombinators.Parsec.Error
- Text.ParserCombinators.Parsec.Expr
- Text.ParserCombinators.Parsec.Language
- Text.ParserCombinators.Parsec.Perm
- Text.ParserCombinators.Parsec.Pos
- Text.ParserCombinators.Parsec.Prim
- Text.ParserCombinators.Parsec.Token
- Text.ParserCombinators.Parsec
Downloads
- parsec-3.1.18.0.tar.gz [browse] (Cabal source package)
- Package description (as included in the package)
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| Versions [RSS] | 2.0, 2.0.0.1, 2.1.0.0, 2.1.0.1, 3.0.0, 3.0.1, 3.1.0, 3.1.1, 3.1.2, 3.1.3, 3.1.4, 3.1.5, 3.1.6, 3.1.7, 3.1.8, 3.1.9, 3.1.10, 3.1.11, 3.1.12.0, 3.1.13.0, 3.1.14.0, 3.1.15.0, 3.1.15.1, 3.1.16.0, 3.1.16.1, 3.1.17.0, 3.1.18.0 |
|---|---|
| Change log | ChangeLog.md |
| Dependencies | base (>=4.12.0.0 && <4.22), bytestring (>=0.10.8.2 && <0.13), mtl (>=2.2.2 && <2.4), text (>=1.2.3.0 && <1.3 || >=2.0 && <2.2) [details] |
| Tested with | ghc ==8.6.5 || ==8.8.4 || ==8.10.7 || ==9.0.2 || ==9.2.8 || ==9.4.8 || ==9.6.4 || ==9.8.2 || ==9.10.1 || ==9.12.1 |
| License | BSD-2-Clause |
| Author | Daan Leijen <daan@microsoft.com>, Paolo Martini <paolo@nemail.it>, Antoine Latter <aslatter@gmail.com> |
| Maintainer | Oleg Grenrus <oleg.grenrus@iki.fi>, Herbert Valerio Riedel <hvr@gnu.org> |
| Category | Parsing |
| Home page | https://github.com/haskell/parsec |
| Bug tracker | https://github.com/haskell/parsec/issues |
| Source repo | head: git clone https://github.com/haskell/parsec |
| Uploaded | by phadej at 2025-01-05T00:08:05Z |
| Distributions | Arch:3.1.16.1, Fedora:3.1.16.1, FreeBSD:3.1.9 |
| Reverse Dependencies | 944 direct, 14181 indirect [details] |
| Downloads | 405099 total (36 in the last 30 days) |
| Rating | 2.75 (votes: 18) [estimated by Bayesian average] |
| Your Rating | |
| Status | Docs available [build log] Last success reported on 2025-01-05 [all 1 reports] |
Readme for parsec-3.1.18.0
[back to package description]Parsec 
Please refer to the package description on Hackage for more information.
A monadic parser combinator library, written by Daan Leijen. Parsec is designed from scratch as an industrial-strength parser library. It is simple, safe, well documented, has extensive libraries, good error messages, and is fast.
Some links:
- Parsec on Hackage, contains the generated documentation.
- The 2001 paper written by Daan Leijen, some what outdated (PDF, HTML, thanks to archive.org; and PDF, thanks to Microsoft Research).
- Using Parsec, chapter 16 of Real World Haskell.
- An introduction to the Parsec library on Kunigami's blog.
- An introduction to parsing text in Haskell with Parsec on Wilson's blog.
- Differences between Parsec and Attoparsec (Haskell's other prominent parser library) as explained in an answer on StackExchange.
- Differences between Parsec and Happy (Haskell's parser generator) as explained in two answers on separate StackExchange questions (1, 2).
- Differences between Parsec and Megaparsec (an advanced fork of Parsec) as explained in Megaparsec's README.
By analyzing Parsec's reverse dependencies on Hackage we can find open source project that make use of Parsec. For example bibtex, ConfigFile, csv and hjson.
Getting started
This requires a working version of cabal and ghci, which are part of any modern installation of Haskell, such as Haskell Platform.
First install Parsec.
cabal install parsec Below we show how a very simple parser that tests matching parentheses was made from GHCI (the interactive GHC environment), which we started with the ghci command).
Prelude> :m +Text.Parsec Prelude Text.Parsec> let parenSet = char '(' >> many parenSet >> char ')' :: Parsec String () Char Loading package transformers-0.3.0.0 ... linking ... done. Loading package array-0.5.0.0 ... linking ... done. Loading package deepseq-1.3.0.2 ... linking ... done. Loading package bytestring-0.10.4.0 ... linking ... done. Loading package mtl-2.1.3.1 ... linking ... done. Loading package text-1.1.1.3 ... linking ... done. Loading package parsec-3.1.5 ... linking ... done. Prelude Text.Parsec> let parens = (many parenSet >> eof) <|> eof Prelude Text.Parsec> parse parens "" "()" Right () Prelude Text.Parsec> parse parens "" "()(())" Right () Prelude Text.Parsec> parse parens "" "(" Left (line 1, column 2): unexpected end of input expecting "(" or ")" The Right () results indicate successes: the parentheses matched. The Left [...] result indicates a parse failure, and is detailed with an error message.
For a more thorough introduction to Parsec we recommend the links at the top of this README file.
Contributing
Issues (bugs, feature requests or otherwise feedback) may be reported in the Github issue tracker for this project.
Pull-requests are also welcome.
License
See the LICENSE file in the repository.
