Jun 10, 2019 · It is true that Parsec has chainl and chainr to parse chains of either left-associative or right-associative operations (i.e. a -> a -> a). So I could quite easily parse something like x + y ...

Aug 6, 2019 · Unfortunately lambda is not suitable for building a parsec Parser this way since you need to return a parsec.Value type not a boolean, so it will quickly lose its terseness. The design of parsec requires a Parser to act independently on an input stream without knowledge of any other Parser. To do this effectively a Parser must manage an index ...

Feb 21, 2011 · My understanding is that Parsec creates a nice DSL of writing parsers and Haskell makes it very easy and expressive. But parsing is such a standard/popular technology that deserves its own language, which outputs to multiple target languages. So when shall we use Parsec instead of, say, generating Haskell code from Bison/Antlr?

Jun 4, 2024 · It might seem that this question is a duplicate of this question, however either Parsec or the Indent library has changed since 2012 and none of the old examples I have found for the indent library ...

Nov 16, 2013 · We can see this in action by looking at the code for Parsec directly, which is somewhat more complex than my notion of Parser above. First we examine ParsecT. newtype ParsecT s u m a = ParsecT {unParser :: forall b .

The indents package for Haskell's Parsec provides a way to parse indentation-style languages (like Haskell and Python). It redefines the Parser type, so how do you use the token parser functions exported by Parsec's Text.Parsec.Token module, which are of the normal Parser type? Background. Parsec is a parser combinator library, whatever that means.

Jan 26, 2012 · You should use Parsec.Expr.buildExprParser; it is ideal for this purpose. You simply describe your operators, their precedence and associativity, and how to parse an atom, and the combinator builds the parser for you!

Apr 1, 2019 · I am trying to build Parsec_3.0 dedup workload on skylake server with gcc (Debian 6.3.0-18+deb9u1) 6.3.0. I managed to build streamcluster and canneal successfully without issues, however with dedup I get the error, when using same command: parsecmgmt -a build …

Oct 19, 2021 · There might be several reasons for these two errors, however the Parsec docs does not give possible solutions. In my case going to App & Features > Optional Features > Add Feature and then look for Media Feature Pack and install it, reboot and should work.

Ultimately, Parsec and Attoparsec cater to very different niches. The high-level difference is performance: if you need it, choose Attoparsec; if you don't, just go with Parsec. My usual heuristic is choosing Parsec for programming languages, configuration file formats and user input as well as almost anything I would otherwise do with a regex.