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Questions tagged [parsec]

Parsec is a parser library for the Haskell programming language.

3
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2answers
169 views

CodeWars - Three-pass compiler for arithmetic expressions

I'm looking for feedback on my solution to the Tiny Three-Pass Compiler kata on CodeWars. The kata is to implement a compiler for an arithmetic language in three passes - parsing to an AST, constant ...
1
vote
1answer
66 views

Mail merge (Parsec string formatting) example

My intent is to perform "mail merge" where I can write strings like "hi <<name>>" and format them according to a ...
3
votes
1answer
258 views

Haskell Parsec library implementation in Scala

I've been developing a compiler for a programming language I'm working on in Scala, and after having used Haskell's Parsec a lot for this sort of thing in the past I decided to reimplement the library ...
1
vote
1answer
57 views

Inefficient Parsec parser to skip unreachable block

In a parser written with Parsec 3.1.11, I have a performance issue with parsing (or better, skipping) the unreachable branch of a if-then-else statement. The syntax to be parsed is as follows: ...
3
votes
1answer
233 views

Haskell Parsec parser of Verilog-style number literals

I've set myself the task to write a function that parses Verilog-style number literals. In Verilog, numbers are written like this: 8'b10101100, ...
4
votes
1answer
95 views

Multiple base numbers parser

This code is a Parser that parses numbers according to R5RS. #b1001 - binary #o2127 - octal #h02d - hexadecimal #d1231 - decimal 3923 - decimal It is working ...
3
votes
0answers
252 views

Haskell s-expression parser and quasiquoter

There are a number of questions on this site about s-expression parsing: e.g., Calculator parsing S-expressions and Code from "Write Yourself a Scheme in 48 Hours" tutorial. However, these ...
5
votes
1answer
452 views

Python tokenizer in Haskell + Parsec

I wrote a tokenizer/lexer (difference?) for Python in Haskell: this is my code on GitHub. I already tested it out with some of CPython's standard library scripts, and it doesn't fail. However, it ...
2
votes
1answer
77 views

Parsing a component of a regex followed by an optional quantifier character

I have a piece of parsec code that parses a unit optionally followed by ?, + or ...
3
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1answer
123 views

Parsing characters with parsec

I am trying to parse escape sequences as well as plain characters. Can this be made more succinct? ...
3
votes
0answers
77 views

Generation and parsing of English numerals (cardinal and ordinal)

I need to use the English numerals (American) in Haskell, so I looked for a library that did it. I have not found one, therefore I developed the program that I am presenting here. There are actually ...
1
vote
1answer
57 views

Parsec for primes and fibs

I decided to spend some time working with parsec. I've written some code to check for primality and for whether something is a Fibonacci number. I'm mainly hoping for feedback on readability, but if ...
1
vote
1answer
201 views

Assorted Date Parser

I've written a date parser that parses different types of dates using Parsec. Credit for the original problem goes to here. The following formats are as such: ...
1
vote
0answers
434 views

Readability of a point-free applicative parser

I am writing an applicative parser, which you can think of as a minimal Parsec, just to educate myself. I got started with the excellent tutorial from this StackOverflow answer. Here is the relevant ...
5
votes
1answer
249 views

Using Parsec for simple arithmetic language

I've been reading Types and Programming Languages and I wanted to try to implement the first language in Haskell to understand it properly I have barely written any Haskell before and not used Parsec ...
1
vote
1answer
351 views

block comment parser implementation for “monadic parser combinators”

I'm reading monadic parser combinators. On the page 23, they leave an exercise for defining a Gofer block comment parser, and I try to implement it in Haskell. My code is here: ...
6
votes
1answer
751 views

Using Parsec for lexing&parsing

I'm creating list of Tokens from input [Char] stream using Parsec v3. The definition of Token...
14
votes
2answers
4k views

Parsing strings with escaped characters using Parsec

I have been working through the exercises in a Write Yourself a Scheme in 48 Hours/Parsing and hacked together something to get parseString to comprehend escaped characters. Also had some inspiration ...
6
votes
2answers
850 views

INI File Parser in Haskell

I'm learning Haskell at the moment, and have just written my first useful module - a parser fo INI files. I used Parsec. I'd like to know what can be improved here - or maybe I did some things ...
8
votes
1answer
816 views

First attempt at a SVG parser

I figured it's about time to jump into some Haskell, so here's a first attempt at an oddly specific SVG parser: ...