Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

urlDecode is partial

Open
#81 3 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
haskell

Research direction

Start by locating the urlDecode implementation and its callers, then reproduce the two ghci examples from the issue. Check how malformed percent escapes are currently handled and whether existing tests cover them; done should mean invalid input no longer raises the shown exception and valid URLs retain their current decoding behavior.

Written by the indexing model from the issue text.

Description

In ghci:

ghci > urlDecode "http://twitter.com/fred/statuses/200"
"http://twitter.com/fred/statuses/200"
ghci > urlDecode "http://twitter.com/%user_screen_name%/statuses/%id%"
"http://twitter.com/*** Exception: Char.digitToInt: not a digit 'u'

It would be vastly nicer if urlDecode's type was something like String -> Either String String.

Dominant language
Haskell
Stars
186
Forks
59
PR merge metrics
No merged PRs in 30d

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from haskell/HTTP

All issues in haskell/HTTP

Similar issues

More Haskell issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.