JuliaLang/julia

Unexpected behavior due to implicit `convert` with `Char` and `Integer`

Open

#44,410 opened on Mar 2, 2022

View on GitHub
 (10 comments) (4 reactions) (0 assignees)Julia (5,773 forks)batch import
good first issuestrings

Repository metrics

Stars
 (48,709 stars)
PR merge metrics
 (Avg merge 20d 6h) (157 merged PRs in 30d)

Description

julia> append!([1, 2, 3], "4")
4-element Vector{Int64}:
  1
  2
  3
 52

is unintuitive (I would expect an error).

I think the mechanism for this is that it treats the "4" as a collection of Chars, and converts them into integers.

cc @jakobnissen @andrewrosemberg @raphaelsaavedra

Contributor guide

Research direction
Investigate the `append!` method for collections and trace how a string is interpreted as a collection of characters, possibly via `convert`. Look at the dispatch chain to understand why no error is thrown.
Tech stack
julia
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Julia
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70