vimeo/psalm

intersection types and conditional types

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#6,942 opened on Nov 18, 2021

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 (18 comments) (0 reactions) (0 assignees)PHP (668 forks)batch import
Help wantedenhancementparser

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Description

consider https://psalm.dev/r/8e871b2851

two things:

  • the parser forces me to use parentheses around the intersection type. I would not expect that to be needed
  • since from the condition we know that A is an array, I don't see why A&array should be forbidden

Contributor guide

Research direction
Investigate why parentheses are required around intersection types in conditional types and why `A & array` is forbidden when `A` is known to be an array.
Tech stack
php
Domain
tooling
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
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
PHP
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60