golang/go

reflect: Value.Seq|Seq2 documentation and unexported value

Open

#74377 opened on Jun 25, 2025

View on GitHub
 (12 comments) (0 reactions) (0 assignees)Go (133,883 stars) (19,008 forks)batch import
DocumentationFixPendingSuggestedcompiler/runtimehelp wanted

Description

Go version

1.24

Output of go env in your module/workspace:

not relevant

What did you do?

Calling reflect.Value.Seq() panics if the value is unexported (CanInterface() returns false), but the documentation doesn't mention it.

What did you see happen?

It panics

What did you expect to see?

The documentation should explain that Seq() and Seq2() can be called if CanInterface() returns true, otherwise it panics. I guess we should add the same warning to Call() and CallSlice()

Contributor guide

Tech stack
go
Domain
documentation
Issue type
documentation
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.
under 1 hour
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
Go programmingreflect package basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
95
Research direction
Locate the documentation for Seq, Seq2, Call, and CallSlice methods in the reflect package's source code (likely in value.go). Add a note that these methods panic if CanInterface() returns false. Ensure consistency across all four methods. Also check if there are similar methods that might need the same warning. Review the discussion in the issue comments for any additional context. The fix involves adding a few lines to the method comments.