go type_error ai_generated true

panic: send on receive-only channel

ID: go/channel-direction-mismatch

Also available as: JSON · Markdown · 中文
80%Fix Rate
80%Confidence
0Evidence
2024-12-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.18 active — — —
1.19 active — — —

Root Cause

Attempting to send on a channel that is declared as receive-only (<-chan), or receive on a send-only channel (chan<-). This is a compile-time error, but can occur if type assertions are used incorrectly at runtime.

generic

中文

尝试向声明为只接收（<-chan）的通道发送数据，或在只发送（chan<-）通道上接收。这是编译时错误，但如果类型断言使用不当，可能在运行时发生。

Workarounds

  1. 98% success 
    func producer(ch chan<- int) {
    ch <- 1
}

func consumer(ch <-chan int) {
    v := <-ch
    fmt.Println(v)
}

ch := make(chan int)
go producer(ch)
consumer(ch)
  2. 95% success 
    ch := make(chan int)

go func(ch chan<- int) {
    ch <- 42
}(ch)

v := <-ch
fmt.Println(v)

Dead Ends

Common approaches that don't work:

  1. 100% fail

    Type assertions cannot change channel direction; it's a static property.

  2. 100% fail

    The program will panic or fail to compile.