How to perform function call in debugger's Log Expression?

[Kentzo]

I'm trying to call the String() function on my struct, but cannot figure out if it's supported:

{s.String()}

{eval err: &{%!e(string=function calls not allowed without using 'call')}}

{call s.String()}

{eval err: [%!e(*scanner.Error=&{{ 5 1 6} expected 'EOF', found r})]}

[firelizzard18]

That sounds like there's an error in your code, or possibly an error in delve.

[Kentzo]

Sample that reproduces the problem:

Do I misunderstand how to call Go functions from log expressions?

[firelizzard18]

strings don't have a String() method. As you can see in this playground file trying to compile str.String() results in:

str.String undefined (type string has no field or method String)

Also I'm not 100% sure calling functions from log expressions works.

[Kentzo]

You're right regarding the strings.

Nevertheless, log expression is still broken:

[firelizzard18]

I don't think calls are supported in log points. The debugger - delve - handles parsing of the logpoint message and based on other issues I saw (related to eval, not logpoints) and the behavior I believe that delve simply doesn't have support for detecting "call ..." so it's attempting to evaluate that as if it's a Go expression and failing.