Is there any way to see a struct's methods while paused in the debugger?
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If I set a breakpoint in my Go code and pause execution, is there any way I can tell which methods a struct has attached to it?
Alternately, is there any way I can see which interfaces a struct implements while I am paused in the debugger?
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Hi,
Could you please elaborate a bit? If you initialized a struct, you can use Evaluate Expression https://www.jetbrains.com/go/guide/tips/evaluate-expression/ and complete methods. Otherwise, you can use code navigation in GoLand to see which interfaces are implemented.
Hello,
I have some write this you can read this
In Go, when you set a breakpoint in your code and pause execution, you can use the Go debugger (
delveorgdb) to inspect the methods attached to a struct and the interfaces it implements.To view the methods attached to a struct while paused in the debugger:
Using
delveDebugger: If you are using thedelvedebugger, you can use theptypecommand followed by the struct variable name to print the type information, including its methods.For example:
(dlv) ptype myStructVariable
Using
gdbDebugger: If you are using thegdbdebugger with the Golang plugin, you can use theptypecommand followed by the struct variable name to print the type information.For example:
(gdb) ptype myStructVariable
Additionally, remember that Go is a statically-typed language, and the information about a struct's methods and interfaces is known at compile time. While debugging, you can inspect this information using the debugger as described above.
If you prefer to obtain this information programmatically from your Go code itself, you can use the
reflectpackage to introspect the methods and interfaces of a struct at runtime. However, this approach does not involve the debugger and would require additional code and complexity.The link you provided for "evaluate expression" does not work. It displays a page showing "What you are looking for either does not exist or is not supposed to be displayed here."
I can reverse-engineer the code to try to understand which methods are implemented on a given struct, but for very complex code this is not feasible, particularly because sometimes due to composition, etc, the actual methods are extremely difficult to predict and must be viewed at run-time.
In the attached image, I am trying to determine if myStruct implements myInterface, at run time. This is an extremely simplified example.
If I type the name of the struct into the "Evaluate Expression" box, followed by a period (.) is does show me all methods defined on the struct, so I guess that is helpful. I guess another option is to use reflect.Type.Implements() to see if myStruct implements myInterface.
I hope this helps clarify my question.
Hi,
Sorry, I've fixed the link that I provided in the previous message.
You're right, the way is to use reflection Type.Implements but reflect package should be imported in your application so you can use it in Evaluate Expression area.
Unfortunately, I cannot share any other ways to do it and debugger doesn't have a special implementation to handle it.
Thank you for the updated link Daniil and for the information. Also thank you Thuongchodoisl for the comment and information.