Allow users to list methods of struct/interface #2249
Comments
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In the meantime, the |
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What about a |
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I'm also interested. And I have found myself wanting this feature on more than one occasion. Specifically: Proposal:Add ability to list the public API of any variable/type and also the public api of any import. Problem statement:Whenever you are debugging using delve you want to know a number of things; For (a) we have Usage:Let's say you have a Go file like package main
import (
"compress/flate"
"net/http"
"time"
)
func main() {
_ = flate.BestSpeed
tomorrow := time.Hour * 24
req, _ := http.NewRequest("GET", "https://google.com", nil)
}You can then use the (dlv) ptype tomorrow
(dlv) ptype req
(dlv) ptype "compress/flate"And when you do so, the public API of the requested variables/types or package import will be printed. (dlv) ptype tomorrow
[
NAME: time.Duration
KIND: int64
SIGNATURE: [time.Duration]
FIELDS: []
METHODS: [
Hours func(time.Duration) float64
Microseconds func(time.Duration) int64
Milliseconds func(time.Duration) int64
Minutes func(time.Duration) float64
Nanoseconds func(time.Duration) int64
Round func(time.Duration, time.Duration) time.Duration
Seconds func(time.Duration) float64
String func(time.Duration) string
Truncate func(time.Duration, time.Duration) time.Duration
]
](dlv) ptype req
[
NAME: net/http.Request
KIND: struct
SIGNATURE: [*http.Request http.Request]
FIELDS: [
Method string
URL *url.URL
Proto string
ProtoMajor int
ProtoMinor int
... <truncated> ...
]
METHODS: [
AddCookie func(*http.Request, *http.Cookie)
BasicAuth func(*http.Request) (string, string, bool)
Clone func(*http.Request, context.Context) *http.Request
... <truncated> ...
]
](dlv) ptype "compress/flate"
[
NAME: compress/flate
CONSTANTS: [
BestCompression untyped int
BestSpeed untyped int
... <truncated> ...
]
VARIABLES: []
FUNCTIONS: [
NewReader(r io.Reader) io.ReadCloser
NewReaderDict(r io.Reader, dict []byte) io.ReadCloser
... <truncated> ...
]
TYPES: [
... <truncated> ...
Writer struct
(*Writer) Close() error
(*Writer) Flush() error
(*Writer) Reset(dst io.Writer)
(*Writer) Write(data []byte) (n int, err error)
CorruptInputError int64
(CorruptInputError) Error() string]
]Precedent:The struct complex {double real; double imag;} v;
(gdb) whatis v
type = struct complex
(gdb) ptype v
type = struct complex {
double real;
double imag;
}Implementation:The implementation would use the This proposal can be broken into two parts: I can avail any other information required to help people be able to evaluate this proposal. Thanks, |
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I don't know whether to make my proposal an independent issue? |
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Also a bit related to: #55 |
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@komuw perhaps the new functionality could be a flag passed to |
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@icholy I would also be fine with that idea. |
good idea, I found this issue for almost the same purpose, to print a complex data structure without the souce code |
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I need this feature, and I am trying to implement this. Now I have a problem to solve. Following is my testing: $ dlv debug main.go
Type 'help' for list of commands.
(dlv) b main.main
Breakpoint 1 set at 0x10cb87b for main.main() ./main.go:17
(dlv) c
> main.main() ./main.go:17 (hits goroutine(1):1 total:1) (PC: 0x10cb87b)
12: def int
13: }
14:
15: var _ Student = Student{}
16:
=> 17: func main() {
18: ss := Student{Name: "xxxx"}
19: fmt.Println(ss)
20: }
(dlv) types Student
*main.Student
main.Student
(dlv) ptype main.Student
struct main.Student <nil>
(dlv) ptype int
int <nil>
(dlv) main.Student is defined and printed by I just use I expect I think I can do a $ dlv debug main.go
Type 'help' for list of commands.
(dlv) b main.main
Breakpoint 1 set at 0x10cb87b for main.main() ./main.go:17
(dlv) ptype main.Student
struct main.Student
fields
0 Name string
1 Age int
2 Sex int
3 Address string
4 School string
5 abc int
6 def intProblem is
todo:
Next, I want to see how This modification is here: https://github.com/hitzhangjie/delve/tree/feat/ptype. using method1 mentioned above, now I can list the method's name (without parameter list). (dlv) ptype main.Student
struct main.Student
fields
0 Name string
1 Age int
2 Sex int
3 Address string
4 School string
5 abc int
6 def int
methods
String
Sing
Learn
<nil>After writing some code about DWARF, now it can list the parameter list (receiverType var is dropped) and return list: $ dlv debug main.go
Type 'help' for list of commands.
(dlv) ptype main.Student
struct main.Student
fields
0 Name string
1 Age int
2 Sex int
3 Address string
4 School string
5 abc int
6 def int
methods
func Learn(a int,b int) (~r2 error)
<nil> |
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I had given this a shot one year ago and got it somehow working as a proof of concept with bad code. when you do so, you get output like: (dlv) whatis -v f
===printVar:===
struct main.Fire {
fields:
HH main.Health
Age int64
Name string
Dist main.Distance
Day time.Time
methods:
Hello func(i int) string
MethodTwo func() int64
}
===printVar:===
main.Firewhatis -v hReq
===printVar:===
struct *net/http.Request {
fields:
Method string
URL *net/url.URL
Proto string
....
TLS *crypto/tls.ConnectionState
Cancel <-chan struct {}
Response *net/http.Response
methods:
BasicAuth func() (username string, password string, ok bool)
SetBasicAuth func(username string, password string)
...
Clone func(ctx context.Context) *net/http.Request
PostFormValue func(key string) string
Write func(w io.Writer) error
ParseMultipartForm func(maxMemory int64) error
Cookies func() []*net/http.Cookie
}
===printVar:===
*net/http.Request(dlv) whatis -v MyFn
===printVar:===
func(int, string, *uint64) void {
methods:
MethodOnFunc func() int64
}
===printVar:===
main.fnI don't have time to take it further than I did, so I'm just sharing whatever I have. |
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@komuw Thanks for your sharing, I'm willing to learn your code later...and contribute this. |
and others
It would be nice for developers to list all methods of a struct/interface in addition to its fields in dlv like python
dir(object).PS: though this expr doc says that dlv shows the concrete type of a interface, I also want to list all methods of a interface.
Additional information:
dlv version)?The text was updated successfully, but these errors were encountered: