Cgo - Stringer for C enum

Sonia Hamilton

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Dec 16, 2012, 7:25:13 AM12/16/12

to golan...@googlegroups.com

Using cgo I've implemented Stringer for a C enum.

It works, I'm just wondering if there's a better way than the following? For an enum with a bazillion members, it would be rather tedious...

type UriType int

const (
GNET_SNMP_URI_GET UriType = iota
GNET_SNMP_URI_NEXT
GNET_SNMP_URI_WALK
)

// Stringer for _Ctype_GNetSnmpUriType
//
// /usr/include/gsnmp/utils.h
//
// typedef enum
// {
//     GNET_SNMP_URI_GET,
//     GNET_SNMP_URI_NEXT,
//     GNET_SNMP_URI_WALK
// } GNetSnmpUriType;
func (uritype _Ctype_GNetSnmpUriType) String() string {
switch UriType(uritype) {
case GNET_SNMP_URI_GET:
    return "GNET_SNMP_URI_GET"
case GNET_SNMP_URI_NEXT:
    return "GNET_SNMP_URI_NEXT"
case GNET_SNMP_URI_WALK:
    return "GNET_SNMP_URI_WALK"
}
return "UNKNOWN GNetSnmpUriType"
}

--
Sonia

Sanjay

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Dec 16, 2012, 9:32:45 AM12/16/12

to golan...@googlegroups.com

I've done this in the past with a global array of strings and have the String function just index the array. It reduces the number of lines you have to write by 1... but I can't think of anything better without a preprocessing step.

Sanjay

minux

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Dec 16, 2012, 10:01:10 AM12/16/12

to Sonia Hamilton, golan...@googlegroups.com

I'd suggest you write a script/Go program to parse and generate the progrom for this problem

and let the computer do the hard work; there is not better approaches other than to make an

array of the strings and slightly shorten the String() method.

for example, the syscall package uses a perl script driven by mkall.sh to generate all kinds of

constants and even Go syscall interface functions directly from system (or even kernel source)

headers.

Mike Rosset

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Dec 17, 2012, 5:42:21 AM12/17/12

to minux, Sonia Hamilton, golang-nuts

Sonia pretty sure you can use C.CNetSnmpUriType vs the cgo internal
type of _Ctype_GNetSnmpUriType.

> --
>
>

minux

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Dec 17, 2012, 7:38:36 AM12/17/12

to Mike Rosset, Sonia Hamilton, golang-nuts

On Mon, Dec 17, 2012 at 6:42 PM, Mike Rosset <mike....@gmail.com> wrote:

Sonia pretty sure you can use C.CNetSnmpUriType vs the cgo internal
type of _Ctype_GNetSnmpUriType.

you can't directly attach method to C.XXX type, either you define a new Go type alias, or

use the internal type name.

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