Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
builtin: extract vlib/builtin/result.v from vlib/builtin/option.v
- Loading branch information
Showing
2 changed files
with
125 additions
and
116 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,115 @@ | ||
| // Copyright (c) 2019-2023 Alexander Medvednikov. All rights reserved. | ||
| // Use of this source code is governed by an MIT license | ||
| // that can be found in the LICENSE file. | ||
| module builtin | ||
|
|
||
| // IError holds information about an error instance | ||
| pub interface IError { | ||
| // >> Hack to allow old style custom error implementations | ||
| // TODO: remove once deprecation period for `IError` methods has ended | ||
| msg string | ||
| code int // << | ||
| msg() string | ||
| code() int | ||
| } | ||
|
|
||
| struct _result { | ||
| is_error bool | ||
| err IError = none__ | ||
| // Data is trailing after err | ||
| // and is not included in here but in the | ||
| // derived Result_xxx types | ||
| } | ||
|
|
||
| [markused] | ||
| fn _result_ok(data voidptr, mut res _result, size int) { | ||
| unsafe { | ||
| *res = _result{} | ||
| // use err to get the end of ResultBase and then memcpy into it | ||
| vmemcpy(&u8(&res.err) + sizeof(IError), data, size) | ||
| } | ||
| } | ||
|
|
||
| // str returns the message of IError | ||
| pub fn (err IError) str() string { | ||
| return match err { | ||
| None__ { | ||
| 'none' | ||
| } | ||
| Error { | ||
| err.msg() | ||
| } | ||
| MessageError { | ||
| err.msg() | ||
| } | ||
| else { | ||
| // >> Hack to allow old style custom error implementations | ||
| // TODO: remove once deprecation period for `IError` methods has ended | ||
| // old_error_style := unsafe { voidptr(&err.msg) != voidptr(&err.code) } // if fields are not defined (new style) they don't have an offset between | ||
| // << | ||
| '${err.type_name()}: ${err.msg()}' | ||
| } | ||
| } | ||
| } | ||
|
|
||
| // Error is the empty default implementation of `IError`. | ||
| pub struct Error {} | ||
|
|
||
| pub fn (err Error) msg() string { | ||
| return '' | ||
| } | ||
|
|
||
| pub fn (err Error) code() int { | ||
| return 0 | ||
| } | ||
|
|
||
| // MessageError is the default implementation of the `IError` interface that is returned by the `error()` function | ||
| struct MessageError { | ||
| pub: | ||
| msg string | ||
| code int | ||
| } | ||
|
|
||
| // msg returns the message of MessageError | ||
| pub fn (err MessageError) msg() string { | ||
| if err.code > 0 { | ||
| return '${err.msg}; code: ${err.code}' | ||
| } | ||
| return err.msg | ||
| } | ||
|
|
||
| // code returns the code of MessageError | ||
| pub fn (err MessageError) code() int { | ||
| return err.code | ||
| } | ||
|
|
||
| [unsafe] | ||
| pub fn (err &MessageError) free() { | ||
| unsafe { err.msg.free() } | ||
| } | ||
|
|
||
| [if trace_error ?] | ||
| fn trace_error(x string) { | ||
| eprintln('> ${@FN} | ${x}') | ||
| } | ||
|
|
||
| // error returns a default error instance containing the error given in `message`. | ||
| // Example: if ouch { return error('an error occurred') } | ||
| [inline] | ||
| pub fn error(message string) IError { | ||
| trace_error(message) | ||
| return &MessageError{ | ||
| msg: message | ||
| } | ||
| } | ||
|
|
||
| // error_with_code returns a default error instance containing the given `message` and error `code`. | ||
| // Example: if ouch { return error_with_code('an error occurred', 1) } | ||
| [inline] | ||
| pub fn error_with_code(message string, code int) IError { | ||
| trace_error('${message} | code: ${code}') | ||
| return &MessageError{ | ||
| msg: message | ||
| code: code | ||
| } | ||
| } |