Re: Re: What do you think about a C# 6 like nameof() expression for
> I’m not sure I understand what you mean by “false-positive” in this
instance.
Was referring to
const x = nameof y; // "y"
const y = 1;
Where ```y``` is ```undefined``` an error is not expected to be thrown? Is
```y``` declared globally, using ```const``` or ```let```, or not at all?
The use case described by OP
function func1(param1, param2, param3, userName, param4, param5) {
if (userName == undefined) {
throw new ArgumentNullError(nameof userName); // `ArgumentNullError`
is a custom error, derived from `Error`, composes error message like
"Argument cannot be null: userName".
}
checks if ```userName``` was ```undefined``` before using ```nameof```. If
error checking is a substantial portion of the proposal, why should an
error (```y``` being ```undefined``` though referenced) be ignored when
referencing an undefined identifier though concentrate on coercing a name
from a different potentially undefined property?
Consider this case:
> ```
> const someObject = { value: 1 };
> function setValue(value /*1*/) {
> if (typeof value /*2*/ !== "number") throw new TypeError(`Number
> expected: ${nameof value /*3*/}`);
> someObject["value" /*4*/] = value /*5*/;
> }
> ```
If you rename the parameter `value` of the function `setValue` in an editor
> with a rename refactoring, you want to rename the symbols at 1, 2, 3, and
> 5, but not the string at 4.
Not gathering the purpose or value of ```nameof``` usage in that case. If
the value is not a "number" then why does the value or name matter?
Since the primary use case appears to be an editor environment, why cannot
the editor be programmed to recognize the custom JavaScript ```nameof
function or operator? Then it would not matter if this board concurred with
the ```nameof``` functionality or not. Both CLI and GUI editors (and
JavaScript) are generally extensible. FWIW, some time ago incorporated
features into gedit for HTML templates; should be a similar process to
create custom scripts for the various editor environments where users rely
on such programs for code composition; now simply write the code by hand
and test in different environments, without taking the time to customize or
rely on an editor - take the time to test the code where the code will
actually be run where errors, if any, can be evaluated in the context in
which a specific output is expected. To each their own. What needs to be
implemented outside of what the users which advocate for ```nameof```
cannot implement themselves?
As mentioned earlier do not rely on "an editor with name refactoring" to
compose code. The code has to be tested (outside of the editor
environments) anyway. Test the code itself, here, not the editor.
On Fri, Jun 14, 2019 at 9:49 PM Ron Buckton
wrote:
> I’m not sure I understand what you mean by “false-positive” in this
> instance.
>
>
>
> Consider this case:
>
>
>
> ```
>
> const someObject = { value: 1 };
>
> function setValue(value /*1*/) {
>
> if (typeof value /*2*/ !== "number") throw new TypeError(`Number
> expected: ${nameof value /*3*/}`);
>
> someObject["value" /*4*/] = value /*5*/;
> }
>
> ```
>
>
>
> If you rename the parameter `value` of the function `setValue` in an
> editor with a rename refactoring, you want to rename the symbols at 1, 2,
> 3, and 5, but not the string at 4.
>
>
>
> Ron
>
>
>
> *From:* guest271314
> *Sent:* Friday, June 14, 2019 2:43 PM
> *To:* Ron Buckton
> *Cc:* es-discuss@mozilla.org
> *Subject:* Re: Re: What do you think about a C# 6 like nameof()
> expression for
>
>
>
> How is that behaviour related to the use cases presented by OP? Would such
> behaviour not lead to false-positive relevant to the 2 use cases?
>
>
>
> On Fri, Jun 14, 2019 at 9:36 PM Ron Buckton
> wrote:
>
> > `nameof whatever` → `Object.keys({ whatever })[0]`, but I'm a bit
> confused why it'd be better to type `nameof foo` in code, rather than
> `'foo'` - if you change `foo` to `bar`, you have to change both of them
> anyways.
>
>
>
> If you are using an editor that supports rename refactoring, its generally
> easier to rename the symbol `foo` and have all references (including
> `nameof foo`) be updated. You cannot safely automatically rename `'foo'` to
> `'bar'` since an editor or language service cannot guarantee that by the
> string `'foo'` you meant “the text of the identifier `foo`”.
>
>
>
> *From:* es-discuss *On Behalf Of *Jordan
> Harband
> *Sent:* Friday, June 14, 2019 2:29 PM
> *To:* guest271314
> *Cc:* es-discuss
> *Subject:* Re: Re: What do you think about a C# 6 like nameof()
> expression for
>
>
>
> `nameof whatever` → `Object.keys({ whatever })[0]`, but I'm a bit confused
> why it'd be better to type `nameof foo` in code, rather than `'foo'` - if
> you change `foo` to `bar`, you have to change both of them anyways.
>
>
>
> On Fri, Jun 14, 2019 at 1:31 PM guest271314 wrote:
>
> Am neither for nor against the proposal. Do not entertain "like"s or
> "dislike"s in any field of endeavor. Am certainly not in a
RE: Re: What do you think about a C# 6 like nameof() expression for
I’m not sure I understand what you mean by “false-positive” in this instance.
Consider this case:
```
const someObject = { value: 1 };
function setValue(value /*1*/) {
if (typeof value /*2*/ !== "number") throw new TypeError(`Number expected:
${nameof value /*3*/}`);
someObject["value" /*4*/] = value /*5*/;
}
```
If you rename the parameter `value` of the function `setValue` in an editor
with a rename refactoring, you want to rename the symbols at 1, 2, 3, and 5,
but not the string at 4.
Ron
From: guest271314
Sent: Friday, June 14, 2019 2:43 PM
To: Ron Buckton
Cc: es-discuss@mozilla.org
Subject: Re: Re: What do you think about a C# 6 like nameof() expression for
How is that behaviour related to the use cases presented by OP? Would such
behaviour not lead to false-positive relevant to the 2 use cases?
On Fri, Jun 14, 2019 at 9:36 PM Ron Buckton
mailto:ron.buck...@microsoft.com>> wrote:
> `nameof whatever` → `Object.keys({ whatever })[0]`, but I'm a bit confused
> why it'd be better to type `nameof foo` in code, rather than `'foo'` - if you
> change `foo` to `bar`, you have to change both of them anyways.
If you are using an editor that supports rename refactoring, its generally
easier to rename the symbol `foo` and have all references (including `nameof
foo`) be updated. You cannot safely automatically rename `'foo'` to `'bar'`
since an editor or language service cannot guarantee that by the string `'foo'`
you meant “the text of the identifier `foo`”.
From: es-discuss
mailto:es-discuss-boun...@mozilla.org>> On
Behalf Of Jordan Harband
Sent: Friday, June 14, 2019 2:29 PM
To: guest271314 mailto:guest271...@gmail.com>>
Cc: es-discuss mailto:es-discuss@mozilla.org>>
Subject: Re: Re: What do you think about a C# 6 like nameof() expression for
`nameof whatever` → `Object.keys({ whatever })[0]`, but I'm a bit confused why
it'd be better to type `nameof foo` in code, rather than `'foo'` - if you
change `foo` to `bar`, you have to change both of them anyways.
On Fri, Jun 14, 2019 at 1:31 PM guest271314
mailto:guest271...@gmail.com>> wrote:
Am neither for nor against the proposal. Do not entertain "like"s or "dislike"s
in any field of endeavor. Am certainly not in a position to prohibit anything
relevant JavaScript. Do what thou wilt shall be the whole of the Law.
Have yet to view a case where code will be "broken" by ```nameof``` not being a
JavaScript feature. "robustness", as already mentioned, is a subjective
adjective that is not capable of being objectively evaluated as to code itself.
That description is based on preference or choice.
In lieu of the proposal being specificed, use the posted code example of
```Object.keys()``` that "works".
```
function func1({userName = void 0} = {}) {
console.assert(userName !== undefined, [{userName}, 'property needs to be
defined'])
}
```
provides a direct indication that the property value is required to be defined.
Note that the example code posted thus far does not first check if
```options``` is passed at all, for which ```nameof``` will not provide any
asssitance.
Usually try to meet requirement by means already available in FOSS browsers.
Have no interest in TypeScript or using an IDE.
FWIW, have no objection to the proposal.
On Fri, Jun 14, 2019 at 7:53 PM Stas Berkov
mailto:stas.ber...@gmail.com>> wrote:
guest271314, what is you point against `nameof` feature?
If you don't like it - don't use it. Why prohibit this feature for
those who find it beneficial?
I see `nameof` beneficial in following cases
Case 1. Function guard.
```
function func1(options) {
...
if (options.userName == undefined) {
throw new ParamNullError(nameof options.userName); //
`ParamNullError` is a custom error, derived from `Error`, composes
error message like "Parameter cannot be null: userName".
// `Object.keys({options.userName})[0]` will not work here
}
}
```
Case 2. Accessing property extended info
Those ES functions that accept field name as string.
e.g.
```
const descriptor1 = Object.getOwnPropertyDescriptor(object1, 'property1');
```
vs
```
const descriptor1 = Object.getOwnPropertyDescriptor(object1, nameof
object1.property1);
// `Object.keys({options1.property1})[0]` will not work here
```
2nd variant (proposed) has more chances not to be broken during
refactoring (robustness).
It would make devs who use IDE more productive and make their life
easier. Why not give them such possiblity and make them happy?
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
Re: Re: What do you think about a C# 6 like nameof() expression for
Fri, 14 jun 2019 - 18:29, Jordan Harband wrote:
>
> `nameof whatever` → `Object.keys({ whatever })[0]`, but I'm a bit confused
> why it'd be better to type `nameof foo` in code, rather than `'foo'` - if you
> change `foo` to `bar`, you have to change both of them anyways.
>
Exactly, if you already have the name of the property beforehand in
design time why not write it as a string literal
Again, the only justifiable use case is refactoring tools, but even
today that can be arranged with static code analysis
You can safe guard a string literal to be a property of a type in
Typescript with a bit of handwork
``` ts
interface Options {
userName?: string;
}
// If you change the property in the interface without changing here, Typescript
// will raise a error informing that 'userName' is not a valid key of Options
const userNameKey: keyof Options = 'userName';
if (options.userName === undefined) {
throw new ParamNullError(userNameKey);
}
```
--
Atenciosamente,
Augusto Borges de Moura
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
Re: Re: What do you think about a C# 6 like nameof() expression for
How is that behaviour related to the use cases presented by OP? Would such
behaviour not lead to false-positive relevant to the 2 use cases?
On Fri, Jun 14, 2019 at 9:36 PM Ron Buckton
wrote:
> > `nameof whatever` → `Object.keys({ whatever })[0]`, but I'm a bit
> confused why it'd be better to type `nameof foo` in code, rather than
> `'foo'` - if you change `foo` to `bar`, you have to change both of them
> anyways.
>
>
>
> If you are using an editor that supports rename refactoring, its generally
> easier to rename the symbol `foo` and have all references (including
> `nameof foo`) be updated. You cannot safely automatically rename `'foo'` to
> `'bar'` since an editor or language service cannot guarantee that by the
> string `'foo'` you meant “the text of the identifier `foo`”.
>
>
>
> *From:* es-discuss * On Behalf Of *Jordan
> Harband
> *Sent:* Friday, June 14, 2019 2:29 PM
> *To:* guest271314
> *Cc:* es-discuss
> *Subject:* Re: Re: What do you think about a C# 6 like nameof()
> expression for
>
>
>
> `nameof whatever` → `Object.keys({ whatever })[0]`, but I'm a bit confused
> why it'd be better to type `nameof foo` in code, rather than `'foo'` - if
> you change `foo` to `bar`, you have to change both of them anyways.
>
>
>
> On Fri, Jun 14, 2019 at 1:31 PM guest271314 wrote:
>
> Am neither for nor against the proposal. Do not entertain "like"s or
> "dislike"s in any field of endeavor. Am certainly not in a position to
> prohibit anything relevant JavaScript. Do what thou wilt shall be the whole
> of the Law.
>
> Have yet to view a case where code will be "broken" by ```nameof``` not
> being a JavaScript feature. "robustness", as already mentioned, is a
> subjective adjective that is not capable of being objectively evaluated as
> to code itself. That description is based on preference or choice.
>
>
>
> In lieu of the proposal being specificed, use the posted code example of
> ```Object.keys()``` that "works".
>
>
>
> ```
>
> function func1({userName = void 0} = {}) {
> console.assert(userName !== undefined, [{userName}, 'property needs to
> be defined'])
> }
>
> ```
>
>
>
> provides a direct indication that the property value is required to be
> defined. Note that the example code posted thus far does not first check if
> ```options``` is passed at all, for which ```nameof``` will not provide any
> asssitance.
>
>
>
> Usually try to meet requirement by means already available in FOSS
> browsers. Have no interest in TypeScript or using an IDE.
>
>
>
> FWIW, have no objection to the proposal.
>
>
>
> On Fri, Jun 14, 2019 at 7:53 PM Stas Berkov wrote:
>
> guest271314, what is you point against `nameof` feature?
>
> If you don't like it - don't use it. Why prohibit this feature for
> those who find it beneficial?
>
> I see `nameof` beneficial in following cases
>
> Case 1. Function guard.
> ```
> function func1(options) {
> ...
>if (options.userName == undefined) {
>throw new ParamNullError(nameof options.userName); //
> `ParamNullError` is a custom error, derived from `Error`, composes
> error message like "Parameter cannot be null: userName".
> // `Object.keys({options.userName})[0]` will not work here
>}
> }
> ```
>
> Case 2. Accessing property extended info
> Those ES functions that accept field name as string.
> e.g.
> ```
> const descriptor1 = Object.getOwnPropertyDescriptor(object1, 'property1');
> ```
> vs
> ```
> const descriptor1 = Object.getOwnPropertyDescriptor(object1, nameof
> object1.property1);
> // `Object.keys({options1.property1})[0]` will not work here
> ```
> 2nd variant (proposed) has more chances not to be broken during
> refactoring (robustness).
>
> It would make devs who use IDE more productive and make their life
> easier. Why not give them such possiblity and make them happy?
>
> ___
> es-discuss mailing list
> es-discuss@mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
>
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
RE: Re: What do you think about a C# 6 like nameof() expression for
> `nameof whatever` → `Object.keys({ whatever })[0]`, but I'm a bit confused
> why it'd be better to type `nameof foo` in code, rather than `'foo'` - if you
> change `foo` to `bar`, you have to change both of them anyways.
If you are using an editor that supports rename refactoring, its generally
easier to rename the symbol `foo` and have all references (including `nameof
foo`) be updated. You cannot safely automatically rename `'foo'` to `'bar'`
since an editor or language service cannot guarantee that by the string `'foo'`
you meant “the text of the identifier `foo`”.
From: es-discuss On Behalf Of Jordan Harband
Sent: Friday, June 14, 2019 2:29 PM
To: guest271314
Cc: es-discuss
Subject: Re: Re: What do you think about a C# 6 like nameof() expression for
`nameof whatever` → `Object.keys({ whatever })[0]`, but I'm a bit confused why
it'd be better to type `nameof foo` in code, rather than `'foo'` - if you
change `foo` to `bar`, you have to change both of them anyways.
On Fri, Jun 14, 2019 at 1:31 PM guest271314
mailto:guest271...@gmail.com>> wrote:
Am neither for nor against the proposal. Do not entertain "like"s or "dislike"s
in any field of endeavor. Am certainly not in a position to prohibit anything
relevant JavaScript. Do what thou wilt shall be the whole of the Law.
Have yet to view a case where code will be "broken" by ```nameof``` not being a
JavaScript feature. "robustness", as already mentioned, is a subjective
adjective that is not capable of being objectively evaluated as to code itself.
That description is based on preference or choice.
In lieu of the proposal being specificed, use the posted code example of
```Object.keys()``` that "works".
```
function func1({userName = void 0} = {}) {
console.assert(userName !== undefined, [{userName}, 'property needs to be
defined'])
}
```
provides a direct indication that the property value is required to be defined.
Note that the example code posted thus far does not first check if
```options``` is passed at all, for which ```nameof``` will not provide any
asssitance.
Usually try to meet requirement by means already available in FOSS browsers.
Have no interest in TypeScript or using an IDE.
FWIW, have no objection to the proposal.
On Fri, Jun 14, 2019 at 7:53 PM Stas Berkov
mailto:stas.ber...@gmail.com>> wrote:
guest271314, what is you point against `nameof` feature?
If you don't like it - don't use it. Why prohibit this feature for
those who find it beneficial?
I see `nameof` beneficial in following cases
Case 1. Function guard.
```
function func1(options) {
...
if (options.userName == undefined) {
throw new ParamNullError(nameof options.userName); //
`ParamNullError` is a custom error, derived from `Error`, composes
error message like "Parameter cannot be null: userName".
// `Object.keys({options.userName})[0]` will not work here
}
}
```
Case 2. Accessing property extended info
Those ES functions that accept field name as string.
e.g.
```
const descriptor1 = Object.getOwnPropertyDescriptor(object1, 'property1');
```
vs
```
const descriptor1 = Object.getOwnPropertyDescriptor(object1, nameof
object1.property1);
// `Object.keys({options1.property1})[0]` will not work here
```
2nd variant (proposed) has more chances not to be broken during
refactoring (robustness).
It would make devs who use IDE more productive and make their life
easier. Why not give them such possiblity and make them happy?
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
Re: Re: What do you think about a C# 6 like nameof() expression for
`nameof whatever` → `Object.keys({ whatever })[0]`, but I'm a bit confused
why it'd be better to type `nameof foo` in code, rather than `'foo'` - if
you change `foo` to `bar`, you have to change both of them anyways.
On Fri, Jun 14, 2019 at 1:31 PM guest271314 wrote:
> Am neither for nor against the proposal. Do not entertain "like"s or
> "dislike"s in any field of endeavor. Am certainly not in a position to
> prohibit anything relevant JavaScript. Do what thou wilt shall be the whole
> of the Law.
>
> Have yet to view a case where code will be "broken" by ```nameof``` not
> being a JavaScript feature. "robustness", as already mentioned, is a
> subjective adjective that is not capable of being objectively evaluated as
> to code itself. That description is based on preference or choice.
>
> In lieu of the proposal being specificed, use the posted code example of
> ```Object.keys()``` that "works".
>
> ```
> function func1({userName = void 0} = {}) {
> console.assert(userName !== undefined, [{userName}, 'property needs to
> be defined'])
> }
> ```
>
> provides a direct indication that the property value is required to be
> defined. Note that the example code posted thus far does not first check if
> ```options``` is passed at all, for which ```nameof``` will not provide any
> asssitance.
>
> Usually try to meet requirement by means already available in FOSS
> browsers. Have no interest in TypeScript or using an IDE.
>
> FWIW, have no objection to the proposal.
>
> On Fri, Jun 14, 2019 at 7:53 PM Stas Berkov wrote:
>
>> guest271314, what is you point against `nameof` feature?
>>
>> If you don't like it - don't use it. Why prohibit this feature for
>> those who find it beneficial?
>>
>> I see `nameof` beneficial in following cases
>>
>> Case 1. Function guard.
>> ```
>> function func1(options) {
>> ...
>>if (options.userName == undefined) {
>>throw new ParamNullError(nameof options.userName); //
>> `ParamNullError` is a custom error, derived from `Error`, composes
>> error message like "Parameter cannot be null: userName".
>> // `Object.keys({options.userName})[0]` will not work here
>>}
>> }
>> ```
>>
>> Case 2. Accessing property extended info
>> Those ES functions that accept field name as string.
>> e.g.
>> ```
>> const descriptor1 = Object.getOwnPropertyDescriptor(object1, 'property1');
>> ```
>> vs
>> ```
>> const descriptor1 = Object.getOwnPropertyDescriptor(object1, nameof
>> object1.property1);
>> // `Object.keys({options1.property1})[0]` will not work here
>> ```
>> 2nd variant (proposed) has more chances not to be broken during
>> refactoring (robustness).
>>
>> It would make devs who use IDE more productive and make their life
>> easier. Why not give them such possiblity and make them happy?
>>
> ___
> es-discuss mailing list
> es-discuss@mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
RE: Re: What do you think about a C# 6 like nameof() expression for
> Interesting. ```y``` would be able to be evaluated before ```y``` is defined? I very explicitly stated that `nameof y` would *not* evaluate its operand. Evaluation of `nameof` would merely result in a string containing the name of the binding referenced by the operand. From: es-discuss On Behalf Of guest271314 Sent: Friday, June 14, 2019 12:09 PM To: Stas Berkov Cc: es-discuss@mozilla.org Subject: Re: Re: What do you think about a C# 6 like nameof() expression for > A module namespace isn’t an instance of Module, it’s a module namespace spec > object. If it has a name member, that is because the module you imported has > an exported binding called name. But what kind of thing it is isn’t what > matters. If ```Object.getOwnPropertyDescriptors(ns)``` is used within
Re: Re: What do you think about a C# 6 like nameof() expression for
Am neither for nor against the proposal. Do not entertain "like"s or
"dislike"s in any field of endeavor. Am certainly not in a position to
prohibit anything relevant JavaScript. Do what thou wilt shall be the whole
of the Law.
Have yet to view a case where code will be "broken" by ```nameof``` not
being a JavaScript feature. "robustness", as already mentioned, is a
subjective adjective that is not capable of being objectively evaluated as
to code itself. That description is based on preference or choice.
In lieu of the proposal being specificed, use the posted code example of
```Object.keys()``` that "works".
```
function func1({userName = void 0} = {}) {
console.assert(userName !== undefined, [{userName}, 'property needs to be
defined'])
}
```
provides a direct indication that the property value is required to be
defined. Note that the example code posted thus far does not first check if
```options``` is passed at all, for which ```nameof``` will not provide any
asssitance.
Usually try to meet requirement by means already available in FOSS
browsers. Have no interest in TypeScript or using an IDE.
FWIW, have no objection to the proposal.
On Fri, Jun 14, 2019 at 7:53 PM Stas Berkov wrote:
> guest271314, what is you point against `nameof` feature?
>
> If you don't like it - don't use it. Why prohibit this feature for
> those who find it beneficial?
>
> I see `nameof` beneficial in following cases
>
> Case 1. Function guard.
> ```
> function func1(options) {
> ...
>if (options.userName == undefined) {
>throw new ParamNullError(nameof options.userName); //
> `ParamNullError` is a custom error, derived from `Error`, composes
> error message like "Parameter cannot be null: userName".
> // `Object.keys({options.userName})[0]` will not work here
>}
> }
> ```
>
> Case 2. Accessing property extended info
> Those ES functions that accept field name as string.
> e.g.
> ```
> const descriptor1 = Object.getOwnPropertyDescriptor(object1, 'property1');
> ```
> vs
> ```
> const descriptor1 = Object.getOwnPropertyDescriptor(object1, nameof
> object1.property1);
> // `Object.keys({options1.property1})[0]` will not work here
> ```
> 2nd variant (proposed) has more chances not to be broken during
> refactoring (robustness).
>
> It would make devs who use IDE more productive and make their life
> easier. Why not give them such possiblity and make them happy?
>
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
Re: Re: What do you think about a C# 6 like nameof() expression for
guest271314, what is you point against `nameof` feature?
If you don't like it - don't use it. Why prohibit this feature for
those who find it beneficial?
I see `nameof` beneficial in following cases
Case 1. Function guard.
```
function func1(options) {
...
if (options.userName == undefined) {
throw new ParamNullError(nameof options.userName); //
`ParamNullError` is a custom error, derived from `Error`, composes
error message like "Parameter cannot be null: userName".
// `Object.keys({options.userName})[0]` will not work here
}
}
```
Case 2. Accessing property extended info
Those ES functions that accept field name as string.
e.g.
```
const descriptor1 = Object.getOwnPropertyDescriptor(object1, 'property1');
```
vs
```
const descriptor1 = Object.getOwnPropertyDescriptor(object1, nameof
object1.property1);
// `Object.keys({options1.property1})[0]` will not work here
```
2nd variant (proposed) has more chances not to be broken during
refactoring (robustness).
It would make devs who use IDE more productive and make their life
easier. Why not give them such possiblity and make them happy?
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
Re: Re: What do you think about a C# 6 like nameof() expression for
> A module namespace isn’t an instance of Module, it’s a module namespace spec object. If it has a name member, that is because the module you imported has an exported binding called name. But what kind of thing it is isn’t what matters. If ```Object.getOwnPropertyDescriptors(ns)``` is used within
RE: Re: What do you think about a C# 6 like nameof() expression for
Since `nameof` does not actually evaluate anything, the following would be
legal:
```
const x = nameof y; // "y"
const y = 1;
```
However, the shorthand property name workaround is not legal due to TDZ:
```
const x = Object.keys({y})[0]; // error due to TDZ
const y = 1;
```
With the shortand property name workaround you also run into the added runtime
overhead of:
* Constructing an object (`{y}`)
* Looking up a property (`Object.keys`)
* Calling a function (`Object.keys`)
* Allocating an array
* Indexing into the array
Whereas `nameof` has *no* runtime overhead, because it would be handled during
static semantics.
From: es-discuss On Behalf Of guest271314
Sent: Friday, June 14, 2019 11:17 AM
To: Stas Berkov
Cc: es-discuss@mozilla.org
Subject: Re: Re: What do you think about a C# 6 like nameof() expression for
Terms such as "more robust", "Less fragile." , "Less mess." are subjective.
"Fragile" how? What is meant by "mess"?
If the proposal is that ```nameof``` is briefer than using shorthand property
names or computed property names to get an identifier as a string, then
```nameof``` would be less code.
> You can rename field/property without fear you break something (using IDE
> refactoring tools).
The use case appears to be within the context of an IDE?
For users that roll their own code by hand at a text editor and do not use an
IDE for composing code (or relying on an IDE for logging errors), am not able
to discern how ```nameof``` is different than using
```Object.getOwnPropertyDescriptors(other).name.value``` or
```Object.keys({userName})[0]```. The actual code will need to be tested in
different browsers anyway before deployment to get the actual results.
If a user has decided they _have_ to use some form of a dynamic "IDE" to
compose code and log errors - while they are writing the code, they can open
DevTools at Chromium or Chrome then select ```Sources``` => ```Snippets``` =>
```New snippet```, where
```
const n = 123;
const n = 456;
```
will highlight the line where the error occurs - during writing the code - the
as a red circle with a transparent "x" in the middle
```Uncaught SyntaxError: Identifier 'n' has already been declared
To run the code press ```ctrl+enter```.
On Fri, Jun 14, 2019 at 5:48 PM Stas Berkov
mailto:stas.ber...@gmail.com>> wrote:
Less fragile. Less mess. You can rename field/property without fear you break
something (using IDE refactoring tools).
With high probablity you will break something when you refactor and have fields
hardcoded as strings.
Someone can object that you can rename strings as well.
Issue here that you can ocassionally change non-related strings that should not
be changed even they match or have matching substring.
On Fri, Jun 14, 2019 at 9:38 PM guest271314
mailto:guest271...@gmail.com>> wrote:
Is Case 1 equivalent to a briefer version of
```
if (userName == undefined) {
throw new Error(`Argument cannot be null:
${Object.keys({userName})[0]}`);
}
```
?
If not, how is ```nameof``` different?
What is the difference between the use of
```message.hasOwnProperty(property)``` and ```nameof msg.expiration_utc_time```?
> You get more robust code.
How is "robust" objectively determined?
On Fri, Jun 14, 2019 at 5:21 PM Stas Berkov
mailto:stas.ber...@gmail.com>> wrote:
ES can befit from `nameof` feature the same way as TS. There is no TS specific
in it.
It was ask to introduce in TS as a workaround since TS is considered as
extention of ES.
Case 1. Function guard.
```
function func1(param1, param2, param3, userName, param4, param5) {
if (userName == undefined) {
throw new ArgumentNullError(nameof userName); // `ArgumentNullError` is
a custom error, derived from `Error`, composes error message like "Argument
cannot be null: userName".
}
}
```
Case 2. Access extended information an object property.
Assume a function
```
function protoPropertyIsSet(message, property) {
return message != null && message.hasOwnProperty(property);
}
```
Then in code you use it as `if (protoPropertyIsSet(msg, "expiration_utc_time"))
{... }`.
Having `nameof` would allow you to do that `if (protoPropertyIsSet(msg, nameof
msg.expiration_utc_time)) {... }`.
You get more robust code.
On Fri, Jun 14, 2019 at 5:46 PM Augusto Moura
mailto:augusto.borg...@gmail.com>> wrote:
Can you list the benefits of having this operators? Maybe with example use cases
If I understand it correctly, the operator fits better in compiled
(and typed) languages, most of the use cases don't apply to dynamic
Javascript
The only legit use case I can think of is helping refactor tools to
rename properties (but even mismatch errors between strings and
properties names can be caught in compile time using modern
Typescript)
Em sex, 14 de jun de 2019 às 10:05, Stas Berkov
mailto:stas.ber...@gmail.com>> escreveu:
>
> Can we revisit this issue?
>
>
> In C# there is `nameof`, in Swift you can do the same by
RE: Re: What do you think about a C# 6 like nameof() expression for
A module namespace isn’t an instance of `Module`, it’s a module namespace spec
object. If it has a `name` member, that is because the module you imported has
an exported binding called `name`. But what kind of thing it is isn’t what
matters.
`nameof` just returns a string representation of the static symbolic name of
its operand. `nameof` would be used at runtime (i.e. during code execution),
but provides the ability for advanced editors to include it in a “rename”
refactoring.
The operand merely needs to be an identifier that exists within the current
lexical scope. `nameof` would not observe TDZ and would not evaluate any
expression. The ECMAScript static semantics would merely: 1) check that the
identifier provided to `nameof` is the name of something in the current lexical
scope, and 2) replace the expression with a string literal representing the
name.
If `nameof foo.bar` were allowed `nameof` would not actually evaluate
`foo.bar`, but merely result in `”bar”`. `nameof` does not evaluate anything,
it is merely a syntactic transformation by the runtime that becomes a string.
Ron
From: guest271314
Sent: Friday, June 14, 2019 10:07 AM
To: Ron Buckton
Cc: es-discuss@mozilla.org
Subject: Re: Re: What do you think about a C# 6 like nameof() expression for
Not following the module example. Would not ```ns``` be an instance of
```Module``` where ```* as ns``` is used?
For the ```class``` example would ```nameof``` be equivalent to
```Object.getOwnPropertyDescriptors(other).name.value```?
It's not that a language like TypeScript would need this, but rather that users
of an editor like VS Code or WebStorm that have a JavaScript language service
would benefit from it.
Is the primary use case a non-simple text editor; e.g., _not_ gedit (GUI) or
pico or nano (CLI), where the user is depending on the program
for diagnostics (logging and errors)
within a text editor _before_ actually running the code in a given environment
- not to log errors during code execution?
On Fri, Jun 14, 2019 at 4:29 PM Ron Buckton
mailto:ron.buck...@microsoft.com>> wrote:
The 'nameof' operator provides the string name of a static symbol (in
compiler/linker terms, not an ECMAScript 'Symbol'). This is often useful for
diagnostics (logging and errors), and gives developers a way to reduce
repetition. It is also extremely helpful in editors that support symbolic
"rename" refactoring.
While ES functions have a 'name' property, one of the main use cases is to get
a string representation of the name of a thing that isn't itself reified as an
object, such as a variable, parameter, or module namespace:
```
import * as ns from "foo";
nameof ns; // "ns"
let fn = function g() {};
fn.name;
// "g"
nameof fn; // "fn"
```
Here is an example of two common use cases:
```
class C {
compare(other) {
if (!(other instanceof C)) {
throw new TypeError(`Invalid argument: ${nameof other} `);
}
set prop(value) {
this._prop = value;
this.emit("propertychanged", nameof prop);
}
}
```
It's not that a language like TypeScript would need this, but rather that users
of an editor like VS Code or WebStorm that have a JavaScript language service
would benefit from it.
Ron
From: es-discuss
mailto:es-discuss-boun...@mozilla.org>> on
behalf of guest271314 mailto:guest271...@gmail.com>>
Sent: Friday, June 14, 2019 9:05:55 AM
To: Stas Berkov
Cc: es-discuss@mozilla.org
Subject: Re: Re: What do you think about a C# 6 like nameof() expression for
Have not tried TypeScript. What are the use cases for JavaScript where
TypeScript is not used? Does ```nameof()``` check if an object has a specific
property name defined (```"MutationObserver" in window```;
```window.MutationObserver```; ```"document" in globalThis```)?
On Fri, Jun 14, 2019 at 1:05 PM Stas Berkov
mailto:stas.ber...@gmail.com>> wrote:
Can we revisit this issue?
In C# there is `nameof`, in Swift you can do the same by calling
```
let keyPath = \Person.mother.firstName
NSPredicate(format: "%K == %@", keyPath, "Andrew")
```
Let's introduce `nameof` in ES, please.
Devs from TypeScript don't want to introduce this feature in TypeScript unless
it is available in ES ( https://github.com/microsoft/TypeScript/issues/1579 )
This feature is eagarly being asked by TypeScript community.
I understand there are couple issues related to `nameof` feature in ES. They
are: minification and what to do if user already has `nameof` function.
Minification.
1. If your code to be minimized be prepared that variable names will also
change.
2. (just a possibility) Minimizer can have option to replace `nameof(someVar)`
with result of `nameof`
Re: Re: What do you think about a C# 6 like nameof() expression for
Terms such as "more robust", "Less fragile." , "Less mess." are subjective.
"Fragile" how? What is meant by "mess"?
If the proposal is that ```nameof``` is briefer than using shorthand
property names or computed property names to get an identifier as a string,
then ```nameof``` would be less code.
> You can rename field/property without fear you break something (using IDE
refactoring tools).
The use case appears to be within the context of an IDE?
For users that roll their own code by hand at a text editor and do not use
an IDE for composing code (or relying on an IDE for logging errors), am not
able to discern how ```nameof``` is different than using
```Object.getOwnPropertyDescriptors(other).name.value``` or
```Object.keys({userName})[0]```. The actual code will need to be tested in
different browsers anyway before deployment to get the actual results.
If a user has decided they _have_ to use some form of a dynamic "IDE" to
compose code and log errors - while they are writing the code, they can
open DevTools at Chromium or Chrome then select ```Sources``` =>
```Snippets``` => ```New snippet```, where
```
const n = 123;
const n = 456;
```
will highlight the line where the error occurs - during writing the code -
the as a red circle with a transparent "x" in the middle
```Uncaught SyntaxError: Identifier 'n' has already been declared
To run the code press ```ctrl+enter```.
On Fri, Jun 14, 2019 at 5:48 PM Stas Berkov wrote:
> Less fragile. Less mess. You can rename field/property without fear you
> break something (using IDE refactoring tools).
> With high probablity you will break something when you refactor and have
> fields hardcoded as strings.
> Someone can object that you can rename strings as well.
> Issue here that you can ocassionally change non-related strings that
> should not be changed even they match or have matching substring.
>
> On Fri, Jun 14, 2019 at 9:38 PM guest271314 wrote:
>
>> Is Case 1 equivalent to a briefer version of
>>
>> ```
>>if (userName == undefined) {
>>throw new Error(`Argument cannot be null:
>> ${Object.keys({userName})[0]}`);
>>}
>> ```
>>
>> ?
>>
>> If not, how is ```nameof``` different?
>>
>> What is the difference between the use of
>> ```message.hasOwnProperty(property)```
>> and ```nameof msg.expiration_utc_time```?
>>
>> > You get more robust code.
>>
>> How is "robust" objectively determined?
>>
>>
>>
>>
>> On Fri, Jun 14, 2019 at 5:21 PM Stas Berkov
>> wrote:
>>
>>> ES can befit from `nameof` feature the same way as TS. There is no TS
>>> specific in it.
>>> It was ask to introduce in TS as a workaround since TS is considered as
>>> extention of ES.
>>>
>>> Case 1. Function guard.
>>> ```
>>> function func1(param1, param2, param3, userName, param4, param5) {
>>>if (userName == undefined) {
>>>throw new ArgumentNullError(nameof userName); //
>>> `ArgumentNullError` is a custom error, derived from `Error`, composes error
>>> message like "Argument cannot be null: userName".
>>>}
>>> }
>>> ```
>>>
>>> Case 2. Access extended information an object property.
>>> Assume a function
>>> ```
>>> function protoPropertyIsSet(message, property) {
>>> return message != null && message.hasOwnProperty(property);
>>> }
>>> ```
>>> Then in code you use it as `if (protoPropertyIsSet(msg,
>>> "expiration_utc_time")) {... }`.
>>> Having `nameof` would allow you to do that `if (protoPropertyIsSet(msg,
>>> nameof msg.expiration_utc_time)) {... }`.
>>> You get more robust code.
>>>
>>> On Fri, Jun 14, 2019 at 5:46 PM Augusto Moura
>>> wrote:
>>>
Can you list the benefits of having this operators? Maybe with example
use cases
If I understand it correctly, the operator fits better in compiled
(and typed) languages, most of the use cases don't apply to dynamic
Javascript
The only legit use case I can think of is helping refactor tools to
rename properties (but even mismatch errors between strings and
properties names can be caught in compile time using modern
Typescript)
Em sex, 14 de jun de 2019 às 10:05, Stas Berkov
escreveu:
>
> Can we revisit this issue?
>
>
> In C# there is `nameof`, in Swift you can do the same by calling
>
> ```
>
> let keyPath = \Person.mother.firstName
>
> NSPredicate(format: "%K == %@", keyPath, "Andrew")
>
> ```
>
> Let's introduce `nameof` in ES, please.
>
>
> Devs from TypeScript don't want to introduce this feature in
TypeScript unless it is available in ES (
https://github.com/microsoft/TypeScript/issues/1579 )
>
> This feature is eagarly being asked by TypeScript community.
>
>
> I understand there are couple issues related to `nameof` feature in
ES. They are: minification and what to do if user already has `nameof`
function.
>
>
> Minification.
>
> 1. If your code to be
Re: Re: What do you think about a C# 6 like nameof() expression for
> Is Case 1 equivalent to a briefer version of
> ```
if (userName == undefined) {
throw new Error(`Argument cannot be null:
${Object.keys({userName})[0]}`);
}
```
Less readable but in this simple case might work.
What if we do the following:
Case 1. Function guard.
```
function func1(options) {
...
if (options.userName == undefined) {
throw new ParamNullError(nameof options.userName); //
`ParamNullError` is a custom error, derived from `Error`, composes error
message like "Argument cannot be null: userName".
}
}
```
Case 2. Accessing property extended info
e.g.
```
const descriptor1 = Object.getOwnPropertyDescriptor(object1, 'property1');
```
vs
```
const descriptor1 = Object.getOwnPropertyDescriptor(object1, nameof
object1.property1);
```
2nd variant (proposed) has more chances not to be broken during refactoring
(robustness).
On Fri, Jun 14, 2019 at 9:48 PM Stas Berkov wrote:
> Less fragile. Less mess. You can rename field/property without fear you
> break something (using IDE refactoring tools).
> With high probablity you will break something when you refactor and have
> fields hardcoded as strings.
> Someone can object that you can rename strings as well.
> Issue here that you can ocassionally change non-related strings that
> should not be changed even they match or have matching substring.
>
> On Fri, Jun 14, 2019 at 9:38 PM guest271314 wrote:
>
>> Is Case 1 equivalent to a briefer version of
>>
>> ```
>>if (userName == undefined) {
>>throw new Error(`Argument cannot be null:
>> ${Object.keys({userName})[0]}`);
>>}
>> ```
>>
>> ?
>>
>> If not, how is ```nameof``` different?
>>
>> What is the difference between the use of
>> ```message.hasOwnProperty(property)```
>> and ```nameof msg.expiration_utc_time```?
>>
>> > You get more robust code.
>>
>> How is "robust" objectively determined?
>>
>>
>>
>>
>> On Fri, Jun 14, 2019 at 5:21 PM Stas Berkov
>> wrote:
>>
>>> ES can befit from `nameof` feature the same way as TS. There is no TS
>>> specific in it.
>>> It was ask to introduce in TS as a workaround since TS is considered as
>>> extention of ES.
>>>
>>> Case 1. Function guard.
>>> ```
>>> function func1(param1, param2, param3, userName, param4, param5) {
>>>if (userName == undefined) {
>>>throw new ArgumentNullError(nameof userName); //
>>> `ArgumentNullError` is a custom error, derived from `Error`, composes error
>>> message like "Argument cannot be null: userName".
>>>}
>>> }
>>> ```
>>>
>>> Case 2. Access extended information an object property.
>>> Assume a function
>>> ```
>>> function protoPropertyIsSet(message, property) {
>>> return message != null && message.hasOwnProperty(property);
>>> }
>>> ```
>>> Then in code you use it as `if (protoPropertyIsSet(msg,
>>> "expiration_utc_time")) {... }`.
>>> Having `nameof` would allow you to do that `if (protoPropertyIsSet(msg,
>>> nameof msg.expiration_utc_time)) {... }`.
>>> You get more robust code.
>>>
>>> On Fri, Jun 14, 2019 at 5:46 PM Augusto Moura
>>> wrote:
>>>
Can you list the benefits of having this operators? Maybe with example
use cases
If I understand it correctly, the operator fits better in compiled
(and typed) languages, most of the use cases don't apply to dynamic
Javascript
The only legit use case I can think of is helping refactor tools to
rename properties (but even mismatch errors between strings and
properties names can be caught in compile time using modern
Typescript)
Em sex, 14 de jun de 2019 às 10:05, Stas Berkov
escreveu:
>
> Can we revisit this issue?
>
>
> In C# there is `nameof`, in Swift you can do the same by calling
>
> ```
>
> let keyPath = \Person.mother.firstName
>
> NSPredicate(format: "%K == %@", keyPath, "Andrew")
>
> ```
>
> Let's introduce `nameof` in ES, please.
>
>
> Devs from TypeScript don't want to introduce this feature in
TypeScript unless it is available in ES (
https://github.com/microsoft/TypeScript/issues/1579 )
>
> This feature is eagarly being asked by TypeScript community.
>
>
> I understand there are couple issues related to `nameof` feature in
ES. They are: minification and what to do if user already has `nameof`
function.
>
>
> Minification.
>
> 1. If your code to be minimized be prepared that variable names will
also change.
>
> 2. (just a possibility) Minimizer can have option to replace
`nameof(someVar)` with result of `nameof` function.
>
>
>
> What if user already has `nameof` function.
>
> 1. To maintain status quo we can user `nameof` function having
priority over newly introduced language feature.
>
> 2. OR we can use `typeof` syntax, e.g. `nameof msg.userName` (//
returns "userName" string)
>
>
Re: Re: What do you think about a C# 6 like nameof() expression for
Less fragile. Less mess. You can rename field/property without fear you
break something (using IDE refactoring tools).
With high probablity you will break something when you refactor and have
fields hardcoded as strings.
Someone can object that you can rename strings as well.
Issue here that you can ocassionally change non-related strings that should
not be changed even they match or have matching substring.
On Fri, Jun 14, 2019 at 9:38 PM guest271314 wrote:
> Is Case 1 equivalent to a briefer version of
>
> ```
>if (userName == undefined) {
>throw new Error(`Argument cannot be null:
> ${Object.keys({userName})[0]}`);
>}
> ```
>
> ?
>
> If not, how is ```nameof``` different?
>
> What is the difference between the use of
> ```message.hasOwnProperty(property)```
> and ```nameof msg.expiration_utc_time```?
>
> > You get more robust code.
>
> How is "robust" objectively determined?
>
>
>
>
> On Fri, Jun 14, 2019 at 5:21 PM Stas Berkov wrote:
>
>> ES can befit from `nameof` feature the same way as TS. There is no TS
>> specific in it.
>> It was ask to introduce in TS as a workaround since TS is considered as
>> extention of ES.
>>
>> Case 1. Function guard.
>> ```
>> function func1(param1, param2, param3, userName, param4, param5) {
>>if (userName == undefined) {
>>throw new ArgumentNullError(nameof userName); //
>> `ArgumentNullError` is a custom error, derived from `Error`, composes error
>> message like "Argument cannot be null: userName".
>>}
>> }
>> ```
>>
>> Case 2. Access extended information an object property.
>> Assume a function
>> ```
>> function protoPropertyIsSet(message, property) {
>> return message != null && message.hasOwnProperty(property);
>> }
>> ```
>> Then in code you use it as `if (protoPropertyIsSet(msg,
>> "expiration_utc_time")) {... }`.
>> Having `nameof` would allow you to do that `if (protoPropertyIsSet(msg,
>> nameof msg.expiration_utc_time)) {... }`.
>> You get more robust code.
>>
>> On Fri, Jun 14, 2019 at 5:46 PM Augusto Moura
>> wrote:
>>
>>> Can you list the benefits of having this operators? Maybe with example
>>> use cases
>>>
>>> If I understand it correctly, the operator fits better in compiled
>>> (and typed) languages, most of the use cases don't apply to dynamic
>>> Javascript
>>> The only legit use case I can think of is helping refactor tools to
>>> rename properties (but even mismatch errors between strings and
>>> properties names can be caught in compile time using modern
>>> Typescript)
>>>
>>> Em sex, 14 de jun de 2019 às 10:05, Stas Berkov
>>> escreveu:
>>> >
>>> > Can we revisit this issue?
>>> >
>>> >
>>> > In C# there is `nameof`, in Swift you can do the same by calling
>>> >
>>> > ```
>>> >
>>> > let keyPath = \Person.mother.firstName
>>> >
>>> > NSPredicate(format: "%K == %@", keyPath, "Andrew")
>>> >
>>> > ```
>>> >
>>> > Let's introduce `nameof` in ES, please.
>>> >
>>> >
>>> > Devs from TypeScript don't want to introduce this feature in
>>> TypeScript unless it is available in ES (
>>> https://github.com/microsoft/TypeScript/issues/1579 )
>>> >
>>> > This feature is eagarly being asked by TypeScript community.
>>> >
>>> >
>>> > I understand there are couple issues related to `nameof` feature in
>>> ES. They are: minification and what to do if user already has `nameof`
>>> function.
>>> >
>>> >
>>> > Minification.
>>> >
>>> > 1. If your code to be minimized be prepared that variable names will
>>> also change.
>>> >
>>> > 2. (just a possibility) Minimizer can have option to replace
>>> `nameof(someVar)` with result of `nameof` function.
>>> >
>>> >
>>> >
>>> > What if user already has `nameof` function.
>>> >
>>> > 1. To maintain status quo we can user `nameof` function having
>>> priority over newly introduced language feature.
>>> >
>>> > 2. OR we can use `typeof` syntax, e.g. `nameof msg.userName` (//
>>> returns "userName" string)
>>> >
>>> > ___
>>> > es-discuss mailing list
>>> > es-discuss@mozilla.org
>>> > https://mail.mozilla.org/listinfo/es-discuss
>>>
>>>
>>>
>>> --
>>> Atenciosamente,
>>>
>>> Augusto Borges de Moura
>>>
>> ___
>> es-discuss mailing list
>> es-discuss@mozilla.org
>> https://mail.mozilla.org/listinfo/es-discuss
>>
>
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
Re: Re: What do you think about a C# 6 like nameof() expression for
Is Case 1 equivalent to a briefer version of
```
if (userName == undefined) {
throw new Error(`Argument cannot be null:
${Object.keys({userName})[0]}`);
}
```
?
If not, how is ```nameof``` different?
What is the difference between the use of
```message.hasOwnProperty(property)```
and ```nameof msg.expiration_utc_time```?
> You get more robust code.
How is "robust" objectively determined?
On Fri, Jun 14, 2019 at 5:21 PM Stas Berkov wrote:
> ES can befit from `nameof` feature the same way as TS. There is no TS
> specific in it.
> It was ask to introduce in TS as a workaround since TS is considered as
> extention of ES.
>
> Case 1. Function guard.
> ```
> function func1(param1, param2, param3, userName, param4, param5) {
>if (userName == undefined) {
>throw new ArgumentNullError(nameof userName); //
> `ArgumentNullError` is a custom error, derived from `Error`, composes error
> message like "Argument cannot be null: userName".
>}
> }
> ```
>
> Case 2. Access extended information an object property.
> Assume a function
> ```
> function protoPropertyIsSet(message, property) {
> return message != null && message.hasOwnProperty(property);
> }
> ```
> Then in code you use it as `if (protoPropertyIsSet(msg,
> "expiration_utc_time")) {... }`.
> Having `nameof` would allow you to do that `if (protoPropertyIsSet(msg,
> nameof msg.expiration_utc_time)) {... }`.
> You get more robust code.
>
> On Fri, Jun 14, 2019 at 5:46 PM Augusto Moura
> wrote:
>
>> Can you list the benefits of having this operators? Maybe with example
>> use cases
>>
>> If I understand it correctly, the operator fits better in compiled
>> (and typed) languages, most of the use cases don't apply to dynamic
>> Javascript
>> The only legit use case I can think of is helping refactor tools to
>> rename properties (but even mismatch errors between strings and
>> properties names can be caught in compile time using modern
>> Typescript)
>>
>> Em sex, 14 de jun de 2019 às 10:05, Stas Berkov
>> escreveu:
>> >
>> > Can we revisit this issue?
>> >
>> >
>> > In C# there is `nameof`, in Swift you can do the same by calling
>> >
>> > ```
>> >
>> > let keyPath = \Person.mother.firstName
>> >
>> > NSPredicate(format: "%K == %@", keyPath, "Andrew")
>> >
>> > ```
>> >
>> > Let's introduce `nameof` in ES, please.
>> >
>> >
>> > Devs from TypeScript don't want to introduce this feature in TypeScript
>> unless it is available in ES (
>> https://github.com/microsoft/TypeScript/issues/1579 )
>> >
>> > This feature is eagarly being asked by TypeScript community.
>> >
>> >
>> > I understand there are couple issues related to `nameof` feature in ES.
>> They are: minification and what to do if user already has `nameof` function.
>> >
>> >
>> > Minification.
>> >
>> > 1. If your code to be minimized be prepared that variable names will
>> also change.
>> >
>> > 2. (just a possibility) Minimizer can have option to replace
>> `nameof(someVar)` with result of `nameof` function.
>> >
>> >
>> >
>> > What if user already has `nameof` function.
>> >
>> > 1. To maintain status quo we can user `nameof` function having priority
>> over newly introduced language feature.
>> >
>> > 2. OR we can use `typeof` syntax, e.g. `nameof msg.userName` (//
>> returns "userName" string)
>> >
>> > ___
>> > es-discuss mailing list
>> > es-discuss@mozilla.org
>> > https://mail.mozilla.org/listinfo/es-discuss
>>
>>
>>
>> --
>> Atenciosamente,
>>
>> Augusto Borges de Moura
>>
> ___
> es-discuss mailing list
> es-discuss@mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
Re: Re: What do you think about a C# 6 like nameof() expression for
ES can befit from `nameof` feature the same way as TS. There is no TS
specific in it.
It was ask to introduce in TS as a workaround since TS is considered as
extention of ES.
Case 1. Function guard.
```
function func1(param1, param2, param3, userName, param4, param5) {
if (userName == undefined) {
throw new ArgumentNullError(nameof userName); // `ArgumentNullError`
is a custom error, derived from `Error`, composes error message like
"Argument cannot be null: userName".
}
}
```
Case 2. Access extended information an object property.
Assume a function
```
function protoPropertyIsSet(message, property) {
return message != null && message.hasOwnProperty(property);
}
```
Then in code you use it as `if (protoPropertyIsSet(msg,
"expiration_utc_time")) {... }`.
Having `nameof` would allow you to do that `if (protoPropertyIsSet(msg,
nameof msg.expiration_utc_time)) {... }`.
You get more robust code.
On Fri, Jun 14, 2019 at 5:46 PM Augusto Moura
wrote:
> Can you list the benefits of having this operators? Maybe with example use
> cases
>
> If I understand it correctly, the operator fits better in compiled
> (and typed) languages, most of the use cases don't apply to dynamic
> Javascript
> The only legit use case I can think of is helping refactor tools to
> rename properties (but even mismatch errors between strings and
> properties names can be caught in compile time using modern
> Typescript)
>
> Em sex, 14 de jun de 2019 às 10:05, Stas Berkov
> escreveu:
> >
> > Can we revisit this issue?
> >
> >
> > In C# there is `nameof`, in Swift you can do the same by calling
> >
> > ```
> >
> > let keyPath = \Person.mother.firstName
> >
> > NSPredicate(format: "%K == %@", keyPath, "Andrew")
> >
> > ```
> >
> > Let's introduce `nameof` in ES, please.
> >
> >
> > Devs from TypeScript don't want to introduce this feature in TypeScript
> unless it is available in ES (
> https://github.com/microsoft/TypeScript/issues/1579 )
> >
> > This feature is eagarly being asked by TypeScript community.
> >
> >
> > I understand there are couple issues related to `nameof` feature in ES.
> They are: minification and what to do if user already has `nameof` function.
> >
> >
> > Minification.
> >
> > 1. If your code to be minimized be prepared that variable names will
> also change.
> >
> > 2. (just a possibility) Minimizer can have option to replace
> `nameof(someVar)` with result of `nameof` function.
> >
> >
> >
> > What if user already has `nameof` function.
> >
> > 1. To maintain status quo we can user `nameof` function having priority
> over newly introduced language feature.
> >
> > 2. OR we can use `typeof` syntax, e.g. `nameof msg.userName` (// returns
> "userName" string)
> >
> > ___
> > es-discuss mailing list
> > es-discuss@mozilla.org
> > https://mail.mozilla.org/listinfo/es-discuss
>
>
>
> --
> Atenciosamente,
>
> Augusto Borges de Moura
>
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
Re: Re: What do you think about a C# 6 like nameof() expression for
Not following the module example. Would not ```ns``` be an instance of
```Module``` where ```* as ns``` is used?
For the ```class``` example would ```nameof``` be equivalent to
```Object.getOwnPropertyDescriptors(other).name.value```?
It's not that a language like TypeScript would need this, but rather that
> users of an editor like VS Code or WebStorm that have a JavaScript language
> service would benefit from it.
Is the primary use case a non-simple text editor; e.g., _not_ gedit (GUI)
or pico or nano (CLI), where the user is depending on the program
for diagnostics (logging and errors)
within a text editor _before_ actually running the code in a given
environment - not to log errors during code execution?
On Fri, Jun 14, 2019 at 4:29 PM Ron Buckton
wrote:
> The 'nameof' operator provides the string name of a static symbol (in
> compiler/linker terms, not an ECMAScript 'Symbol'). This is often useful
> for diagnostics (logging and errors), and gives developers a way to reduce
> repetition. It is also extremely helpful in editors that support symbolic
> "rename" refactoring.
>
> While ES functions have a 'name' property, one of the main use cases is to
> get a string representation of the name of a thing that isn't itself
> reified as an object, such as a variable, parameter, or module namespace:
>
> ```
> import * as ns from "foo";
>
> nameof ns; // "ns"
>
> let fn = function g() {};
> fn.name; // "g"
> nameof fn; // "fn"
> ```
>
> Here is an example of two common use cases:
>
> ```
> class C {
> compare(other) {
> if (!(other instanceof C)) {
> throw new TypeError(`Invalid argument: ${nameof other} `);
> }
>
> set prop(value) {
> this._prop = value;
> this.emit("propertychanged", nameof prop);
> }
> }
> ```
>
> It's not that a language like TypeScript would need this, but rather that
> users of an editor like VS Code or WebStorm that have a JavaScript language
> service would benefit from it.
>
> Ron
> --
> *From:* es-discuss on behalf of
> guest271314
> *Sent:* Friday, June 14, 2019 9:05:55 AM
> *To:* Stas Berkov
> *Cc:* es-discuss@mozilla.org
> *Subject:* Re: Re: What do you think about a C# 6 like nameof()
> expression for
>
> Have not tried TypeScript. What are the use cases for JavaScript where
> TypeScript is not used? Does ```nameof()``` check if an object has a
> specific property name defined (```"MutationObserver" in window```;
> ```window.MutationObserver```; ```"document" in globalThis```)?
>
> On Fri, Jun 14, 2019 at 1:05 PM Stas Berkov wrote:
>
>> Can we revisit this issue?
>>
>>
>> In C# there is `nameof`, in Swift you can do the same by calling
>>
>> ```
>>
>> let keyPath = \Person.mother.firstName
>>
>> NSPredicate(format: "%K == %@", keyPath, "Andrew")
>>
>> ```
>>
>> Let's introduce `nameof` in ES, please.
>>
>>
>> Devs from TypeScript don't want to introduce this feature in TypeScript
>> unless it is available in ES (
>> https://github.com/microsoft/TypeScript/issues/1579
>>
>> )
>>
>> This feature is eagarly being asked by TypeScript community.
>>
>>
>> I understand there are couple issues related to `nameof` feature in ES.
>> They are: minification and what to do if user already has `nameof` function.
>>
>>
>> Minification.
>>
>> 1. If your code to be minimized be prepared that variable names will also
>> change.
>>
>> 2. (just a possibility) Minimizer can have option to replace
>> `nameof(someVar)` with result of `nameof` function.
>>
>>
>>
>> What if user already has `nameof` function.
>>
>> 1. To maintain status quo we can user `nameof` function having priority
>> over newly introduced language feature.
>>
>> 2. OR we can use `typeof` syntax, e.g. `nameof msg.userName` (// returns
>> "userName" string)
>> ___
>> es-discuss mailing list
>> es-discuss@mozilla.org
>> https://mail.mozilla.org/listinfo/es-discuss
>>
>>
>
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
Re: Re: What do you think about a C# 6 like nameof() expression for
The 'nameof' operator provides the string name of a static symbol (in
compiler/linker terms, not an ECMAScript 'Symbol'). This is often useful for
diagnostics (logging and errors), and gives developers a way to reduce
repetition. It is also extremely helpful in editors that support symbolic
"rename" refactoring.
While ES functions have a 'name' property, one of the main use cases is to get
a string representation of the name of a thing that isn't itself reified as an
object, such as a variable, parameter, or module namespace:
```
import * as ns from "foo";
nameof ns; // "ns"
let fn = function g() {};
fn.name; // "g"
nameof fn; // "fn"
```
Here is an example of two common use cases:
```
class C {
compare(other) {
if (!(other instanceof C)) {
throw new TypeError(`Invalid argument: ${nameof other} `);
}
set prop(value) {
this._prop = value;
this.emit("propertychanged", nameof prop);
}
}
```
It's not that a language like TypeScript would need this, but rather that users
of an editor like VS Code or WebStorm that have a JavaScript language service
would benefit from it.
Ron
From: es-discuss on behalf of guest271314
Sent: Friday, June 14, 2019 9:05:55 AM
To: Stas Berkov
Cc: es-discuss@mozilla.org
Subject: Re: Re: What do you think about a C# 6 like nameof() expression for
Have not tried TypeScript. What are the use cases for JavaScript where
TypeScript is not used? Does ```nameof()``` check if an object has a specific
property name defined (```"MutationObserver" in window```;
```window.MutationObserver```; ```"document" in globalThis```)?
On Fri, Jun 14, 2019 at 1:05 PM Stas Berkov
mailto:stas.ber...@gmail.com>> wrote:
Can we revisit this issue?
In C# there is `nameof`, in Swift you can do the same by calling
```
let keyPath = \Person.mother.firstName
NSPredicate(format: "%K == %@", keyPath, "Andrew")
```
Let's introduce `nameof` in ES, please.
Devs from TypeScript don't want to introduce this feature in TypeScript unless
it is available in ES (
https://github.com/microsoft/TypeScript/issues/1579
)
This feature is eagarly being asked by TypeScript community.
I understand there are couple issues related to `nameof` feature in ES. They
are: minification and what to do if user already has `nameof` function.
Minification.
1. If your code to be minimized be prepared that variable names will also
change.
2. (just a possibility) Minimizer can have option to replace `nameof(someVar)`
with result of `nameof` function.
What if user already has `nameof` function.
1. To maintain status quo we can user `nameof` function having priority over
newly introduced language feature.
2. OR we can use `typeof` syntax, e.g. `nameof msg.userName` (// returns
"userName" string)
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
___
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
Re: Re: What do you think about a C# 6 like nameof() expression for
Have not tried TypeScript. What are the use cases for JavaScript where TypeScript is not used? Does ```nameof()``` check if an object has a specific property name defined (```"MutationObserver" in window```; ```window.MutationObserver```; ```"document" in globalThis```)? On Fri, Jun 14, 2019 at 1:05 PM Stas Berkov wrote: > Can we revisit this issue? > > > In C# there is `nameof`, in Swift you can do the same by calling > > ``` > > let keyPath = \Person.mother.firstName > > NSPredicate(format: "%K == %@", keyPath, "Andrew") > > ``` > > Let's introduce `nameof` in ES, please. > > > Devs from TypeScript don't want to introduce this feature in TypeScript > unless it is available in ES ( > https://github.com/microsoft/TypeScript/issues/1579 ) > > This feature is eagarly being asked by TypeScript community. > > > I understand there are couple issues related to `nameof` feature in ES. > They are: minification and what to do if user already has `nameof` function. > > > Minification. > > 1. If your code to be minimized be prepared that variable names will also > change. > > 2. (just a possibility) Minimizer can have option to replace > `nameof(someVar)` with result of `nameof` function. > > > > What if user already has `nameof` function. > > 1. To maintain status quo we can user `nameof` function having priority > over newly introduced language feature. > > 2. OR we can use `typeof` syntax, e.g. `nameof msg.userName` (// returns > "userName" string) > ___ > es-discuss mailing list > es-discuss@mozilla.org > https://mail.mozilla.org/listinfo/es-discuss > ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
Re: Re: What do you think about a C# 6 like nameof() expression for
Can you list the benefits of having this operators? Maybe with example use cases If I understand it correctly, the operator fits better in compiled (and typed) languages, most of the use cases don't apply to dynamic Javascript The only legit use case I can think of is helping refactor tools to rename properties (but even mismatch errors between strings and properties names can be caught in compile time using modern Typescript) Em sex, 14 de jun de 2019 às 10:05, Stas Berkov escreveu: > > Can we revisit this issue? > > > In C# there is `nameof`, in Swift you can do the same by calling > > ``` > > let keyPath = \Person.mother.firstName > > NSPredicate(format: "%K == %@", keyPath, "Andrew") > > ``` > > Let's introduce `nameof` in ES, please. > > > Devs from TypeScript don't want to introduce this feature in TypeScript > unless it is available in ES ( > https://github.com/microsoft/TypeScript/issues/1579 ) > > This feature is eagarly being asked by TypeScript community. > > > I understand there are couple issues related to `nameof` feature in ES. They > are: minification and what to do if user already has `nameof` function. > > > Minification. > > 1. If your code to be minimized be prepared that variable names will also > change. > > 2. (just a possibility) Minimizer can have option to replace > `nameof(someVar)` with result of `nameof` function. > > > > What if user already has `nameof` function. > > 1. To maintain status quo we can user `nameof` function having priority over > newly introduced language feature. > > 2. OR we can use `typeof` syntax, e.g. `nameof msg.userName` (// returns > "userName" string) > > ___ > es-discuss mailing list > es-discuss@mozilla.org > https://mail.mozilla.org/listinfo/es-discuss -- Atenciosamente, Augusto Borges de Moura ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
Re: Re: What do you think about a C# 6 like nameof() expression for
Can we revisit this issue? In C# there is `nameof`, in Swift you can do the same by calling ``` let keyPath = \Person.mother.firstName NSPredicate(format: "%K == %@", keyPath, "Andrew") ``` Let's introduce `nameof` in ES, please. Devs from TypeScript don't want to introduce this feature in TypeScript unless it is available in ES ( https://github.com/microsoft/TypeScript/issues/1579 ) This feature is eagarly being asked by TypeScript community. I understand there are couple issues related to `nameof` feature in ES. They are: minification and what to do if user already has `nameof` function. Minification. 1. If your code to be minimized be prepared that variable names will also change. 2. (just a possibility) Minimizer can have option to replace `nameof(someVar)` with result of `nameof` function. What if user already has `nameof` function. 1. To maintain status quo we can user `nameof` function having priority over newly introduced language feature. 2. OR we can use `typeof` syntax, e.g. `nameof msg.userName` (// returns "userName" string) ___ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
