Re: [webkit-dev] the name "AtomicString"

[Maciej Stachowiak]

> On Dec 20, 2018, at 11:24 AM, Geoffrey Garen  wrote:
> 
 So hard to pronounce though! Why not UniqueString? It’s not quite as 
 explicit but close enough. 
>>> 
>>> Wouldn’t it be confusing to use UniqueString type for a string that is 
>>> *common* in order to save memory?
>> 
>> I would interpret it as UniqueString(foo) means “give me the unique copy of 
>> string foo”. You use a unique copy so you can use the same string in many 
>> places without wasting memory, or excess time on string compares. It’s used 
>> in many places, but there is only one. (Maybe we should call it 
>> HighlanderString? OK, not serious.)
> 
> By definition, any string that has been uniqued is unique.
> 
> So, maybe we like “unique” or maybe we don’t. But if we like “unique”, it’s 
> strictly better than “uniqued”.
> 
>>> Personally, I like the AtomString proposal as it is close to the naming we 
>>> are used to and addresses the issue raised (atomic has a different meaning 
>>> with threading).
>>> Also, I had never heard of interned strings before.
> 
> AtomicString has two features:
> 
> (1) You do comparison by pointer / object identity;
> 
> (2) You never allocate two objects for the same sequence of characters.
> 
> JavaScript symbols offer (1) but avoid (2):
> 
>   let a = Symbol(“The string of the past!”);
>   let b = Symbol(“The string of the past!”);
>   a == b; // false
>   a === b; // false
> 
> Today we call (1) “UniquedStringImpl” and (1) + (2) “AtomicStringImpl”.
> 
> If we rename (1) + (2) to “UniqueString” or “UniquedString”, we need a new 
> name for (1) alone.

It seems like (1) alone is not actually “uniqued". In the case of symbols at 
least, it's the opposite: the string deliberately kept distinct from all other 
strings of equal value, so pointer equality is used as a check for equality by 
pointer identity, rather than a shortcut for equality by value. 

From what I can tell, UniquedStringImpl exists mainly to be a base class for 
SymbolImpl and AtomicStringImpl. So you could imagine giving it a more verbose 
and explicit name, like PointerEqualityStringImpl. However, JSC seems to use 
UniquedStringImpl directly in a bunch of cases, I think to make it convenient 
for a property name to be either an AtomicString or a Symbol. Maybe a longer 
name for that case is ok?

Regards,
Maciej


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Re: [webkit-dev] the name "AtomicString"

[Geoffrey Garen]

>>> So hard to pronounce though! Why not UniqueString? It’s not quite as 
>>> explicit but close enough. 
>> 
>> Wouldn’t it be confusing to use UniqueString type for a string that is 
>> *common* in order to save memory?
> 
> I would interpret it as UniqueString(foo) means “give me the unique copy of 
> string foo”. You use a unique copy so you can use the same string in many 
> places without wasting memory, or excess time on string compares. It’s used 
> in many places, but there is only one. (Maybe we should call it 
> HighlanderString? OK, not serious.)

By definition, any string that has been uniqued is unique.

So, maybe we like “unique” or maybe we don’t. But if we like “unique”, it’s 
strictly better than “uniqued”.

>> Personally, I like the AtomString proposal as it is close to the naming we 
>> are used to and addresses the issue raised (atomic has a different meaning 
>> with threading).
>> Also, I had never heard of interned strings before.

AtomicString has two features:

(1) You do comparison by pointer / object identity;

(2) You never allocate two objects for the same sequence of characters.

JavaScript symbols offer (1) but avoid (2):

let a = Symbol(“The string of the past!”);
let b = Symbol(“The string of the past!”);
a == b; // false
a === b; // false

Today we call (1) “UniquedStringImpl” and (1) + (2) “AtomicStringImpl”.

If we rename (1) + (2) to “UniqueString” or “UniquedString”, we need a new name 
for (1) alone.

Geoff___
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Re: [webkit-dev] the name "AtomicString"

[Maciej Stachowiak]

> On Dec 19, 2018, at 9:41 PM, Chris Dumez  wrote:
> 
>> 
>> On Dec 19, 2018, at 9:17 PM, Maciej Stachowiak > > wrote:
>> 
>> 
>> 
>>> On Dec 19, 2018, at 8:06 PM, Ryosuke Niwa >> > wrote:
>>> 
>>> On Wed, Dec 19, 2018 at 1:13 PM Simon Fraser >> > wrote:
>>> > On Dec 19, 2018, at 12:33 PM, Michael Catanzaro >> > > wrote:
>>> > 
>>> > On Tue, Dec 18, 2018 at 9:31 PM, Darin Adler >> > > wrote:
>>> >> I’ve gotten used to the name AtomicString over the years, but I wouldn’t 
>>> >> strongly object to changing it if other programmers are often confused 
>>> >> by it’s similarity to the term “atomic operations”.
>>> > 
>>> > Well there were two other developers in the thread Ryosuke linked to who 
>>> > made the exact same mistake as me, so I do think the current name is 
>>> > problematic. A change wouldn't need to be drastic, though. I think 
>>> > suggestions from the old thread like "StringAtom" or "AtomString" would 
>>> > be unproblematic. The problem is the specific word "atomic" carries an 
>>> > expectation that the object be safe to access concurrently across threads 
>>> > without locks; I think that expectation doesn't exist if not for the "ic" 
>>> > at the end.
>>> > 
>>> > FWIW I've only ever heard the "interned string" terminology prior to now.
>>> 
>>> SingletonString?
>>> UniquedString?
>>> 
>>> I do like UniquedString. That conveys what AtomicString really is. 
>>> SingletonString isn't so great since AtomicString table is still per thread.
>> 
>> So hard to pronounce though! Why not UniqueString? It’s not quite as 
>> explicit but close enough. 
> 
> Wouldn’t it be confusing to use UniqueString type for a string that is 
> *common* in order to save memory?

I would interpret it as UniqueString(foo) means “give me the unique copy of 
string foo”. You use a unique copy so you can use the same string in many 
places without wasting memory, or excess time on string compares. It’s used in 
many places, but there is only one. (Maybe we should call it HighlanderString? 
OK, not serious.)

> 
> Personally, I like the AtomString proposal as it is close to the naming we 
> are used to and addresses the issue raised (atomic has a different meaning 
> with threading).
> Also, I had never heard of interned strings before.

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Re: [webkit-dev] the name "AtomicString"

[Chris Dumez]

> On Dec 19, 2018, at 9:41 PM, Chris Dumez  wrote:
> 
>> 
>> On Dec 19, 2018, at 9:17 PM, Maciej Stachowiak > > wrote:
>> 
>> 
>> 
>>> On Dec 19, 2018, at 8:06 PM, Ryosuke Niwa >> > wrote:
>>> 
>>> On Wed, Dec 19, 2018 at 1:13 PM Simon Fraser >> > wrote:
>>> > On Dec 19, 2018, at 12:33 PM, Michael Catanzaro >> > > wrote:
>>> > 
>>> > On Tue, Dec 18, 2018 at 9:31 PM, Darin Adler >> > > wrote:
>>> >> I’ve gotten used to the name AtomicString over the years, but I wouldn’t 
>>> >> strongly object to changing it if other programmers are often confused 
>>> >> by it’s similarity to the term “atomic operations”.
>>> > 
>>> > Well there were two other developers in the thread Ryosuke linked to who 
>>> > made the exact same mistake as me, so I do think the current name is 
>>> > problematic. A change wouldn't need to be drastic, though. I think 
>>> > suggestions from the old thread like "StringAtom" or "AtomString" would 
>>> > be unproblematic. The problem is the specific word "atomic" carries an 
>>> > expectation that the object be safe to access concurrently across threads 
>>> > without locks; I think that expectation doesn't exist if not for the "ic" 
>>> > at the end.
>>> > 
>>> > FWIW I've only ever heard the "interned string" terminology prior to now.
>>> 
>>> SingletonString?
>>> UniquedString?
>>> 
>>> I do like UniquedString. That conveys what AtomicString really is. 
>>> SingletonString isn't so great since AtomicString table is still per thread.
>> 
>> So hard to pronounce though! Why not UniqueString? It’s not quite as 
>> explicit but close enough. 
> 
> Wouldn’t it be confusing to use UniqueString type for a string that is 
> *common* in order to save memory?
> 
> Personally, I like the AtomString proposal as it is close to the naming we 
> are used to and addresses the issue raised (atomic has a different meaning 
> with threading).

Or I also like “AtomizedString”.

> Also, I had never heard of interned strings before.
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Re: [webkit-dev] the name "AtomicString"

[Chris Dumez]

> On Dec 19, 2018, at 9:17 PM, Maciej Stachowiak  wrote:
> 
> 
> 
>> On Dec 19, 2018, at 8:06 PM, Ryosuke Niwa > > wrote:
>> 
>> On Wed, Dec 19, 2018 at 1:13 PM Simon Fraser > > wrote:
>> > On Dec 19, 2018, at 12:33 PM, Michael Catanzaro > > > wrote:
>> > 
>> > On Tue, Dec 18, 2018 at 9:31 PM, Darin Adler > > > wrote:
>> >> I’ve gotten used to the name AtomicString over the years, but I wouldn’t 
>> >> strongly object to changing it if other programmers are often confused by 
>> >> it’s similarity to the term “atomic operations”.
>> > 
>> > Well there were two other developers in the thread Ryosuke linked to who 
>> > made the exact same mistake as me, so I do think the current name is 
>> > problematic. A change wouldn't need to be drastic, though. I think 
>> > suggestions from the old thread like "StringAtom" or "AtomString" would be 
>> > unproblematic. The problem is the specific word "atomic" carries an 
>> > expectation that the object be safe to access concurrently across threads 
>> > without locks; I think that expectation doesn't exist if not for the "ic" 
>> > at the end.
>> > 
>> > FWIW I've only ever heard the "interned string" terminology prior to now.
>> 
>> SingletonString?
>> UniquedString?
>> 
>> I do like UniquedString. That conveys what AtomicString really is. 
>> SingletonString isn't so great since AtomicString table is still per thread.
> 
> So hard to pronounce though! Why not UniqueString? It’s not quite as explicit 
> but close enough. 

Wouldn’t it be confusing to use UniqueString type for a string that is *common* 
in order to save memory?

Personally, I like the AtomString proposal as it is close to the naming we are 
used to and addresses the issue raised (atomic has a different meaning with 
threading).
Also, I had never heard of interned strings before.___
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Re: [webkit-dev] the name "AtomicString"

[Maciej Stachowiak]

> On Dec 19, 2018, at 8:06 PM, Ryosuke Niwa  wrote:
> 
> On Wed, Dec 19, 2018 at 1:13 PM Simon Fraser  > wrote:
> > On Dec 19, 2018, at 12:33 PM, Michael Catanzaro  > > wrote:
> > 
> > On Tue, Dec 18, 2018 at 9:31 PM, Darin Adler  > > wrote:
> >> I’ve gotten used to the name AtomicString over the years, but I wouldn’t 
> >> strongly object to changing it if other programmers are often confused by 
> >> it’s similarity to the term “atomic operations”.
> > 
> > Well there were two other developers in the thread Ryosuke linked to who 
> > made the exact same mistake as me, so I do think the current name is 
> > problematic. A change wouldn't need to be drastic, though. I think 
> > suggestions from the old thread like "StringAtom" or "AtomString" would be 
> > unproblematic. The problem is the specific word "atomic" carries an 
> > expectation that the object be safe to access concurrently across threads 
> > without locks; I think that expectation doesn't exist if not for the "ic" 
> > at the end.
> > 
> > FWIW I've only ever heard the "interned string" terminology prior to now.
> 
> SingletonString?
> UniquedString?
> 
> I do like UniquedString. That conveys what AtomicString really is. 
> SingletonString isn't so great since AtomicString table is still per thread.

So hard to pronounce though! Why not UniqueString? It’s not quite as explicit 
but close enough. 

Cheers,
Maciej

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Re: [webkit-dev] the name "AtomicString"

[Ryosuke Niwa]

On Wed, Dec 19, 2018 at 1:13 PM Simon Fraser  wrote:

> > On Dec 19, 2018, at 12:33 PM, Michael Catanzaro 
> wrote:
> >
> > On Tue, Dec 18, 2018 at 9:31 PM, Darin Adler  wrote:
> >> I’ve gotten used to the name AtomicString over the years, but I
> wouldn’t strongly object to changing it if other programmers are often
> confused by it’s similarity to the term “atomic operations”.
> >
> > Well there were two other developers in the thread Ryosuke linked to who
> made the exact same mistake as me, so I do think the current name is
> problematic. A change wouldn't need to be drastic, though. I think
> suggestions from the old thread like "StringAtom" or "AtomString" would be
> unproblematic. The problem is the specific word "atomic" carries an
> expectation that the object be safe to access concurrently across threads
> without locks; I think that expectation doesn't exist if not for the "ic"
> at the end.
> >
> > FWIW I've only ever heard the "interned string" terminology prior to now.
>
> SingletonString?
> UniquedString?
>

I do like UniquedString. That conveys what AtomicString really is.
SingletonString isn't so great since AtomicString table is still per thread.

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Re: [webkit-dev] the name "AtomicString"

[Darin Adler]

Seems to me we could fix the current problem by renaming from AtomicString to 
AtomString without causing any new problem.

— Darin
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Re: [webkit-dev] the name "AtomicString"

[Maciej Stachowiak]

> On Dec 19, 2018, at 12:33 PM, Michael Catanzaro  wrote:
> 
> On Tue, Dec 18, 2018 at 9:31 PM, Darin Adler  wrote:
>> I’ve gotten used to the name AtomicString over the years, but I wouldn’t 
>> strongly object to changing it if other programmers are often confused by 
>> it’s similarity to the term “atomic operations”.
> 
> Well there were two other developers in the thread Ryosuke linked to who made 
> the exact same mistake as me, so I do think the current name is problematic. 
> A change wouldn't need to be drastic, though. I think suggestions from the 
> old thread like "StringAtom" or "AtomString" would be unproblematic. The 
> problem is the specific word "atomic" carries an expectation that the object 
> be safe to access concurrently across threads without locks; I think that 
> expectation doesn't exist if not for the "ic" at the end.
> 
> FWIW I've only ever heard the "interned string" terminology prior to now.

“Interned string” is really obvious to people who have seen it but mysterious 
to those who have not. Unfortunately, I don’t think there is a term for this 
concept that most programmers will already know. So the best we can do is a 
term that is clearly something you need to look up and can’t be confused for 
something else. Another term of art name for this concept is Symbol. 
Unfortunately, search results for String, Atom and Atom String don’t give a 
helpful explanation, and Symbol could be confused with the JavaScript 
language’s notion of symbols. “Interned String” gives helpful search results, 
but is not the normal use of the terminology. Usually there is an operation 
called “intern”, or there might be reference to “string interning”, but it 
usually gives back just a plain string, or a type with a name like “atom” or 
“symbol”.

On balance, if we change, I’d lean towards Atom, since it is concise, obviously 
mysterious if you don’t know what it is, and understandable to at least some 
people who have seem that name for the concept. The only downside is that it’s 
not obvious from the name that it is a kind of string.

Regards,
Maciej

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Re: [webkit-dev] the name "AtomicString"

[Simon Fraser]

> On Dec 19, 2018, at 12:33 PM, Michael Catanzaro  wrote:
> 
> On Tue, Dec 18, 2018 at 9:31 PM, Darin Adler  wrote:
>> I’ve gotten used to the name AtomicString over the years, but I wouldn’t 
>> strongly object to changing it if other programmers are often confused by 
>> it’s similarity to the term “atomic operations”.
> 
> Well there were two other developers in the thread Ryosuke linked to who made 
> the exact same mistake as me, so I do think the current name is problematic. 
> A change wouldn't need to be drastic, though. I think suggestions from the 
> old thread like "StringAtom" or "AtomString" would be unproblematic. The 
> problem is the specific word "atomic" carries an expectation that the object 
> be safe to access concurrently across threads without locks; I think that 
> expectation doesn't exist if not for the "ic" at the end.
> 
> FWIW I've only ever heard the "interned string" terminology prior to now.

SingletonString?
UniquedString?

Simon

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Re: [webkit-dev] the name "AtomicString"

[Michael Catanzaro]

On Tue, Dec 18, 2018 at 9:31 PM, Darin Adler  wrote:
I’ve gotten used to the name AtomicString over the years, but I 
wouldn’t strongly object to changing it if other programmers are 
often confused by it’s similarity to the term “atomic 
operations”.


Well there were two other developers in the thread Ryosuke linked to 
who made the exact same mistake as me, so I do think the current name 
is problematic. A change wouldn't need to be drastic, though. I think 
suggestions from the old thread like "StringAtom" or "AtomString" would 
be unproblematic. The problem is the specific word "atomic" carries an 
expectation that the object be safe to access concurrently across 
threads without locks; I think that expectation doesn't exist if not 
for the "ic" at the end.


FWIW I've only ever heard the "interned string" terminology prior to 
now.


Michael

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Re: [webkit-dev] the name "AtomicString"

[Darin Adler]

The name “AtomicString” was inspired by the term of art, “atom”, traditionally 
used in at least some programming language implementations for what I see now 
is often called interned strings. You’ll see a mention of that term in the 
article https://en.wikipedia.org/wiki/String_interning in the context of ML 
along with some other terms used for this such as “symbol”.

I’ve gotten used to the name AtomicString over the years, but I wouldn’t 
strongly object to changing it if other programmers are often confused by it’s 
similarity to the term “atomic operations”.

A mild objection I have to the term “interned string” is that the term 
“interned” is not really a normal English word; I wasn’t familiar with that 
jargon when we named AtomicString and I am still not entirely thrilled with it. 
I think that specific term comes from the LISP intern function and is familiar 
to programmers largely because of its use in Java, .NET, and some other modern 
programming languages and libraries; I had encountered the technique many times 
over the years without ever hearing the word “interning” and don’t find the 
jargon entirely logical.

Some people might suggest using the term “flyweight string” instead 
https://en.wikipedia.org/wiki/Flyweight_pattern and I’m not sure which I’d 
prefer. Maybe there’s another obvious name?

Apparently in Delphi’s DWScript they called it “unified string” 
https://www.delphitools.info/2013/06/17/string-unification/ but in the article 
I cited they are chided for not calling it an interned string.

— Darin

PS: I do love loudly declaiming, “Atomic string, the string of tomorrow!” but I 
can get over it.
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