Re: Allows the use of part of the language keywords?
On Sunday, 28 August 2016 at 13:35:59 UTC, ketmar wrote:
it has nothing to do with compiler: parser skips comments when
peeking tokens. the only thing affected is simplistic syntax
highlighter that can't do proper lookup.
I have anyway never seen the necessity of the keyword "body"
anyway. I fact, I very much dislike it. You could write a function
Fn()
in {}
out() {}
{}
or even better (or at least what I would prefer):
Fn()
{}
in {}
out() {}
The parser will always take the block without preceeding keyword
as the body.
If you leave out "in" and "out", you also don't need the keyword
body. As soon as you add a contract, suddenly you have to add
that nasty "body". As I learned D this was confusing and I still
fail to see the benefit.
If you really feel the need to make explicit where the body
starts, you can add a comment:
Fn()
in
{
}
// body:
{
}
out()
{
}
Re: Allows the use of part of the language keywords?
On Sunday, 28 August 2016 at 13:26:26 UTC, Chris Wright wrote: On Sun, 28 Aug 2016 08:35:06 +, ketmar wrote: i have a perfect solution to this: don't write such code! It would reflect poorly on the compiler if it failed to compile something simply because you added a few comments. Especially since each C-style comment is likely its own token. A not-absurd usecase is a person condensing several functions into one, which might involve separately commenting out several function bodies. it has nothing to do with compiler: parser skips comments when peeking tokens. the only thing affected is simplistic syntax highlighter that can't do proper lookup.
Re: Allows the use of part of the language keywords?
On Sun, 28 Aug 2016 08:35:06 +, ketmar wrote: > i have a perfect solution to this: don't write such code! It would reflect poorly on the compiler if it failed to compile something simply because you added a few comments. Especially since each C-style comment is likely its own token. A not-absurd usecase is a person condensing several functions into one, which might involve separately commenting out several function bodies.
Re: Allows the use of part of the language keywords?
On Sunday, 28 August 2016 at 08:25:38 UTC, Basile B. wrote: to think that it can be detected with a simple lookup backward (or forward from the KW) is too simplistic. I'm not saying it'd necessarily be easy to distinguish keyword 'body' from identifier 'body' in the lexer, I'm just saying a 'look-behind' feature in a lexer would be trivial to implement.
Re: Allows the use of part of the language keywords?
On Sunday, 28 August 2016 at 08:25:38 UTC, Basile B. wrote:
On Sunday, 28 August 2016 at 08:07:27 UTC, Cauterite wrote:
On Sunday, 28 August 2016 at 04:32:46 UTC, Basile B. wrote:
You must keep track of the previous token, which is not
usually done in a scanner.
That sounds like a pretty trivial feature to me. There's no
way that's a legitimate obstacle.
Look at this, this is perfectly valid D code:
void main()
in {}
body /**/ #line 8
/**/
//
/+
/+
+/
+/
{}
to think that it can be detected with a simple lookup backward
(or forward from the KW) is too simplistic.
i have a perfect solution to this: don't write such code!
Re: Allows the use of part of the language keywords?
On Sunday, 28 August 2016 at 08:07:27 UTC, Cauterite wrote:
On Sunday, 28 August 2016 at 04:32:46 UTC, Basile B. wrote:
You must keep track of the previous token, which is not
usually done in a scanner.
That sounds like a pretty trivial feature to me. There's no way
that's a legitimate obstacle.
Look at this, this is perfectly valid D code:
void main()
in {}
body /**/ #line 8
/**/
//
/+
/+
+/
+/
{}
to think that it can be detected with a simple lookup backward
(or forward from the KW) is too simplistic.
Re: Allows the use of part of the language keywords?
On Sunday, 28 August 2016 at 04:32:46 UTC, Basile B. wrote: You must keep track of the previous token, which is not usually done in a scanner. That sounds like a pretty trivial feature to me. There's no way that's a legitimate obstacle.
Re: Allows the use of part of the language keywords?
On Sunday, 28 August 2016 at 04:32:46 UTC, Basile B. wrote: sorry, i cannot find where exactly i was asked about workaround for "stolen body" case. maybe it's 'cause i DIDN'T ASKED FOR WORKAROUND?
Re: Allows the use of part of the language keywords?
On Sun, 28 Aug 2016 04:32:46 +, Basile B. wrote: > Once again, the D style says to add a "_" after the keyword. If it's a > problem with the reflection it's also easy to check if an identifier > ends with "_" and then to remove it. Or use UDAs, which would be more general.
Re: Allows the use of part of the language keywords?
On 8/27/2016 7:35 PM, ketmar wrote: getting our precious `body` back will be invaluable! You are not of the body! https://www.youtube.com/watch?v=m48xii7ndcg
Re: Allows the use of part of the language keywords?
On Sunday, 28 August 2016 at 02:35:57 UTC, ketmar wrote:
On Saturday, 27 August 2016 at 20:45:56 UTC, Meta wrote:
On Saturday, 27 August 2016 at 19:21:52 UTC, Walter Bright
wrote:
It also:
1. mucks with the usability of syntax highlighting, which is
often based merely on tokens.
2. makes it potentially much more difficult to add features
to the language, which is often done by finding new uses for
the same keywords
3. is just plain confusing to the person learning the language
4. makes correctly diagnosing syntactic errors harder
There are a million words in the english language. Having a
handful of reserved words should not be a burden.
Could we at least make body a contextual keyword? It's a
commonly used word in many different areas.
YEAH! PLEASE-PLEASE-PLEASE-PLEASE! i did that, and it never
broke anything for years. as for syntax highlighters -- it's
not too hard to check if `body` is followed by `{`.
You must keep track of the previous token, which is not usually
done in a scanner.
Once again, the D style says to add a "_" after the keyword. If
it's a problem with the reflection it's also easy to check if an
identifier ends with "_" and then to remove it.
The examples of contextual keywords given by W.Bright in a
previous message are totally different from the "body" case
because in `extern(C)`, "C" is an identifier that becomes a
keyword in the context, while what you propose is that a keyword
becomes an identifier out of the context.
Re: Allows the use of part of the language keywords?
On Saturday, 27 August 2016 at 20:45:56 UTC, Meta wrote:
On Saturday, 27 August 2016 at 19:21:52 UTC, Walter Bright
wrote:
It also:
1. mucks with the usability of syntax highlighting, which is
often based merely on tokens.
2. makes it potentially much more difficult to add features to
the language, which is often done by finding new uses for the
same keywords
3. is just plain confusing to the person learning the language
4. makes correctly diagnosing syntactic errors harder
There are a million words in the english language. Having a
handful of reserved words should not be a burden.
Could we at least make body a contextual keyword? It's a
commonly used word in many different areas.
YEAH! PLEASE-PLEASE-PLEASE-PLEASE! i did that, and it never broke
anything for years. as for syntax highlighters -- it's not too
hard to check if `body` is followed by `{`. but getting our
precious `body` back will be invaluable!
Re: Allows the use of part of the language keywords?
On Saturday, 27 August 2016 at 19:21:52 UTC, Walter Bright wrote: It also: 1. mucks with the usability of syntax highlighting, which is often based merely on tokens. 2. makes it potentially much more difficult to add features to the language, which is often done by finding new uses for the same keywords 3. is just plain confusing to the person learning the language 4. makes correctly diagnosing syntactic errors harder There are a million words in the english language. Having a handful of reserved words should not be a burden. Could we at least make body a contextual keyword? It's a commonly used word in many different areas.
Re: Allows the use of part of the language keywords?
On 8/27/2016 6:36 AM, ZombineDev wrote: As Timon said, this won't make the grammar context dependent. Also, C# has the concept of contextual keywords. Such keywords have special meaning in certain contexts but are otherwise available for use as identifiers. C# also allows to use normal keywords as identifiers, but you have use the @for syntax to disambiguate (e.g. see http://rextester.com/JBOTC21251). From my experience of using C# the system is well designed and I have never seen problems in practice. I'm sure something similar can successfully be implemented for D. Though I would consider such enhancement with low priority. See https://msdn.microsoft.com/en-us/library/x53a06bb.aspx for more info. D has contextual keywords, too, and has had them since the beginning: extern (C) pragma (msg, ...) scope (exit) etc. Microsoft has tried to patent contextual keywords in C#, but I don't think they have a case.
Re: Allows the use of part of the language keywords?
On 8/27/2016 6:01 AM, Timon Gehr wrote: then not-entirely-trivial disambiguation has to be added to the parser. There's no ambiguity for the example in the OP though. It also: 1. mucks with the usability of syntax highlighting, which is often based merely on tokens. 2. makes it potentially much more difficult to add features to the language, which is often done by finding new uses for the same keywords 3. is just plain confusing to the person learning the language 4. makes correctly diagnosing syntactic errors harder There are a million words in the english language. Having a handful of reserved words should not be a burden.
Re: Allows the use of part of the language keywords?
On Friday, 26 August 2016 at 18:58:25 UTC, Jonathan M Davis wrote: On Friday, August 26, 2016 17:59:39 Cauterite via Digitalmars-d wrote: On Friday, 26 August 2016 at 14:16:27 UTC, Brian wrote: > package application.module.user.model; I get "Error: identifier expected following '.' instead of 'module'" So I'm not sure how that compiles for you. I think that he's looking for a language change that would allow you to use keywords in contexts where the keyword would not be valid. It's been suggested before, but it was rejected. If nothing else, it doesn't at all play nicely with how lexers and parsers normally work. It's _far_ cleaner if the compiler can treat a keyword as a keyword in all contexts that it's used. Not doing so makes the grammar context-dependent, whereas Walter has gone to great lengths to make it completely context-free. - Jonathan M Davis As Timon said, this won't make the grammar context dependent. Also, C# has the concept of contextual keywords. Such keywords have special meaning in certain contexts but are otherwise available for use as identifiers. C# also allows to use normal keywords as identifiers, but you have use the @for syntax to disambiguate (e.g. see http://rextester.com/JBOTC21251). From my experience of using C# the system is well designed and I have never seen problems in practice. I'm sure something similar can successfully be implemented for D. Though I would consider such enhancement with low priority. See https://msdn.microsoft.com/en-us/library/x53a06bb.aspx for more info.
Re: Allows the use of part of the language keywords?
On 26.08.2016 20:58, Jonathan M Davis via Digitalmars-d wrote: On Friday, August 26, 2016 17:59:39 Cauterite via Digitalmars-d wrote: On Friday, 26 August 2016 at 14:16:27 UTC, Brian wrote: package application.module.user.model; I get "Error: identifier expected following '.' instead of 'module'" So I'm not sure how that compiles for you. I think that he's looking for a language change that would allow you to use keywords in contexts where the keyword would not be valid. It's been suggested before, but it was rejected. If nothing else, it doesn't at all play nicely with how lexers and parsers normally work. It's _far_ cleaner if the compiler can treat a keyword as a keyword in all contexts that it's used. Not doing so makes the grammar context-dependent, whereas Walter has gone to great lengths to make it completely context-free. - Jonathan M Davis No, this would not introduce any context-dependence. https://en.wikipedia.org/wiki/Context-free_grammar That doesn't mean it is necessarily a great idea though. It increases ambiguity of the grammar, and hence, if you want to be able to parse things like auto enum = 3; enum +=2; then not-entirely-trivial disambiguation has to be added to the parser. There's no ambiguity for the example in the OP though.
Re: Allows the use of part of the language keywords?
On Friday, 26 August 2016 at 14:16:27 UTC, Brian wrote: PS: editor don't support markdown or bbcode?- - See this: http://dlang.org/blog/2016/06/10/core-team-update-vladimir-panteleev/
Re: Allows the use of part of the language keywords?
On Friday, 26 August 2016 at 14:16:27 UTC, Brian wrote:
Allows the use of part of the language keywords, example:
[code]
sturct module
{
// TODO
}
[code]
The D style as used in phobos says that you must add a "_" at the
end of the keyword that you wish to use as identifier.
When the problem happens because of linkage to an object or to a
static library there's the pragma(mangle):
https://dlang.org/spec/pragma.html#mangle
PS: editor don't support markdown or bbcode?- -
No, but people use several tricks to denote a code block: github
style block code, html tags etc. This times I use
°°
Re: Allows the use of part of the language keywords?
On 08/26/2016 11:58 AM, Jonathan M Davis via Digitalmars-d wrote: On Friday, August 26, 2016 17:59:39 Cauterite via Digitalmars-d wrote: On Friday, 26 August 2016 at 14:16:27 UTC, Brian wrote: package application.module.user.model; I get "Error: identifier expected following '.' instead of 'module'" So I'm not sure how that compiles for you. I think that he's looking for a language change that would allow you to use keywords in contexts where the keyword would not be valid. It's been suggested before, but it was rejected. If nothing else, it doesn't at all play nicely with how lexers and parsers normally work. It's _far_ cleaner if the compiler can treat a keyword as a keyword in all contexts that it's used. Not doing so makes the grammar context-dependent, whereas Walter has gone to great lengths to make it completely context-free. - Jonathan M Davis My understanding is completely different: The OP is looking for code highlight support on the forum. :D (Which actually is a newsgroup but I think the forum does support highlighting.) Ali
Re: Allows the use of part of the language keywords?
On Friday, August 26, 2016 17:59:39 Cauterite via Digitalmars-d wrote: > On Friday, 26 August 2016 at 14:16:27 UTC, Brian wrote: > > package application.module.user.model; > > I get "Error: identifier expected following '.' instead of > 'module'" > So I'm not sure how that compiles for you. I think that he's looking for a language change that would allow you to use keywords in contexts where the keyword would not be valid. It's been suggested before, but it was rejected. If nothing else, it doesn't at all play nicely with how lexers and parsers normally work. It's _far_ cleaner if the compiler can treat a keyword as a keyword in all contexts that it's used. Not doing so makes the grammar context-dependent, whereas Walter has gone to great lengths to make it completely context-free. - Jonathan M Davis
Re: Allows the use of part of the language keywords?
On Friday, 26 August 2016 at 14:16:27 UTC, Brian wrote: package application.module.user.model; I get "Error: identifier expected following '.' instead of 'module'" So I'm not sure how that compiles for you.
Allows the use of part of the language keywords?
Allows the use of part of the language keywords, example:
```D
package application.module.user.model;
class User
{
// TODO
}
```
[code]
sturct module
{
// TODO
}
[code]
PS: editor don't support markdown or bbcode?- -
