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digitalmars.D - Re: Is str ~ regex the root of all evil, or the leaf of all good?

reply bearophile <bearophileHUGS lycos.com> writes:
Daniel Keep:


 But it doesn't, and I can't see how it could given how confusing it
 would make things.



I think that using "in" into foreach() leads to less bugs, because it's easy to
not tell apart "," and a ";".
C# too uses in in such situation.
So far it was not accepted in D mostly because the compiler stages of D are
meant to be very separated.



 Besides which, we shouldn't be making judgements based on possible, not
planned for syntax changes at some unspecified point in the future. We have
enough trouble with deciding on things as it is. :P<



I agree that the situation isn't easy, and designing a language is hard. But
it's very useful to keep a long-range sight and avoid to step on our future
toes, when possible and when it's a cheap thing to do.

Bye,
bearophile
Feb 19 2009
next sibling parent reply Jarrett Billingsley <jarrett.billingsley gmail.com> writes:
On Thu, Feb 19, 2009 at 10:38 AM, bearophile <bearophileHUGS lycos.com> wrote:

 Daniel Keep:


 But it doesn't, and I can't see how it could given how confusing it
 would make things.



 I think that using "in" into foreach() leads to less bugs, because it's easy
to not tell apart "," and a ";".



The semicolon does not introduce bugs.  If you don't have a semicolon,
you get a simple parser error.  That is not a bug.  If you can't tell
; and , apart, get a better font.


 So far it was not accepted in D mostly because the compiler stages of D are
meant to be very separated.



That has little to nothing to do with it.  'in' in a foreach loop
header is unambiguous to parse.  I think it has much more to do with
the fact that semicolon works fine, is already present in mounds of D
code, and changing it to 'in' does not really benefit anyone except
you, since you're so goddamned attached to Python's syntax.  Use
Delight, ffs.

Also, "I think I don't like X" is not proper English.  Say "I don't
think I like X" or just "I don't like X" instead.
Feb 19 2009
next sibling parent reply bearophile <bearophileHUGS lycos.com> writes:
Jarrett Billingsley:

This is an old discussion, and maybe it will not lead to much.



If you don't have a semicolon, you get a simple parser error. That is not a
bug.<



Wikipedia agrees with me:

http://en.wikipedia.org/wiki/Software_bug

A software bug is an error, flaw, mistake, failure, or fault in a computer
program that prevents it from behaving as intended (e.g., producing an
incorrect or unexpected result).<



So a parser error is a bug too, despite the compiler will help you find it in a
moment.

I have written and debugged many times "mistakes" like:

foreach (a, b, iterable)
foreach (a; b; iterable)
foreach (a; b, iterable)

And probably I am not the only one :-)



If you can't tell ; and , apart, get a better font.<



I have already modified a good font to tell apart . and ; better when I program
D:

http://www.fantascienza.net/leonardo/ar/inconsolatag/inconsolata-g_font.zip

But having a language that is more bug-prone isn't good.



That has little to nothing to do with it.  'in' in a foreach loop header is
unambiguous to parse.<



You may have missed the discussion last time, when I think Walter has explained
what I have told you the problem about the compilation stages.



and changing it to 'in' does not really benefit anyone except you, since you're
so goddamned attached to Python's syntax.<



Thank you, I attach myself to things I think are good and well designed.
And Python isn't the only language that uses "in" with a "for-each" :-)



Use Delight, ffs.<



I don't know what "ffs" means, and I'm on Windows again now :-)



Also, "I think I don't like X" is not proper English.  Say "I don't think I
like X" or just "I don't like X" instead.<



Thank you very much, I'll try to remember that.

Bye,
bearophile
Feb 19 2009
next sibling parent reply Ary Borenszweig <ary esperanto.org.ar> writes:
bearophile wrote:

 Jarrett Billingsley:
 
 This is an old discussion, and maybe it will not lead to much.
 
 

 If you don't have a semicolon, you get a simple parser error. That is not a
bug.<



 Wikipedia agrees with me:
 
 http://en.wikipedia.org/wiki/Software_bug

 A software bug is an error, flaw, mistake, failure, or fault in a computer
program that prevents it from behaving as intended (e.g., producing an
incorrect or unexpected result).<



 So a parser error is a bug too, despite the compiler will help you find it in
a moment.
 
 I have written and debugged many times "mistakes" like:
 
 foreach (a, b, iterable)
 foreach (a; b; iterable)
 foreach (a; b, iterable)
 
 And probably I am not the only one :-)



Why would you do that?

Many times when writing C# loops I do foreach(x; ...) and then remember 
it's "in" in C#, because I'm used to writing ";" in Java. I prefer ";" 
because it's shorter and you write a lot of foreach loops in a program.

Maybe we should vote and see how many people make the mistake of 
confusing comma and semicolon in this case.


 
 

 If you can't tell ; and , apart, get a better font.<



 I have already modified a good font to tell apart . and ; better when I
program D:
 
 http://www.fantascienza.net/leonardo/ar/inconsolatag/inconsolata-g_font.zip
 
 But having a language that is more bug-prone isn't good.
 
 

 That has little to nothing to do with it.  'in' in a foreach loop header is
unambiguous to parse.<



 You may have missed the discussion last time, when I think Walter has
explained what I have told you the problem about the compilation stages.
 
 

 and changing it to 'in' does not really benefit anyone except you, since
you're so goddamned attached to Python's syntax.<



 Thank you, I attach myself to things I think are good and well designed.
 And Python isn't the only language that uses "in" with a "for-each" :-)
 
 

 Use Delight, ffs.<



 I don't know what "ffs" means, and I'm on Windows again now :-)
 
 

 Also, "I think I don't like X" is not proper English.  Say "I don't think I
like X" or just "I don't like X" instead.<






To Jarrett: why isn't it proper English? It makes sense to me.
Feb 19 2009
next sibling parent Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
Ary Borenszweig wrote:

 bearophile wrote:

 Jarrett Billingsley:

 This is an old discussion, and maybe it will not lead to much.



 If you don't have a semicolon, you get a simple parser error. That is 
 not a bug.<



 Wikipedia agrees with me:

 http://en.wikipedia.org/wiki/Software_bug

 A software bug is an error, flaw, mistake, failure, or fault in a 
 computer program that prevents it from behaving as intended (e.g., 
 producing an incorrect or unexpected result).<



 So a parser error is a bug too, despite the compiler will help you 
 find it in a moment.

 I have written and debugged many times "mistakes" like:

 foreach (a, b, iterable)
 foreach (a; b; iterable)
 foreach (a; b, iterable)

 And probably I am not the only one :-)



 Why would you do that?
 
 Many times when writing C# loops I do foreach(x; ...) and then remember 
 it's "in" in C#, because I'm used to writing ";" in Java. I prefer ";" 
 because it's shorter and you write a lot of foreach loops in a program.
 
 Maybe we should vote and see how many people make the mistake of 
 confusing comma and semicolon in this case.



Not confusing me. I'll note that if "in" were used, you could write:

foreach (a in b in c) {}

Now try explaining that one :o).


Andrei
Feb 19 2009
prev sibling parent Ary Borenszweig <ary esperanto.org.ar> writes:
Jarrett Billingsley escribió:

 On Thu, Feb 19, 2009 at 11:45 AM, Ary Borenszweig <ary esperanto.org.ar> wrote:
 

 Also, "I think I don't like X" is not proper English.  Say "I don't think
 I like X" or just "I don't like X" instead.<









 Andrei did a pretty good job of explaining indirectly why it's wrong ;)
 
 If you say "I think <something about myself>", it sounds very strange,
 because it sounds like you don't know what's going on in your own
 brain.  "I think X" often means "I'm not sure of X", so saying that
 you're unsure of what you do or don't like sounds odd indeed.



I think you're right.
Feb 19 2009
prev sibling parent Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
Jarrett Billingsley wrote:

 The point I'm making here is it doesn't matter whether it uses 'in' or
 ';' or ':' or '(%)#* ' to separate the loop indices from the container
 expression, because there will always be people who feel that another
 syntax is better or more natural.  Instead of arguing over minute
 details like this, let's worry about the important things, like the
 semantics of foreach loops.



I agree. One thing that ranges still don't address is binding multiple 
values to them:

foreach (a, b, c; range) statement

Steve promoted the idea that the code above is translated to:

{
     T1 a;
     T2 b;
     T3 c;
     auto __r = range;
     for (; !__r.empty; __r.next)
     {
         __r.head(a, b, c);
         statement
     }
}

It's a good idea, and I'd favor e.g. a discussion around it as opposed 
to one on whether ";" is the proper separator.

Oh, there was another wrinkle: if you have a container, how do you 
obtain a range from it? I suggested container.all, but then people said 
that's a step backwards from opApply. I think [] should be used for 
accessing all of a range. Something that is already a range simply 
returns "this" from opSlice(). So the code above with this other 
proposal tucked in becomes:

{
     T1 a;
     T2 b;
     T3 c;
     auto __r = range[];
     for (; !__r.empty; __r.next)
     {
         __r.head(a, b, c);
         statement
     }
}


Andrei
Feb 19 2009
prev sibling parent reply Derek Parnell <derek psych.ward> writes:
On Thu, 19 Feb 2009 10:45:44 -0500, Jarrett Billingsley wrote:


 Also, "I think I don't like X" is not proper English.  Say "I don't
 think I like X" or just "I don't like X" instead.



Of course its proper English.

"I think I don't like X" means that I'm undecided about whether or not I
like X but I probably do not like it.

"I don't think I like X" means that I *know* that I don't like X, there is
no uncertainty.


-- 
Derek Parnell
Melbourne, Australia
skype: derek.j.parnell
Feb 19 2009
next sibling parent Derek Parnell <derek psych.ward> writes:
On Thu, 19 Feb 2009 17:59:13 -0500, Jarrett Billingsley wrote:


 On Thu, Feb 19, 2009 at 4:06 PM, Derek Parnell <derek psych.ward> wrote:

 On Thu, 19 Feb 2009 10:45:44 -0500, Jarrett Billingsley wrote:


 Also, "I think I don't like X" is not proper English.  Say "I don't
 think I like X" or just "I don't like X" instead.



 Of course its proper English.

 "I think I don't like X" means that I'm undecided about whether or not I
 like X but I probably do not like it.

 "I don't think I like X" means that I *know* that I don't like X, there is
 no uncertainty.



 See, it's funny, because I would think "I don't think I like X" means
 that I'm undecided about whether or not I like X but I probably don't;
 and that "I don't like X" means that I know that I don't like it.  "I
 think I don't X" just sounds very unnatural to me.



Maybe is a difference between American English and Australian English?

-- 
Derek Parnell
Melbourne, Australia
skype: derek.j.parnell
Feb 19 2009
prev sibling parent Christopher Wright <dhasenan gmail.com> writes:
Derek Parnell wrote:

 "I don't think I like X" means that I *know* that I don't like X, there is
 no uncertainty.



Not so. That is the only *reasonable* interpretation, but the person 
might not have any opinion whatsoever on the issue of whether they like 
X, and know that.
Feb 19 2009
prev sibling next sibling parent Jarrett Billingsley <jarrett.billingsley gmail.com> writes:
On Thu, Feb 19, 2009 at 11:07 AM, bearophile <bearophileHUGS lycos.com> wrote:


If you don't have a semicolon, you get a simple parser error. That is not a
bug.<



 Wikipedia agrees with me:

 http://en.wikipedia.org/wiki/Software_bug

A software bug is an error, flaw, mistake, failure, or fault in a computer
program that prevents it from behaving as intended (e.g., producing an
incorrect or unexpected result).<



 So a parser error is a bug too, despite the compiler will help you find it in
a moment.



The representation of a program is separate from its semantics, and
the semantics are only knowable if the representation is correct.
Bugs are semantic errors.  If your program cannot be compiled due to
an incorrect representation, you can't tell whether the program's
semantics are correct.  Therefore, an incorrect representation is not
a bug.


 I have written and debugged many times "mistakes" like:

 foreach (a, b, iterable)
 foreach (a; b; iterable)
 foreach (a; b, iterable)

 And probably I am not the only one :-)
 ...
 But having a language that is more bug-prone isn't good.



And when I used C# from some internship work, I kept writing
"foreach(string s; something)".  And the same with Java, which uses
"for(String s : something)".  Does that mean C#'s and Java's syntaxes
are wrong and they should be changed to the semicolon because I made
mistakes?

The point I'm making here is it doesn't matter whether it uses 'in' or
';' or ':' or '(%)#* ' to separate the loop indices from the container
expression, because there will always be people who feel that another
syntax is better or more natural.  Instead of arguing over minute
details like this, let's worry about the important things, like the
semantics of foreach loops.


That has little to nothing to do with it.  'in' in a foreach loop header is
unambiguous to parse.<



 You may have missed the discussion last time, when I think Walter has
explained what I have told you the problem about the compilation stages.



I know very well what Walter is talking about when he mentions the
independence of the stages of compilation.  I've written a compiler
too, based on D's and with a similar staged compilation strategy.  The
fact is that there is no grammar production in which 'in' can be
ambiguous within the context of a foreach loop header.

foreach(something; x)

You can replace ';' with 'in' or 'out' or 'forble' or pretty much any
other token, as long as it doesn't cause ambiguity with the
'something' part.  'something' is not an expression, so there is no
way that the compiler could mistake 'in' for an expression there.  It
doesn't require any semantic analysis to determine what 'in' means in
that context.


and changing it to 'in' does not really benefit anyone except you, since you're
so goddamned attached to Python's syntax.<



 Thank you, I attach myself to things I think are good and well designed.
 And Python isn't the only language that uses "in" with a "for-each" :-)



And D isn't the only language that _doesn't_ use 'in'.  And?  What's your point?


Use Delight, ffs.<



 I don't know what "ffs" means, and I'm on Windows again now :-)



"For f**k's sake."  It's an expression of exasperation.
Feb 19 2009
prev sibling next sibling parent Jarrett Billingsley <jarrett.billingsley gmail.com> writes:
On Thu, Feb 19, 2009 at 11:45 AM, Ary Borenszweig <ary esperanto.org.ar> wrote:


 Also, "I think I don't like X" is not proper English.  Say "I don't think
 I like X" or just "I don't like X" instead.<






 To Jarrett: why isn't it proper English? It makes sense to me.



Andrei did a pretty good job of explaining indirectly why it's wrong ;)

If you say "I think <something about myself>", it sounds very strange,
because it sounds like you don't know what's going on in your own
brain.  "I think X" often means "I'm not sure of X", so saying that
you're unsure of what you do or don't like sounds odd indeed.
Feb 19 2009
prev sibling next sibling parent reply Jarrett Billingsley <jarrett.billingsley gmail.com> writes:
On Thu, Feb 19, 2009 at 4:06 PM, Derek Parnell <derek psych.ward> wrote:

 On Thu, 19 Feb 2009 10:45:44 -0500, Jarrett Billingsley wrote:


 Also, "I think I don't like X" is not proper English.  Say "I don't
 think I like X" or just "I don't like X" instead.



 Of course its proper English.

 "I think I don't like X" means that I'm undecided about whether or not I
 like X but I probably do not like it.

 "I don't think I like X" means that I *know* that I don't like X, there is
 no uncertainty.



See, it's funny, because I would think "I don't think I like X" means
that I'm undecided about whether or not I like X but I probably don't;
and that "I don't like X" means that I know that I don't like it.  "I
think I don't X" just sounds very unnatural to me.
Feb 19 2009
parent "Nick Sabalausky" <a a.a> writes:
"Jarrett Billingsley" <jarrett.billingsley gmail.com> wrote in message 
news:mailman.799.1235084361.22690.digitalmars-d puremagic.com...

 On Thu, Feb 19, 2009 at 4:06 PM, Derek Parnell <derek psych.ward> wrote:

 On Thu, 19 Feb 2009 10:45:44 -0500, Jarrett Billingsley wrote:


 Also, "I think I don't like X" is not proper English.  Say "I don't
 think I like X" or just "I don't like X" instead.



 Of course its proper English.

 "I think I don't like X" means that I'm undecided about whether or not I
 like X but I probably do not like it.

 "I don't think I like X" means that I *know* that I don't like X, there 
 is
 no uncertainty.



 See, it's funny, because I would think "I don't think I like X" means
 that I'm undecided about whether or not I like X but I probably don't;
 and that "I don't like X" means that I know that I don't like it.  "I
 think I don't X" just sounds very unnatural to me.



I think I don't like "I think I don't like X".

Sorry, I had to say it ;)
Feb 19 2009
prev sibling next sibling parent Bill Baxter <wbaxter gmail.com> writes:
On Fri, Feb 20, 2009 at 10:48 AM, Ary Borenszweig <ary esperanto.org.ar> wr=
ote:

 Jarrett Billingsley escribi=F3:

 On Thu, Feb 19, 2009 at 11:45 AM, Ary Borenszweig <ary esperanto.org.ar>
 wrote:


 Also, "I think I don't like X" is not proper English.  Say "I don't
 think
 I like X" or just "I don't like X" instead.<






 To Jarrett: why isn't it proper English? It makes sense to me.



 Andrei did a pretty good job of explaining indirectly why it's wrong ;)

 If you say "I think <something about myself>", it sounds very strange,
 because it sounds like you don't know what's going on in your own
 brain.  "I think X" often means "I'm not sure of X", so saying that
 you're unsure of what you do or don't like sounds odd indeed.






And yet sometimes that is exactly the case.

---bb
Feb 19 2009
prev sibling next sibling parent Jarrett Billingsley <jarrett.billingsley gmail.com> writes:
On Thu, Feb 19, 2009 at 9:01 PM, Bill Baxter <wbaxter gmail.com> wrote:

 And yet sometimes that is exactly the case.



Perhaps I'm just too absolute ;)
Feb 19 2009
prev sibling parent Jarrett Billingsley <jarrett.billingsley gmail.com> writes:
On Thu, Feb 19, 2009 at 6:31 PM, Derek Parnell <derek psych.ward> wrote:

 See, it's funny, because I would think "I don't think I like X" means
 that I'm undecided about whether or not I like X but I probably don't;
 and that "I don't like X" means that I know that I don't like it.  "I
 think I don't X" just sounds very unnatural to me.



 Maybe is a difference between American English and Australian English?



You might have something there.
Feb 19 2009