*a = 9 # => [9]
a # => [9]
*a # => compile error
*b=*a # => [9]
*b = a # => [[9]]
b = a # => [9]
b = *a # => 9 ----- this is amazing ?
···
--
sur
http://expressica.com
Hi --
···
On Thu, 15 Feb 2007, sur max wrote:
*a = 9 # => [9]
a # => [9]
*a # => compile error
*b=*a # => [9]
*b = a # => [[9]]
b = a # => [9]
b = *a # => 9 ----- this is amazing ?
It's doing what it should, I think. *a means: the unarrayed version
of [9], which is 9.
David
--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
(See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)
Splat operator is amazing, but above behaviour can be explained using this:
"If the last lvalue is preceded by an asterisk, all the remaining
rvalues will be collected and
assigned to that lvalue as an array. Similarly, if the last rvalue is
an array, you can
prefix it with an asterisk, which effectively expands it into its
constituent values in
place. (This is not necessary if the rvalue is the only thing on the
right side—the array
will be expanded automatically.)
"
See, nothing wierd out there. 
PS: Taken from PickAxe Verbatim.
···
On 2/15/07, sur max <sur.max@gmail.com> wrote:
*a = 9 # => [9]
a # => [9]
*a # => compile error
*b=*a # => [9]
*b = a # => [[9]]
b = a # => [9]
b = *a # => 9 ----- this is amazing ?
--
gnufied
-----------
There was only one Road; that it was like a great river: its springs
were at every doorstep, and every path was its tributary.
http://people.inxsasia.com/~hemant
Hi --
*a = 9 # => [9]
a # => [9]
*a # => compile error
*b=*a # => [9]
*b = a # => [[9]]
b = a # => [9]
b = *a # => 9 ----- this is amazing ?Splat operator is amazing, but above behaviour can be explained using this:
"If the last lvalue is preceded by an asterisk, all the remaining
rvalues will be collected and
assigned to that lvalue as an array. Similarly, if the last rvalue is
an array, you can
prefix it with an asterisk, which effectively expands it into its
constituent values in
place. (This is not necessary if the rvalue is the only thing on the
right sidethe array
will be expanded automatically.)
"
See, nothing wierd out there.
Another way to look at it, which I think covers all of the above
cases, is:
*x equals without the
So:
*a = 9 # a without the is 9, so a == [9]
*b = a # b without the is [9], so b == [[9]]
b = *a # b == [9] without the , so b == 9
That's why I call it the "unary unarray" operator.
David
···
On Fri, 16 Feb 2007, hemant wrote:
On 2/15/07, sur max <sur.max@gmail.com> wrote:
--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
(See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)
ok and its like ....
*a = 9
a << 5
b = *a # => [9,5]
is there any relation in this n above ?
···
On 2/15/07, dblack@wobblini.net <dblack@wobblini.net> wrote:
Hi --
On Fri, 16 Feb 2007, hemant wrote:
> On 2/15/07, sur max <sur.max@gmail.com> wrote:
>> *a = 9 # => [9]
>> a # => [9]
>> *a # => compile error
>> *b=*a # => [9]
>> *b = a # => [[9]]
>> b = a # => [9]
>> b = *a # => 9 ----- this is amazing ?
>
> Splat operator is amazing, but above behaviour can be explained using
this:
>
> "If the last lvalue is preceded by an asterisk, all the remaining
> rvalues will be collected and
> assigned to that lvalue as an array. Similarly, if the last rvalue is
> an array, you can
> prefix it with an asterisk, which effectively expands it into its
> constituent values in
> place. (This is not necessary if the rvalue is the only thing on the
> right side—the array
> will be expanded automatically.)
> "
> See, nothing wierd out there.Another way to look at it, which I think covers all of the above
cases, is:*x equals without the
So:
*a = 9 # a without the is 9, so a == [9]
*b = a # b without the is [9], so b == [[9]]
b = *a # b == [9] without the , so b == 9That's why I call it the "unary unarray" operator.
David
--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
(See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)
--
sur
http://expressica.com
Hi --
>> *a = 9 # => [9]
>> a # => [9]
>> *a # => compile error
>> *b=*a # => [9]
>> *b = a # => [[9]]
>> b = a # => [9]
>> b = *a # => 9 ----- this is amazing ?
>
> Splat operator is amazing, but above behaviour can be explained using this:
>
> "If the last lvalue is preceded by an asterisk, all the remaining
> rvalues will be collected and
> assigned to that lvalue as an array. Similarly, if the last rvalue is
> an array, you can
> prefix it with an asterisk, which effectively expands it into its
> constituent values in
> place. (This is not necessary if the rvalue is the only thing on the
> right side—the array
> will be expanded automatically.)
> "
> See, nothing wierd out there.
Well I cannot speak for OP but what puzzles me is
a=[42] # sorry 9 is not the number
*a ==> error # gotta check with 1.9 an 2.0 at home
I would think that this expression can/could/should/might perfectly
evaluate to 42
look at this other oddity the following code is completely legal and POLS(1)
def x *args
return *args
end
(1) in the sense that a,b,c = x 1,2,3 sets a to 1, b to 2 and c to 3
and x is a NOP
but return in the last statement is optional, or is it not I know
you are not falling into my trap !
I see no reason however why
def x *args
*args
end
should not be legal
Another way to look at it, which I think covers all of the above
cases, is:*x equals without the
unless it causes an error, which is not really very sexy behavior IMHO.
<snip>
That's why I call it the "unary unarray" operator.
Which is a good mnemonic idea! Very didactic I feel!
David
--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
(See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)
Cheers
Robert
···
On 2/15/07, dblack@wobblini.net <dblack@wobblini.net> wrote:
On Fri, 16 Feb 2007, hemant wrote:
> On 2/15/07, sur max <sur.max@gmail.com> wrote:
--
We have not succeeded in answering all of our questions.
In fact, in some ways, we are more confused than ever.
But we feel we are confused on a higher level and about more important things.
-Anonymous
ok and its like ....
*a = 9
remember a would become an array here.because as explained above,if
lvalue is prefixed with asterisk, then rvalue is collected and
assigned to lvalue as an array.
a << 5
append 5 to a (which is an array)
b = *a # => [9,5]
is there any relation in this n above ?
Now, above is pretty standard ruby behaviour, it has nothing to do
with * operator, as usual * extracts the values from a(which was an
array).
For example:
irb(main):062:0> b = 9,5
[9, 5]
irb(main):063:0> b
[9, 5]
irb(main):064:0> b,c = 9,5
[9, 5]
irb(main):065:0> b
9
irb(main):066:0> c
5
···
On 2/15/07, sur max <sur.max@gmail.com> wrote:
On 2/15/07, dblack@wobblini.net <dblack@wobblini.net> wrote:
>
> Hi --
>
> On Fri, 16 Feb 2007, hemant wrote:
>
> > On 2/15/07, sur max <sur.max@gmail.com> wrote:
> >> *a = 9 # => [9]
> >> a # => [9]
> >> *a # => compile error
> >> *b=*a # => [9]
> >> *b = a # => [[9]]
> >> b = a # => [9]
> >> b = *a # => 9 ----- this is amazing ?
> >
> > Splat operator is amazing, but above behaviour can be explained using
> this:
> >
> > "If the last lvalue is preceded by an asterisk, all the remaining
> > rvalues will be collected and
> > assigned to that lvalue as an array. Similarly, if the last rvalue is
> > an array, you can
> > prefix it with an asterisk, which effectively expands it into its
> > constituent values in
> > place. (This is not necessary if the rvalue is the only thing on the
> > right side—the array
> > will be expanded automatically.)
> > "
> > See, nothing wierd out there.
>
> Another way to look at it, which I think covers all of the above
> cases, is:
>
> *x equals without the
>
> So:
>
> *a = 9 # a without the is 9, so a == [9]
> *b = a # b without the is [9], so b == [[9]]
> b = *a # b == [9] without the , so b == 9
>
> That's why I call it the "unary unarray" operator.
>
> David
>
> --
> Q. What is THE Ruby book for Rails developers?
> A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
> (See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
> Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
> A. Ruby Power and Light, LLC (http://www.rubypal.com)
>--
sur
http://expressica.com
--
gnufied
-----------
There was only one Road; that it was like a great river: its springs
were at every doorstep, and every path was its tributary.
http://people.inxsasia.com/~hemant
def a *args
*args
end
is very much illegal .... giving compile error
and with return keyword it works very fine.
I am still feeling that point(s) still lasts
Again i am repeating the same old story ....
*a = 9 # i like this number 
b = *a # => 9 ------- mind it, it is Fixnum
here it seems true "*x equals without the "
a << 5
b = *a # => [9,5] ------- an Array
here it seems false "*x equals without the "
moreover
*a # => compile error
is it strange behavior ? or pretty digestible ?
···
On 2/15/07, Robert Dober <robert.dober@gmail.com> wrote:
On 2/15/07, dblack@wobblini.net <dblack@wobblini.net> wrote:
> Hi --
>
> On Fri, 16 Feb 2007, hemant wrote:
>
> > On 2/15/07, sur max <sur.max@gmail.com> wrote:
> >> *a = 9 # => [9]
> >> a # => [9]
> >> *a # => compile error
> >> *b=*a # => [9]
> >> *b = a # => [[9]]
> >> b = a # => [9]
> >> b = *a # => 9 ----- this is amazing ?
> >
> > Splat operator is amazing, but above behaviour can be explained using
this:
> >
> > "If the last lvalue is preceded by an asterisk, all the remaining
> > rvalues will be collected and
> > assigned to that lvalue as an array. Similarly, if the last rvalue is
> > an array, you can
> > prefix it with an asterisk, which effectively expands it into its
> > constituent values in
> > place. (This is not necessary if the rvalue is the only thing on the
> > right side—the array
> > will be expanded automatically.)
> > "
> > See, nothing wierd out there.Well I cannot speak for OP but what puzzles me is
a=[42] # sorry 9 is not the number
*a ==> error # gotta check with 1.9 an 2.0 at homeI would think that this expression can/could/should/might perfectly
evaluate to 42
look at this other oddity the following code is completely legal and
POLS(1)
def x *args
return *args
end
(1) in the sense that a,b,c = x 1,2,3 sets a to 1, b to 2 and c to 3
and x is a NOPbut return in the last statement is optional, or is it not
you are not falling into my trap !I see no reason however why
def x *args
*args
end
should not be legal
>
> Another way to look at it, which I think covers all of the above
> cases, is:
>
> *x equals without the
unless it causes an error, which is not really very sexy behavior IMHO.
>
<snip>
> That's why I call it the "unary unarray" operator.
Which is a good mnemonic idea! Very didactic I feel!
>
> David
>
> --
> Q. What is THE Ruby book for Rails developers?
> A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
> (See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
> Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
> A. Ruby Power and Light, LLC (http://www.rubypal.com)
>
Cheers
Robert--
We have not succeeded in answering all of our questions.
In fact, in some ways, we are more confused than ever.
But we feel we are confused on a higher level and about more important
things.
-Anonymous
--
sur
http://expressica.com
Hi --
Well I cannot speak for OP but what puzzles me is
a=[42] # sorry 9 is not the number
*a ==> error # gotta check with 1.9 an 2.0 at homeI would think that this expression can/could/should/might perfectly
evaluate to 42 look at this other oddity the following code is
completely legal and POLS(1)
def x *args
return *args
end
(1) in the sense that a,b,c = x 1,2,3 sets a to 1, b to 2 and c to 3
and x is a NOPbut return in the last statement is optional, or is it not
you are not falling into my trap !I see no reason however why
def x *args
*args
end
should not be legal
I can't think of a case where you'd need it, since the arguments would
just get wrapped up in an array anyway. Also, *args is basically
equivalent to a bare list, and you can't do:
def x
1,2,3
end
David
···
On Fri, 16 Feb 2007, Robert Dober wrote:
--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
(See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)
Thats pretty known.
And even this too...
a = 2,3,4,5,6 # => [2,3,4,5,6]
b, = a --- now this is beauty
b # => 2
b,c = a
b # => 2
c # => 3
and so...
b,c,d = a
but still didnt get clear .... is it like we can use *a for assigning to
some other var ONLY ?
···
On 2/15/07, hemant <gethemant@gmail.com> wrote:
On 2/15/07, sur max <sur.max@gmail.com> wrote:
> ok and its like ....
>
> *a = 9remember a would become an array here.because as explained above,if
lvalue is prefixed with asterisk, then rvalue is collected and
assigned to lvalue as an array.> a << 5
append 5 to a (which is an array)
> b = *a # => [9,5]
> is there any relation in this n above ?Now, above is pretty standard ruby behaviour, it has nothing to do
with * operator, as usual * extracts the values from a(which was an
array).For example:
irb(main):062:0> b = 9,5
[9, 5]
irb(main):063:0> b
[9, 5]
irb(main):064:0> b,c = 9,5
[9, 5]
irb(main):065:0> b
9
irb(main):066:0> c
5>
> On 2/15/07, dblack@wobblini.net <dblack@wobblini.net> wrote:
> >
> > Hi --
> >
> > On Fri, 16 Feb 2007, hemant wrote:
> >
> > > On 2/15/07, sur max <sur.max@gmail.com> wrote:
> > >> *a = 9 # => [9]
> > >> a # => [9]
> > >> *a # => compile error
> > >> *b=*a # => [9]
> > >> *b = a # => [[9]]
> > >> b = a # => [9]
> > >> b = *a # => 9 ----- this is amazing ?
> > >
> > > Splat operator is amazing, but above behaviour can be explained
using
> > this:
> > >
> > > "If the last lvalue is preceded by an asterisk, all the remaining
> > > rvalues will be collected and
> > > assigned to that lvalue as an array. Similarly, if the last rvalue
is
> > > an array, you can
> > > prefix it with an asterisk, which effectively expands it into its
> > > constituent values in
> > > place. (This is not necessary if the rvalue is the only thing on the
> > > right side—the array
> > > will be expanded automatically.)
> > > "
> > > See, nothing wierd out there.
> >
> > Another way to look at it, which I think covers all of the above
> > cases, is:
> >
> > *x equals without the
> >
> > So:
> >
> > *a = 9 # a without the is 9, so a == [9]
> > *b = a # b without the is [9], so b == [[9]]
> > b = *a # b == [9] without the , so b == 9
> >
> > That's why I call it the "unary unarray" operator.
> >
> > David
> >
> > --
> > Q. What is THE Ruby book for Rails developers?
> > A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
> > (See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
> > Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
> > A. Ruby Power and Light, LLC (http://www.rubypal.com)
> >
>
> --
> sur
> http://expressica.com
>--
gnufied
-----------
There was only one Road; that it was like a great river: its springs
were at every doorstep, and every path was its tributary.
http://people.inxsasia.com/~hemant
--
sur
http://expressica.com
Hi --
def a *args
*args
end
is very much illegal .... giving compile error
and with return keyword it works very fine.I am still feeling that point(s) still lasts
Again i am repeating the same old story ....
*a = 9 # i like this number
b = *a # => 9 ------- mind it, it is Fixnum
here it seems true "*x equals without the "a << 5
b = *a # => [9,5] ------- an Array
here it seems false "*x equals without the "
But you have to consider this:
b = 9,5 # => [9,5]
so "[9,5] without a ", on the rhs, gets turned into an array. I
know it sounds like I'm putting in an extra step... but it really is
consistent in terms of the behavior of * itself.
moreover
*a # => compile erroris it strange behavior ? or pretty digestible ?
What would that mean, though? Or, to put it another way, what could
you possibly do with *a on its own?
David
···
On Fri, 16 Feb 2007, sur max wrote:
--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
(See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)
*a = 9 # i like this number
...
a << 5
b = *a # => [9,5] ------- an Array
here it seems false "*x equals without the "
Actually, the "rule" still applies, in that:
b = *a # where a = [9, 5]
and
b = 9, 5
Have the same effect. You were just forgetting to consider that b
would just slurp them back into an array.
*a # => compile error
This seems to be the only remaining "anomaly".
Jacob Fugal
···
On 2/15/07, sur max <sur.max@gmail.com> wrote:
Hi --
> Well I cannot speak for OP but what puzzles me is
>
> a=[42] # sorry 9 is not the number
> *a ==> error # gotta check with 1.9 an 2.0 at home
>
> I would think that this expression can/could/should/might perfectly
> evaluate to 42 look at this other oddity the following code is
> completely legal and POLS(1)
> def x *args
> return *args
> end
> (1) in the sense that a,b,c = x 1,2,3 sets a to 1, b to 2 and c to 3
> and x is a NOP
>
> but return in the last statement is optional, or is it not
> you are not falling into my trap !
>
> I see no reason however why
> def x *args
> *args
> end
> should not be legalI can't think of a case where you'd need it, since the arguments would
just get wrapped up in an array anyway.
Agreed, but that was *not* my point
Also, *args is basically
equivalent to a bare list, and you can't do:def x
1,2,3
end
def x
return 1,2,3
end
is legal it all is about consistency
1,2,3 vs. return 1,2,3
*rhs vs. lhs = *rhs
I have no idea if one could make it work without breaking a parsable
syntax, I just thought that OP was doing a good job at pointing to
this inconsistency.
We could forbid return *a but can we forbid lhs = *rhs?
I realize I am not smart enough to complain, - and too tired too 
-.
But I also feel that I did not really underline the inconsistency in
the syntax so far.
An inconsistency that is not really troubling me but which is here nevertheless.
Well that is pretty much what I wanted to say.
Cheers
Robert
···
On 2/15/07, dblack@wobblini.net <dblack@wobblini.net> wrote:
On Fri, 16 Feb 2007, Robert Dober wrote:
David
--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
(See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)
--
We have not succeeded in answering all of our questions.
In fact, in some ways, we are more confused than ever.
But we feel we are confused on a higher level and about more important things.
-Anonymous
Thats pretty known.
And even this too...
Again, I am sorry to bore you with little known things.
a = 2,3,4,5,6 # => [2,3,4,5,6]
b, = a --- now this is beauty
b # => 2
b,c = a
b # => 2
c # => 3
and so...
b,c,d = abut still didnt get clear .... is it like we can use *a for assigning to
some other var ONLY ?
I would like to think so, thats why we got syntax error exception
tossed at our face when we do:
*a = 9
*a
I guess ruby interpretor is doing tough job of differentiating splat
from multiplication operator and it decided to not allow you to do
that.
However, you can very well do
a = 9
+a
++a
-a
Again, I might be stating the obvious.
···
On 2/15/07, sur max <sur.max@gmail.com> wrote:
On 2/15/07, hemant <gethemant@gmail.com> wrote:
>
> On 2/15/07, sur max <sur.max@gmail.com> wrote:
> > ok and its like ....
> >
> > *a = 9
>
> remember a would become an array here.because as explained above,if
> lvalue is prefixed with asterisk, then rvalue is collected and
> assigned to lvalue as an array.
>
> > a << 5
>
> append 5 to a (which is an array)
>
> > b = *a # => [9,5]
> > is there any relation in this n above ?
>
> Now, above is pretty standard ruby behaviour, it has nothing to do
> with * operator, as usual * extracts the values from a(which was an
> array).
>
> For example:
>
> irb(main):062:0> b = 9,5
> [9, 5]
> irb(main):063:0> b
> [9, 5]
> irb(main):064:0> b,c = 9,5
> [9, 5]
> irb(main):065:0> b
> 9
> irb(main):066:0> c
> 5
>
> >
> > On 2/15/07, dblack@wobblini.net <dblack@wobblini.net> wrote:
> > >
> > > Hi --
> > >
> > > On Fri, 16 Feb 2007, hemant wrote:
> > >
> > > > On 2/15/07, sur max <sur.max@gmail.com> wrote:
> > > >> *a = 9 # => [9]
> > > >> a # => [9]
> > > >> *a # => compile error
> > > >> *b=*a # => [9]
> > > >> *b = a # => [[9]]
> > > >> b = a # => [9]
> > > >> b = *a # => 9 ----- this is amazing ?
> > > >
> > > > Splat operator is amazing, but above behaviour can be explained
> using
> > > this:
> > > >
> > > > "If the last lvalue is preceded by an asterisk, all the remaining
> > > > rvalues will be collected and
> > > > assigned to that lvalue as an array. Similarly, if the last rvalue
> is
> > > > an array, you can
> > > > prefix it with an asterisk, which effectively expands it into its
> > > > constituent values in
> > > > place. (This is not necessary if the rvalue is the only thing on the
> > > > right side—the array
> > > > will be expanded automatically.)
> > > > "
> > > > See, nothing wierd out there.
> > >
> > > Another way to look at it, which I think covers all of the above
> > > cases, is:
> > >
> > > *x equals without the
> > >
> > > So:
> > >
> > > *a = 9 # a without the is 9, so a == [9]
> > > *b = a # b without the is [9], so b == [[9]]
> > > b = *a # b == [9] without the , so b == 9
> > >
> > > That's why I call it the "unary unarray" operator.
> > >
> > > David
> > >
> > > --
> > > Q. What is THE Ruby book for Rails developers?
> > > A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
> > > (See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
> > > Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
> > > A. Ruby Power and Light, LLC (http://www.rubypal.com)
> > >
> >
> > --
> > sur
> > http://expressica.com
> >
>
> --
> gnufied
> -----------
> There was only one Road; that it was like a great river: its springs
> were at every doorstep, and every path was its tributary.
> http://people.inxsasia.com/~hemant
>--
sur
http://expressica.com
--
gnufied
-----------
There was only one Road; that it was like a great river: its springs
were at every doorstep, and every path was its tributary.
http://people.inxsasia.com/~hemant
Hi --
*a = 9 # i like this number
...
a << 5
b = *a # => [9,5] ------- an Array
here it seems false "*x equals without the "Actually, the "rule" still applies, in that:
b = *a # where a = [9, 5]
and
b = 9, 5
Have the same effect. You were just forgetting to consider that b
would just slurp them back into an array.*a # => compile error
This seems to be the only remaining "anomaly".
It isn't, though:
irb#1(main):017:0> a = [9,5]
=> [9, 5]
irb#1(main):018:0> *a
SyntaxError: compile error
(irb#1):18: syntax error
from (irb#1):18
irb#1(main):019:0> 9,5
SyntaxError: compile error
(irb#1):19: syntax error
from (irb#1):19
David
···
On Fri, 16 Feb 2007, Jacob Fugal wrote:
On 2/15/07, sur max <sur.max@gmail.com> wrote:
--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
(See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)
if we even consider it this way ....
*a = 9
a << 5
i mean a = [9,5]
and now considering it as...
a # => [9,5]
*a # => 9,5 --- (on assignment)
so the following should be true
b = a # => [9,5] ----- true
b = *a # => [9,5] ----- true , b is re-wrapping 9,5 as [9,5]
b = [a,6] # => [[9,5],6] ---- true, naturally
b = [*a,6] # => [9,5,6] ----- false, compile error
b = *a,6 # => [9,5,6] ----- false, compile error
···
On 2/16/07, dblack@wobblini.net <dblack@wobblini.net> wrote:
Hi --
On Fri, 16 Feb 2007, Jacob Fugal wrote:
> On 2/15/07, sur max <sur.max@gmail.com> wrote:
>> *a = 9 # i like this number
> ...
>> a << 5
>> b = *a # => [9,5] ------- an Array
>> here it seems false "*x equals without the "
>
> Actually, the "rule" still applies, in that:
>
> b = *a # where a = [9, 5]
>
> and
>
> b = 9, 5
>
> Have the same effect. You were just forgetting to consider that b
> would just slurp them back into an array.
>
>> *a # => compile error
>
> This seems to be the only remaining "anomaly".It isn't, though:
irb#1(main):017:0> a = [9,5]
=> [9, 5]
irb#1(main):018:0> *a
SyntaxError: compile error
(irb#1):18: syntax error
from (irb#1):18
irb#1(main):019:0> 9,5
SyntaxError: compile error
(irb#1):19: syntax error
from (irb#1):19David
--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
(See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)
--
sur
http://expressica.com
Hi --
if we even consider it this way ....
*a = 9
a << 5
i mean a = [9,5]and now considering it as...
a # => [9,5]
*a # => 9,5 --- (on assignment)so the following should be true
b = a # => [9,5] ----- true
b = *a # => [9,5] ----- true , b is re-wrapping 9,5 as [9,5]
b = [a,6] # => [[9,5],6] ---- true, naturally
b = [*a,6] # => [9,5,6] ----- false, compile error
b = *a,6 # => [9,5,6] ----- false, compile error
In Ruby 1.8 and earlier, you can only do the * at the end of an array.
That's changing, though. This is from a November version of Ruby 1.9:
irb(main):001:0> a = [9,5]
=> [9, 5]
irb(main):002:0> b = 9,5,6
=> [9, 5, 6]
irb(main):003:0> b = *a, 6
=> [9, 5]
irb(main):004:0> b = [*a, 6]
=> [9, 5, 6]
I don't really understand the third one. I would have expected it to
be the same as the second. I haven't tried a more recent 1.9 version,
though -- maybe it's been changed.
David
···
On Fri, 16 Feb 2007, sur max wrote:
--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
(See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)
fr: sur max [mailto:sur.max@gmail.com] :
# b = [*a,6] # => [9,5,6] ----- false, compile error
# b = *a,6 # => [9,5,6] ----- false, compile error
pls be careful. "*" op will splat. so here ruby is just telling/policing you not too.
I always treat splat op as a black hole. this way i make less mistakes.
eg
so this is allowed,
irb(main):050:0> b,*a=1,2,3,4
=> [1, 2, 3, 4]
irb(main):052:0> a
=> [2, 3, 4]
this one is not,
irb(main):053:0> b,*a,c=1,2,3,4
SyntaxError: compile error
(irb):53: syntax error, unexpected ',', expecting '=' b,*a,c=1,2,3,4
irb(main):054:0>
ruby, is telling me that "*a" is a blackhole. The c does "not matter".
so is this one,
irb(main):056:0> *a
SyntaxError: compile error
(irb):56: syntax error, unexpected '\n', expecting '='
that's a blackhole without a hole or opening. feed it 
again, another stupid blackhole reasoning.
nonetheless, splat is a very sweet yet too powerful operator. I feel that splat op digress oo-ness. But i believe it's not oo for oo's sake. It's solving problems and discovering brilliant solutions. Ruby does it w ease and fun. Sometimes, i feel ruby will trend toward object and method unification, wherein objects can be methods and vice versa. arggh, like matter <==> energy. maybe, a superproc or superlamdba in the future... i'll stop now
drive w caution, (black)holes ahead.
sorry for the long post fr a nuby.
kind regards -botp
gr8...
sounds satisfactory !!
i will try it on 1.9
Thanks a lot to all !!
···
On 2/16/07, dblack@wobblini.net <dblack@wobblini.net> wrote:
Hi --
On Fri, 16 Feb 2007, sur max wrote:
> if we even consider it this way ....
> *a = 9
> a << 5
> i mean a = [9,5]
>
> and now considering it as...
>
> a # => [9,5]
> *a # => 9,5 --- (on assignment)
>
> so the following should be true
>
> b = a # => [9,5] ----- true
> b = *a # => [9,5] ----- true , b is re-wrapping 9,5 as [9,5]
> b = [a,6] # => [[9,5],6] ---- true, naturally
> b = [*a,6] # => [9,5,6] ----- false, compile error
> b = *a,6 # => [9,5,6] ----- false, compile errorIn Ruby 1.8 and earlier, you can only do the * at the end of an array.
That's changing, though. This is from a November version of Ruby 1.9:irb(main):001:0> a = [9,5]
=> [9, 5]
irb(main):002:0> b = 9,5,6
=> [9, 5, 6]
irb(main):003:0> b = *a, 6
=> [9, 5]
irb(main):004:0> b = [*a, 6]
=> [9, 5, 6]I don't really understand the third one. I would have expected it to
be the same as the second. I haven't tried a more recent 1.9 version,
though -- maybe it's been changed.David
--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
(See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)
--
sur
http://expressica.com
fr: sur max [mailto:sur.max@gmail.com] :
# b = [*a,6] # => [9,5,6] ----- false, compile error
# b = *a,6 # => [9,5,6] ----- false, compile errorpls be careful. "*" op will splat. so here ruby is just telling/policing you not too.
I always treat splat op as a black hole. this way i make less mistakes.
eg
so this is allowed,
irb(main):050:0> b,*a=1,2,3,4
=> [1, 2, 3, 4]
irb(main):052:0> a
=> [2, 3, 4]this one is not,
irb(main):053:0> b,*a,c=1,2,3,4
SyntaxError: compile error
(irb):53: syntax error, unexpected ',', expecting '=' b,*a,c=1,2,3,4
irb(main):054:0>ruby, is telling me that "*a" is a blackhole. The c does "not matter".
Botp
this is a very nice analogy, however it does only hold for the LHS
i.e. assignment target and formal parameter lists.
On the LHS a splatted expression is an *infinite* consumer a blackhole
On the RHS a splatted expression is a *finite* producer though.
I see no reason why ..., *a, ... should be forbidden on the RHS.
to ... = *(a + [b])
I'd prefer
... = *a, b
Side note to David:
after a night of consideration I do not believe that there any
syntactical problems
the splat operator already being allowed in front of parenthesis.
so is this one,
irb(main):056:0> *a
SyntaxError: compile error
(irb):56: syntax error, unexpected '\n', expecting '='that's a blackhole without a hole or opening. feed it
as mentioned above we are in the producer case here
again, another stupid blackhole reasoning.
I would not go that far
nonetheless, splat is a very sweet yet too powerful operator.
I feel that splat op digress oo-ness. But i believe it's not oo for
oo's sake. It's solving problems and discovering brilliant solutions.
Ruby does it w ease and fun. Sometimes, i feel ruby will trend toward
object and method unification, wherein objects can be methods and vice
versa. arggh, like matter <==> energy. maybe, a superproc or
superlamdba in the future... i'll stop now
You might have a point though
drive w caution, (black)holes ahead.
sorry for the long post fr a nuby.
kind regards -botp
Cheers
Robert
···
On 2/16/07, Peña, Botp <botp@delmonte-phil.com> wrote:
--
We have not succeeded in answering all of our questions.
In fact, in some ways, we are more confused than ever.
But we feel we are confused on a higher level and about more important things.
-Anonymous