Re: Fisher-Yates shuffle
On Fri, Apr 12, 2002 at 02:14:36PM -0700, Erik Steven Harrison wrote:
--
On Fri, 12 Apr 2002 18:27:11
abigail wrote:
On Fri, Apr 12, 2002 at 04:42:07PM +0100, Piers Cawley wrote:
[EMAIL PROTECTED] writes:
Why isn't
if %foo {key} {print Hello 1}
equivalent with the perl5 syntax:
if (%foo) {key} {print Hello 1}
Which keyword is it expecting?
Keyword /els(e|if)/, or end of line, or semicolon. Sorry badly phrased
on my part. The closing brace of {key} only ends the statement if it
As i understand it (Tell me if I'm wrong) This
%hash {key};
will not work, because space between the hashname and the brace was no longer
allowed. This allows for
Will not work is not correct. %hash {key} is parsed as an expression
followed by a block. Whether that will work depends on the context.
'if' for instance is followed by an expression and a block..., so
if %hash {key}
*will* work, except it does something totally different than one might
expect.
if %hash{key} { ... }
and also
if $scalar { ... }.
The only other white space rule is that white space after the closing brace of a
closure, when that closure is the last argument of a user defined sub get's treated
as a semicolon if there is nothing else on that line. This allows custom iterators to
parse (or appear to parse) like builtins.
myforeach @arry, %hash, $scalar {
...
}
#No semicolon required!
What problems does this seem to cause - I don't see anything wrong. I don't see how
(except in the case of closure as last argument) how it matters one way or another
what kind white space appears between tokens.
What am I missing?
What you are missing is the new white space rule:
\s+{ }
shall be always be a block. Hence the difference between
%hash {foo} and %hash{foo}.
Abigail
Re: Fisher-Yates shuffle
- Original Message -
From: [EMAIL PROTECTED]
On Fri, Apr 12, 2002 at 04:42:07PM +0100, Piers Cawley wrote:
[EMAIL PROTECTED] writes:
Why isn't
if %foo {key} {print Hello 1}
equivalent with the perl5 syntax:
if (%foo) {key} {print Hello 1}
Which keyword is it expecting?
Keyword /els(e|if)/, or end of line, or semicolon. Sorry badly phrased
on my part. The closing brace of {key} only ends the statement if it
is followed by /\s*$/, or a semicolon.
You've got to be kidding. That makes the whitespace rules even more
insane; your program can behave quite differently wether there's a space,
a newline, or nothing between two tokens. Wonderful! People who tend
to use -e all the time (like me) will love it. (Not!) Pasting code into
IRC will be so much more fun.
I don't think it's all that insane, Perl has history with implied
semicolons.
Perl today: A semicolon is required after every statement, except before a
closing curly or end of file.
Perl 6: A semicolon is also required after every block, except when the
closing curly is on a line of its own, or it precedes another closing curly
or end of file.
As far as whitespace, you can get around that
if%foo{key}-{printHello} # - and \s{ are kinda equivalent
if%foo-{key};{printHello}
Using - like that would be evil. We should put it in the test suite now...
Ashley Winters
Re: Fisher-Yates shuffle
On Sat, Apr 13, 2002 at 12:51:06AM -0700, Ashley Winters wrote:
Perl today: A semicolon is required after every statement, except before a
closing curly or end of file.
Perl 6: A semicolon is also required after every block, except when the
closing curly is on a line of its own, or it precedes another closing curly
or end of file.
This is incorrect according to the examples in the apocalypse:
if 1 { ...; break; }
die panic: shouldn't see this;
The apocalypse implies that the new rule applies to expression
blocks--as opposed, I think, to statement blocks. As far as I
understand these terms, if always takes statement blocks, so this
rule does not apply.
Who can clear up the confusion?
Andrew
Re: Fisher-Yates shuffle
[EMAIL PROTECTED] writes:
On Fri, Apr 12, 2002 at 04:00:37PM +0100, Piers Cawley wrote:
X-posting to perl6-language
[EMAIL PROTECTED] writes:
As for cleanness, this is my interpretation of how perl6 is going
to work:
%foo = ();
if %foo {key} {print Hello 1}
%foo = ();
if %foo{key} {print Hello 2}
%foo = ();
if %foo{key}{print Hello 3}
Case 1 will print Hello 1; this is a block after the if statement.
No, it will be a syntax error. The first closing brace does not end
the statement, probably something like Block seen when keyword
expected.
Now I am confused. In perl6, we can leave off the the parenthesis
around a condition, and I hope that it isn't required to have
an 'elsif' or 'else' block.
Why isn't
if %foo {key} {print Hello 1}
equivalent with the perl5 syntax:
if (%foo) {key} {print Hello 1}
Which keyword is it expecting?
Keyword /els(e|if)/, or end of line, or semicolon. Sorry badly phrased
on my part. The closing brace of {key} only ends the statement if it
is followed by /\s*$/, or a semicolon.
--
Piers
It is a truth universally acknowledged that a language in
possession of a rich syntax must be in need of a rewrite.
-- Jane Austen?
Re: Fisher-Yates shuffle
On Fri, Apr 12, 2002 at 04:00:37PM +0100, Piers Cawley wrote:
X-posting to perl6-language
[EMAIL PROTECTED] writes:
As for cleanness, this is my interpretation of how perl6 is going
to work:
%foo = ();
if %foo {key} {print Hello 1}
%foo = ();
if %foo{key} {print Hello 2}
%foo = ();
if %foo{key}{print Hello 3}
Case 1 will print Hello 1; this is a block after the if statement.
No, it will be a syntax error. The first closing brace does not end
the statement, probably something like Block seen when keyword
expected.
Now I am confused. In perl6, we can leave off the the parenthesis
around a condition, and I hope that it isn't required to have
an 'elsif' or 'else' block.
Why isn't
if %foo {key} {print Hello 1}
equivalent with the perl5 syntax:
if (%foo) {key} {print Hello 1}
Which keyword is it expecting?
Case 2 will not print anything. The print is in the 'then' part
of the if.
Correct.
Case 3 will be a syntax error - an if statement with a condition,
but not block.
It won't be a syntax error *yet*. If there's a block immediately
following then that will be treated as the 'then' block. If it's the
end of file, or a nonblock, then it'll be a syntax error.
Did the code show anything following it? No? Well, then assume
it isn't there. ;-)
Next time I'll show this to someone, I'll add a semicolon.
Abigail
Re: Fisher-Yates shuffle
On Fri, Apr 12, 2002 at 04:42:07PM +0100, Piers Cawley wrote:
[EMAIL PROTECTED] writes:
Why isn't
if %foo {key} {print Hello 1}
equivalent with the perl5 syntax:
if (%foo) {key} {print Hello 1}
Which keyword is it expecting?
Keyword /els(e|if)/, or end of line, or semicolon. Sorry badly phrased
on my part. The closing brace of {key} only ends the statement if it
is followed by /\s*$/, or a semicolon.
You've got to be kidding. That makes the whitespace rules even more
insane; your program can behave quite differently wether there's a space,
a newline, or nothing between two tokens. Wonderful! People who tend
to use -e all the time (like me) will love it. (Not!) Pasting code into
IRC will be so much more fun.
I'll treasure my perl5 sources.
Abigail
Re: Fisher-Yates shuffle
On Fri, Apr 12, 2002 at 04:42:07PM +0100, Piers Cawley wrote:
[EMAIL PROTECTED] writes:
Why isn't
if %foo {key} {print Hello 1}
equivalent with the perl5 syntax:
if (%foo) {key} {print Hello 1}
Which keyword is it expecting?
Keyword /els(e|if)/, or end of line, or semicolon. Sorry badly phrased
on my part. The closing brace of {key} only ends the statement if it
is followed by /\s*$/, or a semicolon.
Hold on--why end of line? That should only make a difference if } is the
only thing on the line...
Luke
Re: Fisher-Yates shuffle
--
On Fri, 12 Apr 2002 18:27:11
abigail wrote:
On Fri, Apr 12, 2002 at 04:42:07PM +0100, Piers Cawley wrote:
[EMAIL PROTECTED] writes:
Why isn't
if %foo {key} {print Hello 1}
equivalent with the perl5 syntax:
if (%foo) {key} {print Hello 1}
Which keyword is it expecting?
Keyword /els(e|if)/, or end of line, or semicolon. Sorry badly phrased
on my part. The closing brace of {key} only ends the statement if it
As i understand it (Tell me if I'm wrong) This
%hash {key};
will not work, because space between the hashname and the brace was no longer allowed.
This allows for
if %hash{key} { ... }
and also
if $scalar { ... }.
The only other white space rule is that white space after the closing brace of a
closure, when that closure is the last argument of a user defined sub get's treated as
a semicolon if there is nothing else on that line. This allows custom iterators to
parse (or appear to parse) like builtins.
myforeach @arry, %hash, $scalar {
...
}
#No semicolon required!
What problems does this seem to cause - I don't see anything wrong. I don't see how
(except in the case of closure as last argument) how it matters one way or another
what kind white space appears between tokens.
What am I missing?
-Erik
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Re: Fisher-Yates shuffle
[EMAIL PROTECTED] writes:
On Fri, Apr 12, 2002 at 04:42:07PM +0100, Piers Cawley wrote:
[EMAIL PROTECTED] writes:
Why isn't
if %foo {key} {print Hello 1}
equivalent with the perl5 syntax:
if (%foo) {key} {print Hello 1}
Which keyword is it expecting?
Keyword /els(e|if)/, or end of line, or semicolon. Sorry badly phrased
on my part. The closing brace of {key} only ends the statement if it
is followed by /\s*$/, or a semicolon.
You've got to be kidding. That makes the whitespace rules even more
insane; your program can behave quite differently wether there's a
space, a newline, or nothing between two tokens. Wonderful! People
who tend to use -e all the time (like me) will love it. (Not!)
Pasting code into IRC will be so much more fun.
So use a semicolon. Or disambiguate with parentheses. Or try and
convince Larry that he's wrong about this. Or use the perl5 syntax
rules that will be understood by default.
--
Piers
It is a truth universally acknowledged that a language in
possession of a rich syntax must be in need of a rewrite.
-- Jane Austen?
