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[perl #79820] Make my $pi := 4; a syntax error

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From:
Nicholas Clark
Date:
November 27, 2010 08:52
Subject:
[perl #79820] Make my $pi := 4; a syntax error
Message ID:
rt-3.6.HEAD-13564-1290787457-642.79820-75-0@perl.org
# New Ticket Created by  Nicholas Clark 
# Please include the string:  [perl #79820]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=79820 >


Currently the := in my $pi := 4; is interpreted as an empty attribute list.
As of 5.12.0, using := here issue a deprecation warning.

No Perl 5 code on CPAN is using :=

If code generators need the flexibility to generate empty attribute lists,
it's trivial to do so by adding a space before the =


I believe that there is consensus that

a: it would be useful to have a binding operator in Perl 5
b: that := is the obvious candidate

hence at some point we need to re-use := for this.

Use of := for binding can't be distinguished from use of it to mean an empty
attribute list. Hence I propose that we make := a syntax error for 5.14, so
that there is at least 1 major version of Perl 5 where any accidental use will
be caught with a clear, comprehensible syntax error message.

Nicholas Clark

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