Curiously, both Ruby and PHP, both with the same relative precedence as Perl for the ternary and assignment operators, bend the rules differently. For example, this Ruby program: 

config = ''
fred = 42
fred == 42 ? config = 'k1' : config = 'k2'
print "config=#{config}\n"

[download]
and PHP program: 
<?php
$config = '';
$fred = 42;
$fred == 42 ? $config = 'k1' : $config = 'k2';
echo "config=$config\n";
?>

[download]
both run without error, but, unlike Perl (which produces config=k2), both Ruby and PHP produce config=k1.

Arguably, all three languages should produce a syntax error.

Update: gcc produces a syntax error "f.c:6: error: lvalue required as left operand of assignment" with this test program (further update: g++ compiles it happily though and with the same semantics as the Ruby and PHP test programs): 

#include <stdio.h>
int main()
{
   int config = 0;
   int fred = 42;
   fred == 42 ? config = 1 : config = 2;
   printf("config=%d\n", config);
   return 0;
}

[download]
Adding parentheses to line 6: 
   fred == 42 ? (config = 1) : (config = 2);  // this works
   fred == 42 ?  config = 1  : (config = 2);  // also works
   fred == 42 ? (config = 1) : config = 2;    // syntax error

[download]
makes it work the same as the Ruby and PHP test programs.

In reply to Re^2: Surprised by Perl parse of ternary operator by eyepopslikeamosquito
in thread Surprised by Perl parse of ternary operator by eyepopslikeamosquito

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