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Clarifications about *+* and ... with a sub

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Nami-Doc 2014-08-27 12:38:23 +02:00
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@ -488,6 +488,7 @@ sub truthy-array(@array) {
# (it'll stop at the furthest operator in the current expression)
my @arrayplus3 = map(*+3, @array); # `*+3` is the same as `{ $_ + 3 }`
my @arrayplus3 = map(*+*+3, @array); # Same as `-> $a, $b { $a + $b + 3 }`
# also `sub ($a, $b) { $a + $b + 3 }`
say (*/2)(4); #=> 2
# Immediatly execute the function Whatever created.
say ((*+3)/5)(5); #=> 1.6
@ -496,7 +497,8 @@ say ((*+3)/5)(5); #=> 1.6
# But if you need to have more than one argument (`$_`)
# in a block (without wanting to resort to `-> {}`),
# you can also use the implicit argument syntax, `$^` :
map({ $^a + $^b + 3 }, @array); # same as the above
map({ $^a + $^b + 3 }, @array); # equivalent to following:
map(sub ($a, $b) { $a + $b + 3 }, @array); # (here with `sub`)
# Note : those are sorted lexicographically.
# `{ $^b / $^a }` is like `-> $a, $b { $b / $a }`
@ -1072,6 +1074,11 @@ my @list = 1, 3, 9 ... { $_ > 30 }; # (equivalent to the above)
my @fib = 1, 1, *+* ... *; # lazy infinite list of prime numbers,
# computed using a closure!
my @fib = 1, 1, -> $a, $b { $a + $b } ... *; # (equivalent to the above)
my @fib = 1, 1, { $^a + $^b } ... *; #(... also equivalent to the above)
# $a and $b will always take the previous values, meaning here
# they'll start with $a = 1 and $b = 1 (values we set by hand).
# then $a = 1 and $b = 2 (result from previous $a+$b), and so on.
say @fib[^10]; #=> 1 1 2 3 5 8 13 21 34 55
# (using a range as the index)
# Note : as for ranges, once reified, elements aren't re-calculated.