Documentation for routine
squish assembled from the following types:
sub squish( +values, |c)
Returns a sequence of values from the invocant/argument list where runs of one or more values are replaced with only the first instance. Like
squish uses the semantics of the === operator to decide whether two objects are the same. Unlike
unique, this function only removes adjacent duplicates; identical values further apart are still kept. The order of the original list is preserved even as duplicates are removed.
say <a a b b b c c>.squish; # OUTPUT: «(a b c)␤»say <a b b c c b a>.squish; # OUTPUT: «(a b c b a)␤»
:as parameter, just like with
unique, allows values to be temporarily transformed before comparison.
:with parameter is used to set an appropriate comparison operator:
say [42, "42"].squish; # OUTPUT: «(42 42)␤»# Note that the second item in the result is still Strsay [42, "42"].squish(with => :<eq>); # OUTPUT: «(42)␤»# The resulting item is Int
multi method squish( :!, : = &[===] )multi method squish( : = &[===] )
.repeated, returns the sequence of first elements of contiguous sequences of equal elements, after normalization by the function
:as, if present, and using as an equality operator the
:with argument or
=== by default.
"aabbccddaa".comb.squish.say; # OUTPUT: «(a b c d a)␤»"aABbccdDaa".comb.squish( :as() ).say; # OUTPUT: «(a B c d a)␤»(3+2i,3+3i,4+0i).squish( as => *.re, with => &[==]).put; #OUTPUT: «3+2i 4+0i␤»
As shown in the last example, a sequence can contain a single element. See
squish for additional
method squish(Supply: :, : --> Supply)
Creates a supply that only provides unique values, as defined by the optional
:with parameters (same as with List.squish).