NAME

Array::Sorted::Util - Raku utilities for (native) sorted arrays

SYNOPSIS

use Array::Sorted::Util;  # imports finds, inserts, deletes

my @a;
inserts(@a,$_) for <d c f e g h a b j i>;
say @a;               # [a b c d e f g h i j]

.say with finds(@a,"h");    # 7
.say with finds(@a,"z");    # (no output)

say deletes(@a,"e");  # e
say @a;               # [a b c d f g h i j]

DESCRIPTION

Array::Sorted::Util exports a set of subroutines that create and manipulate sorted arrays.

SUBROUTINES

inserts

my @a;
my $pos = inserts(@a, "foo", :cmp(&[coll]));

inserts(@a, "foo");  # use infix:<cmp> by default

my @b;
my @c;
inserts(@b, 'foo', @c, 'bar');  # multiple associated lists

my @d = <a c e g i>;
my $pos = finds(@d,"d");
if $pos {
    say "Found at $pos";
}
else {
    inserts(@d,"d",:$pos);
}
say @d;  # (a c d e g i)

Insert the given object (the second argument) into the correct location in the given array (the first argument). Takes a named argument cmp to indicate the logic that should be used to determine order (defaults to infix:<cmp>). Additionally takes array, object arguments to insert the given object in the associated array at the same location. Returns the position at which the object(s) were actually inserted.

Can also take an optional named argument pos from a previously unsuccessful call to finds as a shortcut to prevent needing to search for the object again.

finds

my @a = <a b c d e f g h i j>;
.say with finds(@a, "h");   # 7, use infix:<cmp> by default
say "could not be found" without finds(@a, "z", :cmp(&[coll]));

Attempt to find the given object (the second argument) in the given sorted array (the first argument). Takes a named argument cmp to indicate the logic that should be used to determine order (defaults to infix:<cmp>). Returns a special undefined value if the object could not be found.

nexts

my @a = <a b c d e f g h i j>;
say nexts(@a, "g");  # h
say nexts(@a, "j");  # Nil

Return the object after the given object (the second argument) in the given sorted array (the first argument). Takes a named argument cmp to indicate the logic that should be used to determine order (defaults to infix:<cmp>). Returns Nil if no object could be found.

prevs

my @a = <a b c d e f g h i j>;
say prevs(@a, "g");  # f
say prevs(@a, "a");  # Nil

Return the object before the given object (the second argument) in the given sorted array (the first argument). Takes a named argument cmp to indicate the logic that should be used to determine order (defaults to infix:<cmp>). Returns Nil if no object could be found.

deletes

my @a = <a b c d e f g h i j>;
say deletes(@a, "e");                 # e, use &infix:<cmp> by default
say deletes(@a, "z", :cmp(&[coll]));  # Nil

Attempt to remove the given object (the second argument) from the given sorted array (the first argument). Takes a named argument cmp to indicate the logic that should be used to determine order (defaults to infix:<cmp>). Additionally takes array arguments to delete elements in the associated array at the same location. Returns the value of the primary removed object.

INSPIRATION

The inspiration for these names is from the TUTOR Programming Language, which had finds, inserts and deletes commands.

See https://files.eric.ed.gov/fulltext/ED208879.pdf for more information (pages C16 and C17).

AUTHOR

Elizabeth Mattijsen [email protected]

Source can be located at: https://github.com/lizmat/Array-Sorted-Util . Comments and Pull Requests are welcome.

COPYRIGHT AND LICENSE

Copyright 2021 Elizabeth Mattijsen

This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.