hashmap

https://bugs.ruby-lang.org/issues/7793

map_values(&block)

Yields: value

Returns a new hash which is a copy of the current hash but each value is replaced by the result of running it through block.

{'a'=>1, 'b'=>2}.map_values { |v| v*2 } #=> {'a'=>2, 'b'=>4}
{'a'=>1, 'b'=>2}.map_values { "cat" }   #=> {'a'=>"cat", 'b'=>"cat"}

If no block is given, an Enumerator is returned instead.

map_keys(&block)

Yields: key

Returns a new hash which is a copy of the current hash but each key is replaced by the result of running it through block.

If block returns duplicate keys, they will be overwritten in the resulting hash.

{'a'=>1, 'b'=>2}.map_keys { |k| k*2 } #=> {'aa'=>1, 'bb'=>2}
{'a'=>1, 'b'=>2}.map_keys { "cat" }   #=> {'cat'=>2}

If no block is given, an Enumerator is returned instead.

map_pairs(&block)

Yields: key, value

Returns a new hash which is a copy of the current hash but each key-value pair is replaced by the result of running it through block.

If block returns duplicate keys, they will be overwritten in the resulting hash.

{'a'=>1, 'b'=>2}.map_pairs { |k,v| [k*2, v+1] } #=> {'aa'=>2, 'bb'=>3}
{'a'=>1, 'b'=>2}.map_pairs { ["cat","dog"] }   #=> {'cat'=>'dog'}

If no block is given, an Enumerator is returned instead.

Contributing

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Contributor Code of Conduct

This repository is subject to a Contributor Code of Conduct adapted from the Contributor Covenant, version 3.0, available at https://www.contributor-covenant.org/version/3/0/

Licence

This project is licensed under the ISC licence. See LICENSE for details

Copyright (c) 2013-2016, Matthew Kerwin <matthew@kerwin.net.au>

Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

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WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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