diff options
| author | Burdette Lamar <[email protected]> | 2025-02-10 13:32:25 -0600 |
|---|---|---|
| committer | GitHub <[email protected]> | 2025-02-10 14:32:25 -0500 |
| commit | b4bf3ed13036a01c2082bd279e6faecd5d51a740 (patch) | |
| tree | e45a67ae441d67c66ce4cd364ba7fb4c0acaa950 /doc | |
| parent | 7fd589c7fc26b0494990134d6bef699c92a9336c (diff) | |
[DOC] Adds section "Hash Inclusion" (#12634)
Notes
Notes:
Merged-By: peterzhu2118 <[email protected]>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/hash_inclusion.rdoc | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/doc/hash_inclusion.rdoc b/doc/hash_inclusion.rdoc new file mode 100644 index 0000000000..05c2b0932a --- /dev/null +++ b/doc/hash_inclusion.rdoc @@ -0,0 +1,31 @@ +== \Hash Inclusion + +A hash is set-like in that it cannot have duplicate entries +(or even duplicate keys). +\Hash inclusion can therefore based on the idea of +{subset and superset}[https://en.wikipedia.org/wiki/Subset]. + +Two hashes may be tested for inclusion, +based on comparisons of their entries. + +An entry <tt>h0[k0]</tt> in one hash +is equal to an entry <tt>h1[k1]</tt> in another hash +if and only if the two keys are equal (<tt>k0 == k1</tt>) +and their two values are equal (<tt>h0[k0] == h1[h1]</tt>). + +A hash may be a subset or a superset of another hash: + +- Subset (included in or equal to another): + + - \Hash +h0+ is a _subset_ of hash +h1+ (see Hash#<=) + if each entry in +h0+ is equal to an entry in +h1+. + - Further, +h0+ is a <i>proper subset</i> of +h1+ (see Hash#<) + if +h1+ is larger than +h0+. + +- Superset (including or equal to another): + + - \Hash +h0+ is a _superset_ of hash +h1+ (see Hash#>=) + if each entry in +h1+ is equal to an entry in +h0+. + - Further, +h0+ is a <i>proper superset</i> of +h1+ (see Hash#>) + if +h0+ is larger than +h1+. + |