AK+Kernel: Unify Traits<T>::equals()'s argument order on different types

There was a small mishmash of argument order, as seen on the table:

                 | Traits<T>::equals(U, T) | Traits<T>::equals(T, U)
   ============= | ======================= | =======================
   uses equals() | HashMap                 | Vector, HashTable
defines equals() | *String[^1]             | ByteBuffer

[^1]: String, DeprecatedString, their Fly-type equivalents and KString.

This mostly meant that you couldn't use a StringView for finding a value
in Vector<String>.

I'm changing the order of arguments to make the trait type itself first
(`Traits<T>::equals(T, U)`), as I think it's more expected and makes us
more consistent with the rest of the functions that put the stored type
first (like StringUtils functions and binary_serach). I've also renamed
the variable name "other" in find functions to "entry" to give more
importance to the value.

With this change, each of the following lines will now compile
successfully:

    Vector<String>().contains_slow("WHF!"sv);
    HashTable<String>().contains("WHF!"sv);
    HashMap<ByteBuffer, int>().contains("WHF!"sv.bytes());
This commit is contained in:
Karol Kosek 2023-08-21 16:38:11 +02:00 committed by Andreas Kling
parent 5ff7448fee
commit e575ee4462
Notes: sideshowbarker 2024-07-17 08:38:37 +09:00
7 changed files with 26 additions and 16 deletions

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@ -26,6 +26,7 @@ template<typename TEndIterator, IteratorPairWith<TEndIterator> TIterator, typena
template<typename TEndIterator, IteratorPairWith<TEndIterator> TIterator, typename T>
[[nodiscard]] constexpr TIterator find(TIterator first, TEndIterator last, T const& value)
{
// FIXME: Use the iterator's trait type, and swap arguments in equals call.
return find_if(first, last, [&](auto const& v) { return Traits<T>::equals(value, v); });
}
@ -33,6 +34,7 @@ template<typename TEndIterator, IteratorPairWith<TEndIterator> TIterator, typena
[[nodiscard]] constexpr size_t find_index(TIterator first, TEndIterator last, T const& value)
requires(requires(TIterator it) { it.index(); })
{
// FIXME: Use the iterator's trait type, and swap arguments in equals call.
return find_if(first, last, [&](auto const& v) { return Traits<T>::equals(value, v); }).index();
}

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@ -98,7 +98,7 @@ public:
[[nodiscard]] IteratorType end() { return m_table.end(); }
[[nodiscard]] IteratorType find(K const& key)
{
return m_table.find(KeyTraits::hash(key), [&](auto& entry) { return KeyTraits::equals(key, entry.key); });
return m_table.find(KeyTraits::hash(key), [&](auto& entry) { return KeyTraits::equals(entry.key, key); });
}
template<typename TUnaryPredicate>
[[nodiscard]] IteratorType find(unsigned hash, TUnaryPredicate predicate)
@ -110,7 +110,7 @@ public:
[[nodiscard]] ConstIteratorType end() const { return m_table.end(); }
[[nodiscard]] ConstIteratorType find(K const& key) const
{
return m_table.find(KeyTraits::hash(key), [&](auto& entry) { return KeyTraits::equals(key, entry.key); });
return m_table.find(KeyTraits::hash(key), [&](auto& entry) { return KeyTraits::equals(entry.key, key); });
}
template<typename TUnaryPredicate>
[[nodiscard]] ConstIteratorType find(unsigned hash, TUnaryPredicate predicate) const
@ -121,13 +121,13 @@ public:
template<Concepts::HashCompatible<K> Key>
requires(IsSame<KeyTraits, Traits<K>>) [[nodiscard]] IteratorType find(Key const& key)
{
return m_table.find(Traits<Key>::hash(key), [&](auto& entry) { return Traits<K>::equals(key, entry.key); });
return m_table.find(Traits<Key>::hash(key), [&](auto& entry) { return Traits<K>::equals(entry.key, key); });
}
template<Concepts::HashCompatible<K> Key>
requires(IsSame<KeyTraits, Traits<K>>) [[nodiscard]] ConstIteratorType find(Key const& key) const
{
return m_table.find(Traits<Key>::hash(key), [&](auto& entry) { return Traits<K>::equals(key, entry.key); });
return m_table.find(Traits<Key>::hash(key), [&](auto& entry) { return Traits<K>::equals(entry.key, key); });
}
ErrorOr<void> try_ensure_capacity(size_t capacity) { return m_table.try_ensure_capacity(capacity); }

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@ -317,7 +317,7 @@ public:
[[nodiscard]] Iterator find(T const& value)
{
return find(TraitsForT::hash(value), [&](auto& other) { return TraitsForT::equals(value, other); });
return find(TraitsForT::hash(value), [&](auto& entry) { return TraitsForT::equals(entry, value); });
}
template<typename TUnaryPredicate>
@ -328,14 +328,14 @@ public:
[[nodiscard]] ConstIterator find(T const& value) const
{
return find(TraitsForT::hash(value), [&](auto& other) { return TraitsForT::equals(value, other); });
return find(TraitsForT::hash(value), [&](auto& entry) { return TraitsForT::equals(entry, value); });
}
// FIXME: Support for predicates, while guaranteeing that the predicate call
// does not call a non trivial constructor each time invoked
template<Concepts::HashCompatible<T> K>
requires(IsSame<TraitsForT, Traits<T>>) [[nodiscard]] Iterator find(K const& value)
{
return find(Traits<K>::hash(value), [&](auto& other) { return Traits<T>::equals(other, value); });
return find(Traits<K>::hash(value), [&](auto& entry) { return Traits<T>::equals(entry, value); });
}
template<Concepts::HashCompatible<T> K, typename TUnaryPredicate>
@ -347,7 +347,7 @@ public:
template<Concepts::HashCompatible<T> K>
requires(IsSame<TraitsForT, Traits<T>>) [[nodiscard]] ConstIterator find(K const& value) const
{
return find(Traits<K>::hash(value), [&](auto& other) { return Traits<T>::equals(other, value); });
return find(Traits<K>::hash(value), [&](auto& entry) { return Traits<T>::equals(entry, value); });
}
template<Concepts::HashCompatible<T> K, typename TUnaryPredicate>

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@ -224,12 +224,12 @@ public:
ConstIterator find(T const& value) const
{
return find_if([&](auto& other) { return Traits<T>::equals(value, other); });
return find_if([&](auto& entry) { return Traits<T>::equals(entry, value); });
}
Iterator find(T const& value)
{
return find_if([&](auto& other) { return Traits<T>::equals(value, other); });
return find_if([&](auto& entry) { return Traits<T>::equals(entry, value); });
}
template<typename U = T>

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@ -22,7 +22,7 @@ struct GenericTraits {
static constexpr bool is_trivially_serializable() { return false; }
static constexpr bool equals(T const& a, T const& b) { return a == b; }
template<Concepts::HashCompatible<T> U>
static bool equals(U const& a, T const& b) { return a == b; }
static bool equals(T const& self, U const& other) { return self == other; }
};
template<typename T>

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@ -91,7 +91,7 @@ struct Traits<NonnullOwnPtr<Kernel::KString>> : public GenericTraits<NonnullOwnP
using ConstPeekType = Kernel::KString const*;
static unsigned hash(NonnullOwnPtr<Kernel::KString> const& p) { return string_hash(p->characters(), p->length()); }
static bool equals(NonnullOwnPtr<Kernel::KString> const& a, NonnullOwnPtr<Kernel::KString> const& b) { return a->view() == b->view(); }
static bool equals(StringView a, NonnullOwnPtr<Kernel::KString> const& b) { return a == b->view(); }
static bool equals(NonnullOwnPtr<Kernel::KString> const& a, StringView b) { return a->view() == b; }
};
template<>
@ -113,11 +113,11 @@ struct Traits<OwnPtr<Kernel::KString>> : public GenericTraits<OwnPtr<Kernel::KSt
return a->view() == b->view();
}
static bool equals(StringView a, OwnPtr<Kernel::KString> const& b)
static bool equals(OwnPtr<Kernel::KString> const& a, StringView b)
{
if (!b)
return a.is_null();
return a == b->view();
if (!a)
return b.is_null();
return a->view() == b;
}
};

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@ -9,6 +9,7 @@
#include <AK/DeprecatedString.h>
#include <AK/OwnPtr.h>
#include <AK/ReverseIterator.h>
#include <AK/String.h>
#include <AK/Vector.h>
TEST_CASE(construct)
@ -431,6 +432,13 @@ TEST_CASE(should_find_predicate_index)
EXPECT(!v.find_first_index_if([](auto const v) { return v == 123; }).has_value());
}
TEST_CASE(should_find_using_a_hashcompatible_value)
{
// Tests whether a hash-compatible value can be used to compare (Strings cannot be impliticly constructed from a StringView.)
Vector v { "hello!"_string };
EXPECT(v.contains_slow("hello!"sv));
}
TEST_CASE(should_contain_start)
{
// Tests whether value is found if at the start of the range.