From f6ad4dcef54c5ce997a4bad5a6d86de229015700 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Tue, 16 Apr 2024 21:25:22 +0200 Subject: Adding upstream version 1.22.1. Signed-off-by: Daniel Baumann --- src/cmd/compile/internal/syntax/testdata/map.go | 112 ++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 src/cmd/compile/internal/syntax/testdata/map.go (limited to 'src/cmd/compile/internal/syntax/testdata/map.go') diff --git a/src/cmd/compile/internal/syntax/testdata/map.go b/src/cmd/compile/internal/syntax/testdata/map.go new file mode 100644 index 0000000..a508d21 --- /dev/null +++ b/src/cmd/compile/internal/syntax/testdata/map.go @@ -0,0 +1,112 @@ +// Copyright 2019 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package orderedmap provides an ordered map, implemented as a binary tree. +package orderedmap + +import "chans" + +// Map is an ordered map. +type Map[K, V any] struct { + root *node[K, V] + compare func(K, K) int +} + +// node is the type of a node in the binary tree. +type node[K, V any] struct { + key K + val V + left, right *node[K, V] +} + +// New returns a new map. +func New[K, V any](compare func(K, K) int) *Map[K, V] { + return &Map[K, V]{compare: compare} +} + +// find looks up key in the map, and returns either a pointer +// to the node holding key, or a pointer to the location where +// such a node would go. +func (m *Map[K, V]) find(key K) **node[K, V] { + pn := &m.root + for *pn != nil { + switch cmp := m.compare(key, (*pn).key); { + case cmp < 0: + pn = &(*pn).left + case cmp > 0: + pn = &(*pn).right + default: + return pn + } + } + return pn +} + +// Insert inserts a new key/value into the map. +// If the key is already present, the value is replaced. +// Returns true if this is a new key, false if already present. +func (m *Map[K, V]) Insert(key K, val V) bool { + pn := m.find(key) + if *pn != nil { + (*pn).val = val + return false + } + *pn = &node[K, V]{key: key, val: val} + return true +} + +// Find returns the value associated with a key, or zero if not present. +// The found result reports whether the key was found. +func (m *Map[K, V]) Find(key K) (V, bool) { + pn := m.find(key) + if *pn == nil { + var zero V // see the discussion of zero values, above + return zero, false + } + return (*pn).val, true +} + +// keyValue is a pair of key and value used when iterating. +type keyValue[K, V any] struct { + key K + val V +} + +// InOrder returns an iterator that does an in-order traversal of the map. +func (m *Map[K, V]) InOrder() *Iterator[K, V] { + sender, receiver := chans.Ranger[keyValue[K, V]]() + var f func(*node[K, V]) bool + f = func(n *node[K, V]) bool { + if n == nil { + return true + } + // Stop sending values if sender.Send returns false, + // meaning that nothing is listening at the receiver end. + return f(n.left) && + sender.Send(keyValue[K, V]{n.key, n.val}) && + f(n.right) + } + go func() { + f(m.root) + sender.Close() + }() + return &Iterator[K, V]{receiver} +} + +// Iterator is used to iterate over the map. +type Iterator[K, V any] struct { + r *chans.Receiver[keyValue[K, V]] +} + +// Next returns the next key and value pair, and a boolean indicating +// whether they are valid or whether we have reached the end. +func (it *Iterator[K, V]) Next() (K, V, bool) { + keyval, ok := it.r.Next() + if !ok { + var zerok K + var zerov V + return zerok, zerov, false + } + return keyval.key, keyval.val, true +} -- cgit v1.2.3