Reqrite project as BEd specific.

2026-08-13 16:17:32 +01:00
parent cc5d475ab8
commit cd13557e15
46 changed files with 1115 additions and 1026 deletions
@@ -0,0 +1,246 @@
+#pragma once
+
+#include "pch.h"
+
+namespace bed::internal::trie {
+template <typename T = void>
+struct Trie {
+  using V = std::conditional_t<std::is_void_v<T>, std::monostate, T>;
+
+  struct Node {
+    std::string edge;
+    std::optional<V> value{};
+    std::vector<Node *> children;
+    Node(std::string e = {}) : edge(std::move(e)) {}
+    ~Node() {
+      for (auto *c : children)
+        delete c;
+    };
+  } root;
+
+  bool case_sensitive;
+
+  Trie(bool cs = true) : case_sensitive(cs) {}
+
+  void insert(std::string_view key)
+    requires std::is_void_v<T>
+  {
+    _insert(key, std::monostate{});
+  }
+
+  void insert(std::string_view key, V el)
+    requires(!std::is_void_v<T>)
+  {
+    _insert(key, std::move(el));
+  }
+
+  void _insert(std::string_view key, V &&el) {
+    Node *current = &root;
+    uint64_t pos = 0;
+    while (pos < key.size()) {
+      Node *child = find_child(*current, key[pos]);
+      if (!child) {
+        auto *node = new Node(std::string(key.substr(pos)));
+        node->value = std::move(el);
+        current->children.push_back(node);
+        return;
+      }
+      const auto common = common_prefix(child->edge, key.substr(pos));
+      if (common == child->edge.size()) {
+        pos += common;
+        current = child;
+        continue;
+      }
+      auto *split = new Node(child->edge.substr(0, common));
+      child->edge.erase(0, common);
+      split->children.push_back(child);
+      current->children.erase(
+        std::find(current->children.begin(), current->children.end(), child)
+      );
+      current->children.push_back(split);
+      pos += common;
+      if (pos == key.size()) {
+        split->value = std::move(el);
+        return;
+      }
+      auto *node = new Node(std::string(key.substr(pos)));
+      node->value = std::move(el);
+      split->children.push_back(node);
+      return;
+    }
+    current->value = std::move(el);
+  }
+
+  void remove(std::string_view key) {
+    _remove(root, key, 0);
+  }
+
+  bool _remove(Node &node, std::string_view key, uint64_t pos) {
+    if (pos == key.size()) {
+      if (!node.value)
+        return false;
+      node.value.reset();
+      return true;
+    }
+    Node *child = find_child(node, key[pos]);
+    if (!child)
+      return false;
+    const auto remaining = key.substr(pos);
+    const auto common = common_prefix(child->edge, remaining);
+    if (common != child->edge.size())
+      return false;
+    const auto child_pos = pos + common;
+    if (!_remove(*child, key, child_pos))
+      return false;
+    if (!child->value && child->children.empty()) {
+      auto it = std::find(
+        node.children.begin(),
+        node.children.end(),
+        child
+      );
+      node.children.erase(it);
+      delete child;
+      return true;
+    }
+    if (!child->value && child->children.size() == 1) {
+      Node *grandchild = child->children.front();
+      child->edge += grandchild->edge;
+      child->value = std::move(grandchild->value);
+      child->children = std::move(grandchild->children);
+      grandchild->children.clear();
+      delete grandchild;
+    }
+    return true;
+  }
+
+  std::vector<std::string> search(std::string_view prefix) {
+    std::vector<std::string> result;
+    Node *current = &root;
+    std::string key;
+    uint64_t pos = 0;
+    while (pos < prefix.size()) {
+      Node *child = find_child(*current, prefix[pos]);
+      if (!child)
+        return result;
+      const auto remaining = prefix.substr(pos);
+      const auto common = common_prefix(child->edge, remaining);
+      if (common == 0)
+        return result;
+      if (common < child->edge.size()) {
+        if (common == remaining.size()) {
+          key += child->edge;
+          collect(*child, key, result);
+          return result;
+        }
+        return result;
+      }
+      key += child->edge;
+      pos += common;
+      current = child;
+    }
+    collect(*current, key, result);
+    return result;
+  }
+
+  static void collect(
+    const Node &node,
+    std::string &key,
+    std::vector<std::string> &result
+  ) {
+    if (node.value)
+      result.push_back(key);
+    for (auto *child : node.children) {
+      const auto old_size = key.size();
+      key += child->edge;
+      collect(*child, key, result);
+      key.resize(old_size);
+    }
+  }
+
+  uint64_t longest_match(std::string_view input) {
+    Node *current = &root;
+    uint64_t pos = 0;
+    uint64_t longest = 0;
+    if (current->value)
+      longest = 0;
+    while (pos < input.size()) {
+      Node *child = find_child(*current, input[pos]);
+      if (!child)
+        break;
+      const auto remaining = input.substr(pos);
+      const auto common = common_prefix(child->edge, remaining);
+      if (common != child->edge.size())
+        break;
+      pos += common;
+      current = child;
+      if (current->value)
+        longest = pos;
+    }
+    return longest;
+  }
+
+  bool matches(std::string_view key)
+    requires(std::is_void_v<T>)
+  {
+    Node *current = &root;
+    uint64_t pos = 0;
+    while (pos < key.size()) {
+      Node *child = find_child(*current, key[pos]);
+      if (!child)
+        return false;
+      const auto remaining = key.substr(pos);
+      const auto common = common_prefix(child->edge, remaining);
+      if (common != child->edge.size())
+        return false;
+      pos += common;
+      current = child;
+    }
+    return current->value.has_value();
+  }
+
+  std::optional<V> get(std::string_view key)
+    requires(!std::is_void_v<T>)
+  {
+    Node *current = &root;
+    uint64_t pos = 0;
+    while (pos < key.size()) {
+      Node *child = find_child(*current, key[pos]);
+      if (!child)
+        return std::nullopt;
+      const auto remaining = key.substr(pos);
+      const auto common = common_prefix(child->edge, remaining);
+      if (common != child->edge.size())
+        return std::nullopt;
+      pos += common;
+      current = child;
+    }
+    if (!current->value)
+      return std::nullopt;
+    return *current->value;
+  }
+
+  bool equal_char(char a, char b) const {
+    if (case_sensitive)
+      return a == b;
+    return std::tolower((unsigned char)a) == std::tolower((unsigned char)b);
+  }
+
+  uint64_t common_prefix(
+    std::string_view a,
+    std::string_view b
+  ) {
+    const auto n = std::min(a.size(), b.size());
+    uint64_t i = 0;
+    while (i < n && equal_char(a[i], b[i]))
+      ++i;
+    return i;
+  }
+
+  Node *find_child(Node &node, char first) {
+    for (auto *child : node.children)
+      if (equal_char(child->edge.front(), first))
+        return child;
+    return nullptr;
+  }
+};
+} // namespace bed::internal::trie