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|
/*
* This source code is released into the public domain.
*/
module;
#include <iostream>
#include <print>
#include <ranges>
#include <string>
#include <vector>
module nihil.cli;
namespace nihil {
command_tree_node::command_tree_node()
: m_this_word("")
, m_command(std::make_shared<command_node>(command_node("")))
{
}
command_tree_node::command_tree_node(command_tree_node *parent,
std::string_view this_word)
: m_parent(parent)
, m_this_word(this_word)
{
}
command_tree_node::command_tree_node(command_tree_node *parent,
std::string_view this_word,
std::shared_ptr<command_node> command)
: m_parent(parent)
, m_this_word(this_word)
, m_command(std::move(command))
{
}
auto command_tree_node::get_child(this command_tree_node const &self,
std::string_view child)
-> command_tree_node const *
{
if (auto it = self.m_children.find(std::string(child));
it != self.m_children.end())
return &it->second;
return nullptr;
}
auto command_tree_node::get_child(this command_tree_node &self,
std::string_view child)
-> command_tree_node *
{
if (auto it = self.m_children.find(std::string(child));
it != self.m_children.end())
return &it->second;
return nullptr;
}
auto command_tree_node::get_or_create_child(this command_tree_node &self,
std::string_view child)
-> command_tree_node *
{
// Return the existing child, if there is one.
if (auto ptr = self.get_child(child); ptr != nullptr)
return ptr;
// Insert a new child.
auto [it, ok] = self.m_children.emplace(
child,
command_tree_node(&self, child));
// Give the child a dummy command.
auto path = self.m_parent != nullptr
? std::format("{} {}", self.m_parent->path(), child)
: std::string(child);
it->second.m_command = std::make_shared<command_node>(path);
return &it->second;
}
auto command_tree_node::command(this command_tree_node const &self)
-> std::shared_ptr<command_node> const &
{
return self.m_command;
}
auto command_tree_node::command(this command_tree_node &self,
std::shared_ptr<command_node> command)
-> void
{
// TODO: Put this check back without tripping from the dummy command.
//if (self.m_command != nullptr)
// throw std::logic_error("duplicate command");
self.m_command = std::move(command);
}
auto command_tree_node::print_commands(this command_tree_node const &self)
-> void
{
auto prefix = std::string(self.path());
for (auto &&[name, node] : self.m_children) {
auto command = prefix.empty()
? name
: (prefix + ' ' + name);
std::print(std::cerr, " {}\n", command);
}
}
auto command_tree_node::path(this command_tree_node const &self)
-> std::string_view
{
return self.m_command->path();
}
auto command_tree::insert(this command_tree &self,
std::vector<std::string_view> const &path,
std::shared_ptr<command_node> command)
-> void
{
auto *this_node = &self.m_root_node;
// Find the node for this key.
for (auto &&this_word : path)
this_node = this_node->get_or_create_child(this_word);
// Set the new value.
this_node->command(std::move(command));
}
auto command_tree::find(this command_tree const &self, int &argc, char **&argv)
-> command_tree_node const *
{
auto *this_node = &self.m_root_node;
// Iterate until we don't find a child command, then return that node.
while (argv[0] != nullptr) {
auto *next_node = this_node->get_child(argv[0]);
if (next_node == nullptr)
return this_node;
this_node = next_node;
--argc;
++argv;
}
// We ran out of path without finding a valid command. Return this
// node; the caller will notice the missing command.
return this_node;
}
auto build_command_tree() -> command_tree
{
auto const &commands = get_registered_commands();
auto tree = command_tree();
for (auto &&command : commands) {
auto split_path = std::vector<std::string_view>(
std::from_range,
command->path()
| std::views::split(' ')
| std::views::transform([] (auto &&r) {
return std::string_view(r);
}));
// Throws std::logic_error on duplicates.
tree.insert(split_path, command);
}
return tree;
}
} // namespace nihil
|
