wroclaw-git-backups/nix
1
0
Fork 0
mirror of https://github.com/NixOS/nix synced 2025-06-28 17:51:15 +02:00
Code Activity

nix: Implement basic bash completion

Browse source
This commit is contained in:
Eelco Dolstra 2020-05-10 20:32:21 +02:00
parent 14a3a62bfc
commit 91ddee6bf0
9 changed files with 95 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

55
src/libutil/args.cc
View file

@ -13,6 +13,19 @@ void Args::addFlag(Flag && flag_)
if (flag->shortName) shortFlags[flag->shortName] = flag;
}
std::shared_ptr<std::set<std::string>> completions;
std::string completionMarker = "___COMPLETE___";
std::optional<std::string> needsCompletion(std::string_view s)
{
if (!completions) return {};
auto i = s.find(completionMarker);
if (i != std::string::npos)
return std::string(s.begin(), i);
return {};
}
void Args::parseCmdline(const Strings & _cmdline)
{
Strings pendingArgs;
@ -20,6 +33,13 @@ void Args::parseCmdline(const Strings & _cmdline)
Strings cmdline(_cmdline);
if (auto s = getEnv("NIX_GET_COMPLETIONS")) {
size_t n = std::stoi(*s);
assert(n > 0 && n <= cmdline.size());
*std::next(cmdline.begin(), n - 1) += completionMarker;
completions = std::make_shared<decltype(completions)::element_type>();
}
for (auto pos = cmdline.begin(); pos != cmdline.end(); ) {
auto arg = *pos;
@ -99,18 +119,32 @@ bool Args::processFlag(Strings::iterator & pos, Strings::iterator end)
auto process = [&](const std::string & name, const Flag & flag) -> bool {
++pos;
std::vector<std::string> args;
bool anyNeedsCompletion = false;
for (size_t n = 0 ; n < flag.handler.arity; ++n) {
if (pos == end) {
if (flag.handler.arity == ArityAny) break;
throw UsageError("flag '%s' requires %d argument(s)", name, flag.handler.arity);
if (anyNeedsCompletion)
args.push_back("");
else
throw UsageError("flag '%s' requires %d argument(s)", name, flag.handler.arity);
} else {
if (needsCompletion(*pos))
anyNeedsCompletion = true;
args.push_back(*pos++);
}
args.push_back(*pos++);
}
flag.handler.fun(std::move(args));
return true;
};
if (string(*pos, 0, 2) == "--") {
if (auto prefix = needsCompletion(*pos)) {
for (auto & [name, flag] : longFlags) {
if (!hiddenCategories.count(flag->category)
&& hasPrefix(name, std::string(*prefix, 2)))
completions->insert("--" + name);
}
}
auto i = longFlags.find(string(*pos, 2));
if (i == longFlags.end()) return false;
return process("--" + i->first, *i->second);
@ -123,6 +157,14 @@ bool Args::processFlag(Strings::iterator & pos, Strings::iterator end)
return process(std::string("-") + c, *i->second);
}
if (auto prefix = needsCompletion(*pos)) {
if (prefix == "-") {
completions->insert("--");
for (auto & [flag, _] : shortFlags)
completions->insert(std::string("-") + flag);
}
}
return false;
}
@ -161,6 +203,10 @@ Args::Flag Args::Flag::mkHashTypeFlag(std::string && longName, HashType * ht)
.description = "hash algorithm ('md5', 'sha1', 'sha256', or 'sha512')",
.labels = {"hash-algo"},
.handler = {[ht](std::string s) {
if (auto prefix = needsCompletion(s))
for (auto & type : hashTypes)
if (hasPrefix(type, *prefix))
completions->insert(type);
*ht = parseHashType(s);
if (*ht == htUnknown)
throw UsageError("unknown hash type '%1%'", s);
@ -217,6 +263,11 @@ MultiCommand::MultiCommand(const Commands & commands)
{
expectedArgs.push_back(ExpectedArg{"command", 1, true, [=](std::vector<std::string> ss) {
assert(!command);
if (auto prefix = needsCompletion(ss[0])) {
for (auto & [name, command] : commands)
if (hasPrefix(name, *prefix))
completions->insert(name);
}
auto i = commands.find(ss[0]);
if (i == commands.end())
throw UsageError("'%s' is not a recognised command", ss[0]);