lix/src/libexpr/primops/fromTOML.cc
pennae 41d70a2fc8 return string_views from forceString*
once a string has been forced we already have dynamic storage allocated for it,
so we can easily reuse that storage instead of copying.
2022-01-27 17:15:43 +01:00

84 lines
2.5 KiB
C++

#include "primops.hh"
#include "eval-inline.hh"
#include "../../toml11/toml.hpp"
namespace nix {
static void prim_fromTOML(EvalState & state, const Pos & pos, Value * * args, Value & val)
{
auto toml = state.forceStringNoCtx(*args[0], pos);
std::istringstream tomlStream(string{toml});
std::function<void(Value &, toml::value)> visit;
visit = [&](Value & v, toml::value t) {
switch(t.type())
{
case toml::value_t::table:
{
auto table = toml::get<toml::table>(t);
size_t size = 0;
for (auto & i : table) { (void) i; size++; }
auto attrs = state.buildBindings(size);
for(auto & elem : table)
visit(attrs.alloc(elem.first), elem.second);
v.mkAttrs(attrs);
}
break;;
case toml::value_t::array:
{
auto array = toml::get<std::vector<toml::value>>(t);
size_t size = array.size();
state.mkList(v, size);
for (size_t i = 0; i < size; ++i)
visit(*(v.listElems()[i] = state.allocValue()), array[i]);
}
break;;
case toml::value_t::boolean:
v.mkBool(toml::get<bool>(t));
break;;
case toml::value_t::integer:
v.mkInt(toml::get<int64_t>(t));
break;;
case toml::value_t::floating:
v.mkFloat(toml::get<NixFloat>(t));
break;;
case toml::value_t::string:
v.mkString(toml::get<std::string>(t));
break;;
case toml::value_t::local_datetime:
case toml::value_t::offset_datetime:
case toml::value_t::local_date:
case toml::value_t::local_time:
// We fail since Nix doesn't have date and time types
throw std::runtime_error("Dates and times are not supported");
break;;
case toml::value_t::empty:
v.mkNull();
break;;
}
};
try {
visit(val, toml::parse(tomlStream, "fromTOML" /* the "filename" */));
} catch (std::exception & e) { // TODO: toml::syntax_error
throw EvalError({
.msg = hintfmt("while parsing a TOML string: %s", e.what()),
.errPos = pos
});
}
}
static RegisterPrimOp primop_fromTOML("fromTOML", 1, prim_fromTOML);
}