lix/src/nix/eval.cc

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#include "command.hh"
#include "common-args.hh"
#include "shared.hh"
#include "store-api.hh"
#include "eval.hh"
#include "json.hh"
#include "value-to-json.hh"
using namespace nix;
2017-04-25 10:06:32 +00:00
struct CmdEval : MixJSON, InstallablesCommand
{
bool raw = false;
CmdEval()
{
mkFlag(0, "raw", "print strings unquoted", &raw);
}
std::string name() override
{
return "eval";
}
std::string description() override
{
return "evaluate a Nix expression";
}
void run(ref<Store> store) override
{
if (raw && json)
throw UsageError("--raw and --json are mutually exclusive");
auto state = getEvalState();
auto jsonOut = json ? std::make_unique<JSONList>(std::cout) : nullptr;
for (auto & i : installables) {
auto v = i->toValue(*state);
if (raw) {
std::cout << state->forceString(*v);
} else if (json) {
PathSet context;
auto jsonElem = jsonOut->placeholder();
printValueAsJSON(*state, true, *v, jsonElem, context);
} else {
state->forceValueDeep(*v);
std::cout << *v << "\n";
}
}
}
};
static RegisterCommand r1(make_ref<CmdEval>());