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nix/src/libcmd/repl.cc
2025-06-12 19:42:50 +00:00

937 lines
30 KiB
C++

#include <iostream>
#include <cstdlib>
#include <cstring>
#include "nix/util/error.hh"
#include "nix/cmd/repl-interacter.hh"
#include "nix/cmd/repl.hh"
#include "nix/util/ansicolor.hh"
#include "nix/main/shared.hh"
#include "nix/expr/eval.hh"
#include "nix/expr/eval-settings.hh"
#include "nix/expr/attr-path.hh"
#include "nix/util/signals.hh"
#include "nix/store/store-open.hh"
#include "nix/store/log-store.hh"
#include "nix/cmd/common-eval-args.hh"
#include "nix/expr/get-drvs.hh"
#include "nix/store/derivations.hh"
#include "nix/store/globals.hh"
#include "nix/flake/flake.hh"
#include "nix/flake/lockfile.hh"
#include "nix/util/users.hh"
#include "nix/cmd/editor-for.hh"
#include "nix/util/finally.hh"
#include "nix/cmd/markdown.hh"
#include "nix/store/local-fs-store.hh"
#include "nix/expr/print.hh"
#include "nix/util/ref.hh"
#include "nix/expr/value.hh"
#include "nix/util/strings.hh"
namespace nix {
/**
* Returned by `NixRepl::processLine`.
*/
enum class ProcessLineResult {
/**
* The user exited with `:quit`. The REPL should exit. The surrounding
* program or evaluation (e.g., if the REPL was acting as the debugger)
* should also exit.
*/
Quit,
/**
* The user exited with `:continue`. The REPL should exit, but the program
* should continue running.
*/
Continue,
/**
* The user did not exit. The REPL should request another line of input.
*/
PromptAgain,
};
struct NixRepl
: AbstractNixRepl
, detail::ReplCompleterMixin
, gc
{
size_t debugTraceIndex;
// Arguments passed to :load, saved so they can be reloaded with :reload
Strings loadedFiles;
// Arguments passed to :load-flake, saved so they can be reloaded with :reload
Strings loadedFlakes;
std::function<AnnotatedValues()> getValues;
const static int envSize = 32768;
std::shared_ptr<StaticEnv> staticEnv;
Value lastLoaded;
Env * env;
int displ;
StringSet varNames;
RunNix * runNixPtr;
void runNix(Path program, const Strings & args, const std::optional<std::string> & input = {});
std::unique_ptr<ReplInteracter> interacter;
NixRepl(const LookupPath & lookupPath, nix::ref<Store> store,ref<EvalState> state,
std::function<AnnotatedValues()> getValues, RunNix * runNix);
virtual ~NixRepl() = default;
ReplExitStatus mainLoop() override;
void initEnv() override;
virtual StringSet completePrefix(const std::string & prefix) override;
StorePath getDerivationPath(Value & v);
ProcessLineResult processLine(std::string line);
void loadFile(const Path & path);
void loadFlake(const std::string & flakeRef);
void loadFiles();
void loadFlakes();
void reloadFilesAndFlakes();
void showLastLoaded();
void addAttrsToScope(Value & attrs);
void addVarToScope(const Symbol name, Value & v);
Expr * parseString(std::string s);
void evalString(std::string s, Value & v);
void loadDebugTraceEnv(DebugTrace & dt);
void printValue(std::ostream & str,
Value & v,
unsigned int maxDepth = std::numeric_limits<unsigned int>::max())
{
// Hide the progress bar during printing because it might interfere
auto suspension = logger->suspend();
::nix::printValue(*state, str, v, PrintOptions {
.ansiColors = true,
.force = true,
.derivationPaths = true,
.maxDepth = maxDepth,
.prettyIndent = 2,
.errors = ErrorPrintBehavior::ThrowTopLevel,
});
}
};
std::string removeWhitespace(std::string s)
{
s = chomp(s);
size_t n = s.find_first_not_of(" \n\r\t");
if (n != std::string::npos) s = std::string(s, n);
return s;
}
NixRepl::NixRepl(const LookupPath & lookupPath, nix::ref<Store> store, ref<EvalState> state,
std::function<NixRepl::AnnotatedValues()> getValues, RunNix * runNix)
: AbstractNixRepl(state)
, debugTraceIndex(0)
, getValues(getValues)
, staticEnv(new StaticEnv(nullptr, state->staticBaseEnv))
, runNixPtr{runNix}
, interacter(make_unique<ReadlineLikeInteracter>(getDataDir() + "/repl-history"))
{
}
static std::ostream & showDebugTrace(std::ostream & out, const PosTable & positions, const DebugTrace & dt)
{
if (dt.isError)
out << ANSI_RED "error: " << ANSI_NORMAL;
out << dt.hint.str() << "\n";
auto pos = dt.getPos(positions);
if (pos) {
out << pos;
if (auto loc = pos.getCodeLines()) {
out << "\n";
printCodeLines(out, "", pos, *loc);
out << "\n";
}
}
return out;
}
MakeError(IncompleteReplExpr, ParseError);
static bool isFirstRepl = true;
ReplExitStatus NixRepl::mainLoop()
{
if (isFirstRepl) {
std::string_view debuggerNotice = "";
if (state->debugRepl) {
debuggerNotice = " debugger";
}
notice("Nix %1%%2%\nType :? for help.", nixVersion, debuggerNotice);
}
isFirstRepl = false;
loadFiles();
auto _guard = interacter->init(static_cast<detail::ReplCompleterMixin *>(this));
std::string input;
while (true) {
// Hide the progress bar while waiting for user input, so that it won't interfere.
{
auto suspension = logger->suspend();
// When continuing input from previous lines, don't print a prompt, just align to the same
// number of chars as the prompt.
if (!interacter->getLine(input, input.empty() ? ReplPromptType::ReplPrompt : ReplPromptType::ContinuationPrompt)) {
// Ctrl-D should exit the debugger.
state->debugStop = false;
logger->cout("");
// TODO: Should Ctrl-D exit just the current debugger session or
// the entire program?
return ReplExitStatus::QuitAll;
}
// `suspension` resumes the logger
}
try {
switch (processLine(input)) {
case ProcessLineResult::Quit:
return ReplExitStatus::QuitAll;
case ProcessLineResult::Continue:
return ReplExitStatus::Continue;
case ProcessLineResult::PromptAgain:
break;
default:
unreachable();
}
} catch (IncompleteReplExpr &) {
continue;
} catch (Error & e) {
printMsg(lvlError, e.msg());
} catch (Interrupted & e) {
printMsg(lvlError, e.msg());
}
// We handled the current input fully, so we should clear it
// and read brand new input.
input.clear();
std::cout << std::endl;
}
}
StringSet NixRepl::completePrefix(const std::string & prefix)
{
StringSet completions;
size_t start = prefix.find_last_of(" \n\r\t(){}[]");
std::string prev, cur;
if (start == std::string::npos) {
prev = "";
cur = prefix;
} else {
prev = std::string(prefix, 0, start + 1);
cur = std::string(prefix, start + 1);
}
size_t slash, dot;
if ((slash = cur.rfind('/')) != std::string::npos) {
try {
auto dir = std::string(cur, 0, slash);
auto prefix2 = std::string(cur, slash + 1);
for (auto & entry : DirectoryIterator{dir == "" ? "/" : dir}) {
checkInterrupt();
auto name = entry.path().filename().string();
if (name[0] != '.' && hasPrefix(name, prefix2))
completions.insert(prev + entry.path().string());
}
} catch (Error &) {
}
} else if ((dot = cur.rfind('.')) == std::string::npos) {
/* This is a variable name; look it up in the current scope. */
StringSet::iterator i = varNames.lower_bound(cur);
while (i != varNames.end()) {
if (i->substr(0, cur.size()) != cur) break;
completions.insert(prev + *i);
i++;
}
} else {
/* Temporarily disable the debugger, to avoid re-entering readline. */
auto debug_repl = state->debugRepl;
state->debugRepl = nullptr;
Finally restoreDebug([&]() { state->debugRepl = debug_repl; });
try {
/* This is an expression that should evaluate to an
attribute set. Evaluate it to get the names of the
attributes. */
auto expr = cur.substr(0, dot);
auto cur2 = cur.substr(dot + 1);
Expr * e = parseString(expr);
Value v;
e->eval(*state, *env, v);
state->forceAttrs(v, noPos, "while evaluating an attrset for the purpose of completion (this error should not be displayed; file an issue?)");
for (auto & i : *v.attrs()) {
std::string_view name = state->symbols[i.name];
if (name.substr(0, cur2.size()) != cur2) continue;
completions.insert(concatStrings(prev, expr, ".", name));
}
} catch (ParseError & e) {
// Quietly ignore parse errors.
} catch (EvalError & e) {
// Quietly ignore evaluation errors.
} catch (BadURL & e) {
// Quietly ignore BadURL flake-related errors.
} catch (FileNotFound & e) {
// Quietly ignore non-existent file being `import`-ed.
}
}
return completions;
}
// FIXME: DRY and match or use the parser
static bool isVarName(std::string_view s)
{
if (s.size() == 0) return false;
char c = s[0];
if ((c >= '0' && c <= '9') || c == '-' || c == '\'') return false;
for (auto & i : s)
if (!((i >= 'a' && i <= 'z') ||
(i >= 'A' && i <= 'Z') ||
(i >= '0' && i <= '9') ||
i == '_' || i == '-' || i == '\''))
return false;
return true;
}
StorePath NixRepl::getDerivationPath(Value & v) {
auto packageInfo = getDerivation(*state, v, false);
if (!packageInfo)
throw Error("expression does not evaluate to a derivation, so I can't build it");
auto drvPath = packageInfo->queryDrvPath();
if (!drvPath)
throw Error("expression did not evaluate to a valid derivation (no 'drvPath' attribute)");
if (!state->store->isValidPath(*drvPath))
throw Error("expression evaluated to invalid derivation '%s'", state->store->printStorePath(*drvPath));
return *drvPath;
}
void NixRepl::loadDebugTraceEnv(DebugTrace & dt)
{
initEnv();
auto se = state->getStaticEnv(dt.expr);
if (se) {
auto vm = mapStaticEnvBindings(state->symbols, *se.get(), dt.env);
// add staticenv vars.
for (auto & [name, value] : *(vm.get()))
addVarToScope(state->symbols.create(name), *value);
}
}
ProcessLineResult NixRepl::processLine(std::string line)
{
line = trim(line);
if (line.empty())
return ProcessLineResult::PromptAgain;
setInterrupted(false);
std::string command, arg;
if (line[0] == ':') {
size_t p = line.find_first_of(" \n\r\t");
command = line.substr(0, p);
if (p != std::string::npos) arg = removeWhitespace(line.substr(p));
} else {
arg = line;
}
if (command == ":?" || command == ":help") {
// FIXME: convert to Markdown, include in the 'nix repl' manpage.
std::cout
<< "The following commands are available:\n"
<< "\n"
<< " <expr> Evaluate and print expression\n"
<< " <x> = <expr> Bind expression to variable\n"
<< " :a, :add <expr> Add attributes from resulting set to scope\n"
<< " :b <expr> Build a derivation\n"
<< " :bl <expr> Build a derivation, creating GC roots in the\n"
<< " working directory\n"
<< " :e, :edit <expr> Open package or function in $EDITOR\n"
<< " :i <expr> Build derivation, then install result into\n"
<< " current profile\n"
<< " :l, :load <path> Load Nix expression and add it to scope\n"
<< " :lf, :load-flake <ref> Load Nix flake and add it to scope\n"
<< " :ll, :last-loaded Show most recently loaded variables added to scope\n"
<< " :p, :print <expr> Evaluate and print expression recursively\n"
<< " Strings are printed directly, without escaping.\n"
<< " :q, :quit Exit nix-repl\n"
<< " :r, :reload Reload all files\n"
<< " :sh <expr> Build dependencies of derivation, then start\n"
<< " nix-shell\n"
<< " :t <expr> Describe result of evaluation\n"
<< " :u <expr> Build derivation, then start nix-shell\n"
<< " :doc <expr> Show documentation of a builtin function\n"
<< " :log <expr> Show logs for a derivation\n"
<< " :te, :trace-enable [bool] Enable, disable or toggle showing traces for\n"
<< " errors\n"
<< " :?, :help Brings up this help menu\n"
;
if (state->debugRepl) {
std::cout
<< "\n"
<< " Debug mode commands\n"
<< " :env Show env stack\n"
<< " :bt, :backtrace Show trace stack\n"
<< " :st Show current trace\n"
<< " :st <idx> Change to another trace in the stack\n"
<< " :c, :continue Go until end of program, exception, or builtins.break\n"
<< " :s, :step Go one step\n"
;
}
}
else if (state->debugRepl && (command == ":bt" || command == ":backtrace")) {
for (const auto & [idx, i] : enumerate(state->debugTraces)) {
std::cout << "\n" << ANSI_BLUE << idx << ANSI_NORMAL << ": ";
showDebugTrace(std::cout, state->positions, i);
}
}
else if (state->debugRepl && (command == ":env")) {
for (const auto & [idx, i] : enumerate(state->debugTraces)) {
if (idx == debugTraceIndex) {
printEnvBindings(*state, i.expr, i.env);
break;
}
}
}
else if (state->debugRepl && (command == ":st")) {
try {
// change the DebugTrace index.
debugTraceIndex = stoi(arg);
} catch (...) { }
for (const auto & [idx, i] : enumerate(state->debugTraces)) {
if (idx == debugTraceIndex) {
std::cout << "\n" << ANSI_BLUE << idx << ANSI_NORMAL << ": ";
showDebugTrace(std::cout, state->positions, i);
std::cout << std::endl;
printEnvBindings(*state, i.expr, i.env);
loadDebugTraceEnv(i);
break;
}
}
}
else if (state->debugRepl && (command == ":s" || command == ":step")) {
// set flag to stop at next DebugTrace; exit repl.
state->debugStop = true;
return ProcessLineResult::Continue;
}
else if (state->debugRepl && (command == ":c" || command == ":continue")) {
// set flag to run to next breakpoint or end of program; exit repl.
state->debugStop = false;
return ProcessLineResult::Continue;
}
else if (command == ":a" || command == ":add") {
Value v;
evalString(arg, v);
addAttrsToScope(v);
}
else if (command == ":l" || command == ":load") {
state->resetFileCache();
loadFile(arg);
}
else if (command == ":lf" || command == ":load-flake") {
loadFlake(arg);
}
else if (command == ":ll" || command == ":last-loaded") {
showLastLoaded();
}
else if (command == ":r" || command == ":reload") {
state->resetFileCache();
reloadFilesAndFlakes();
}
else if (command == ":e" || command == ":edit") {
Value v;
evalString(arg, v);
const auto [path, line] = [&] () -> std::pair<SourcePath, uint32_t> {
if (v.type() == nPath || v.type() == nString) {
NixStringContext context;
auto path = state->coerceToPath(noPos, v, context, "while evaluating the filename to edit");
return {path, 0};
} else if (v.isLambda()) {
auto pos = state->positions[v.lambda().fun->pos];
if (auto path = std::get_if<SourcePath>(&pos.origin))
return {*path, pos.line};
else
throw Error("'%s' cannot be shown in an editor", pos);
} else {
// assume it's a derivation
return findPackageFilename(*state, v, arg);
}
}();
// Open in EDITOR
auto args = editorFor(path, line);
auto editor = args.front();
args.pop_front();
// runProgram redirects stdout to a StringSink,
// using runProgram2 to allow editors to display their UI
runProgram2(RunOptions { .program = editor, .lookupPath = true, .args = args , .isInteractive = true });
// Reload right after exiting the editor
state->resetFileCache();
reloadFilesAndFlakes();
}
else if (command == ":t") {
Value v;
evalString(arg, v);
logger->cout(showType(v));
}
else if (command == ":u") {
Value v, f, result;
evalString(arg, v);
evalString("drv: (import <nixpkgs> {}).runCommand \"shell\" { buildInputs = [ drv ]; } \"\"", f);
state->callFunction(f, v, result, PosIdx());
StorePath drvPath = getDerivationPath(result);
runNix("nix-shell", {state->store->printStorePath(drvPath)});
}
else if (command == ":b" || command == ":bl" || command == ":i" || command == ":sh" || command == ":log") {
Value v;
evalString(arg, v);
StorePath drvPath = getDerivationPath(v);
Path drvPathRaw = state->store->printStorePath(drvPath);
if (command == ":b" || command == ":bl") {
state->store->buildPaths({
DerivedPath::Built {
.drvPath = makeConstantStorePathRef(drvPath),
.outputs = OutputsSpec::All { },
},
});
auto drv = state->store->readDerivation(drvPath);
logger->cout("\nThis derivation produced the following outputs:");
for (auto & [outputName, outputPath] : state->store->queryDerivationOutputMap(drvPath)) {
auto localStore = state->store.dynamic_pointer_cast<LocalFSStore>();
if (localStore && command == ":bl") {
std::string symlink = "repl-result-" + outputName;
localStore->addPermRoot(outputPath, absPath(symlink));
logger->cout(" ./%s -> %s", symlink, state->store->printStorePath(outputPath));
} else {
logger->cout(" %s -> %s", outputName, state->store->printStorePath(outputPath));
}
}
} else if (command == ":i") {
runNix("nix-env", {"-i", drvPathRaw});
} else if (command == ":log") {
settings.readOnlyMode = true;
Finally roModeReset([&]() {
settings.readOnlyMode = false;
});
auto subs = getDefaultSubstituters();
subs.push_front(state->store);
bool foundLog = false;
RunPager pager;
for (auto & sub : subs) {
auto * logSubP = dynamic_cast<LogStore *>(&*sub);
if (!logSubP) {
printInfo("Skipped '%s' which does not support retrieving build logs", sub->getUri());
continue;
}
auto & logSub = *logSubP;
auto log = logSub.getBuildLog(drvPath);
if (log) {
printInfo("got build log for '%s' from '%s'", drvPathRaw, logSub.getUri());
logger->writeToStdout(*log);
foundLog = true;
break;
}
}
if (!foundLog) throw Error("build log of '%s' is not available", drvPathRaw);
} else {
runNix("nix-shell", {drvPathRaw});
}
}
else if (command == ":p" || command == ":print") {
Value v;
evalString(arg, v);
auto suspension = logger->suspend();
if (v.type() == nString) {
std::cout << v.string_view();
} else {
printValue(std::cout, v);
}
std::cout << std::endl;
}
else if (command == ":q" || command == ":quit") {
state->debugStop = false;
return ProcessLineResult::Quit;
}
else if (command == ":doc") {
Value v;
auto expr = parseString(arg);
std::string fallbackName;
PosIdx fallbackPos;
DocComment fallbackDoc;
if (auto select = dynamic_cast<ExprSelect *>(expr)) {
Value vAttrs;
auto name = select->evalExceptFinalSelect(*state, *env, vAttrs);
fallbackName = state->symbols[name];
state->forceAttrs(vAttrs, noPos, "while evaluating an attribute set to look for documentation");
auto attrs = vAttrs.attrs();
assert(attrs);
auto attr = attrs->get(name);
if (!attr) {
// When missing, trigger the normal exception
// e.g. :doc builtins.foo
// behaves like
// nix-repl> builtins.foo<tab>
// error: attribute 'foo' missing
evalString(arg, v);
assert(false);
}
if (attr->pos) {
fallbackPos = attr->pos;
fallbackDoc = state->getDocCommentForPos(fallbackPos);
}
}
evalString(arg, v);
if (auto doc = state->getDoc(v)) {
std::string markdown;
if (!doc->args.empty() && doc->name) {
auto args = doc->args;
for (auto & arg : args)
arg = "*" + arg + "*";
markdown +=
"**Synopsis:** `builtins." + (std::string) (*doc->name) + "` "
+ concatStringsSep(" ", args) + "\n\n";
}
markdown += stripIndentation(doc->doc);
logger->cout(trim(renderMarkdownToTerminal(markdown)));
} else if (fallbackPos) {
std::ostringstream ss;
ss << "Attribute `" << fallbackName << "`\n\n";
ss << " … defined at " << state->positions[fallbackPos] << "\n\n";
if (fallbackDoc) {
ss << fallbackDoc.getInnerText(state->positions);
} else {
ss << "No documentation found.\n\n";
}
auto markdown = toView(ss);
logger->cout(trim(renderMarkdownToTerminal(markdown)));
} else
throw Error("value does not have documentation");
}
else if (command == ":te" || command == ":trace-enable") {
if (arg == "false" || (arg == "" && loggerSettings.showTrace)) {
std::cout << "not showing error traces\n";
loggerSettings.showTrace = false;
} else if (arg == "true" || (arg == "" && !loggerSettings.showTrace)) {
std::cout << "showing error traces\n";
loggerSettings.showTrace = true;
} else {
throw Error("unexpected argument '%s' to %s", arg, command);
};
}
else if (command != "")
throw Error("unknown command '%1%'", command);
else {
size_t p = line.find('=');
std::string name;
if (p != std::string::npos &&
p < line.size() &&
line[p + 1] != '=' &&
isVarName(name = removeWhitespace(line.substr(0, p))))
{
Expr * e = parseString(line.substr(p + 1));
Value & v(*state->allocValue());
v.mkThunk(env, e);
addVarToScope(state->symbols.create(name), v);
} else {
Value v;
evalString(line, v);
auto suspension = logger->suspend();
printValue(std::cout, v, 1);
std::cout << std::endl;
}
}
return ProcessLineResult::PromptAgain;
}
void NixRepl::loadFile(const Path & path)
{
loadedFiles.remove(path);
loadedFiles.push_back(path);
Value v, v2;
state->evalFile(lookupFileArg(*state, path), v);
state->autoCallFunction(*autoArgs, v, v2);
addAttrsToScope(v2);
}
void NixRepl::loadFlake(const std::string & flakeRefS)
{
if (flakeRefS.empty())
throw Error("cannot use ':load-flake' without a path specified. (Use '.' for the current working directory.)");
loadedFlakes.remove(flakeRefS);
loadedFlakes.push_back(flakeRefS);
std::filesystem::path cwd;
try {
cwd = std::filesystem::current_path();
} catch (std::filesystem::filesystem_error & e) {
throw SysError("cannot determine current working directory");
}
auto flakeRef = parseFlakeRef(fetchSettings, flakeRefS, cwd.string(), true);
if (evalSettings.pureEval && !flakeRef.input.isLocked())
throw Error("cannot use ':load-flake' on locked flake reference '%s' (use --impure to override)", flakeRefS);
Value v;
flake::callFlake(*state,
flake::lockFlake(flakeSettings, *state, flakeRef,
flake::LockFlags {
.updateLockFile = false,
.useRegistries = !evalSettings.pureEval,
.allowUnlocked = !evalSettings.pureEval,
}),
v);
addAttrsToScope(v);
}
void NixRepl::initEnv()
{
env = &state->allocEnv(envSize);
env->up = &state->baseEnv;
displ = 0;
staticEnv->vars.clear();
varNames.clear();
for (auto & i : state->staticBaseEnv->vars)
varNames.emplace(state->symbols[i.first]);
}
void NixRepl::showLastLoaded()
{
RunPager pager;
for (auto & i : *lastLoaded.attrs()) {
std::string_view name = state->symbols[i.name];
logger->cout(name);
}
}
void NixRepl::reloadFilesAndFlakes()
{
initEnv();
loadFiles();
loadFlakes();
}
void NixRepl::loadFiles()
{
Strings old = loadedFiles;
loadedFiles.clear();
for (auto & i : old) {
notice("Loading '%1%'...", i);
loadFile(i);
}
for (auto & [i, what] : getValues()) {
notice("Loading installable '%1%'...", what);
addAttrsToScope(*i);
}
}
void NixRepl::loadFlakes()
{
Strings old = loadedFlakes;
loadedFlakes.clear();
for (auto & i : old) {
notice("Loading flake '%1%'...", i);
loadFlake(i);
}
}
void NixRepl::addAttrsToScope(Value & attrs)
{
state->forceAttrs(attrs, [&]() { return attrs.determinePos(noPos); }, "while evaluating an attribute set to be merged in the global scope");
if (displ + attrs.attrs()->size() >= envSize)
throw Error("environment full; cannot add more variables");
for (auto & i : *attrs.attrs()) {
staticEnv->vars.emplace_back(i.name, displ);
env->values[displ++] = i.value;
varNames.emplace(state->symbols[i.name]);
}
staticEnv->sort();
staticEnv->deduplicate();
notice("Added %1% variables.", attrs.attrs()->size());
lastLoaded = attrs;
const int max_print = 20;
int counter = 0;
std::ostringstream loaded;
for (auto & i : attrs.attrs()->lexicographicOrder(state->symbols)) {
if (counter >= max_print)
break;
if (counter > 0)
loaded << ", ";
printIdentifier(loaded, state->symbols[i->name]);
counter += 1;
}
notice("%1%", loaded.str());
if (attrs.attrs()->size() > max_print)
notice("... and %1% more; view with :ll", attrs.attrs()->size() - max_print);
}
void NixRepl::addVarToScope(const Symbol name, Value & v)
{
if (displ >= envSize)
throw Error("environment full; cannot add more variables");
if (auto oldVar = staticEnv->find(name); oldVar != staticEnv->vars.end())
staticEnv->vars.erase(oldVar);
staticEnv->vars.emplace_back(name, displ);
staticEnv->sort();
env->values[displ++] = &v;
varNames.emplace(state->symbols[name]);
}
Expr * NixRepl::parseString(std::string s)
{
return state->parseExprFromString(std::move(s), state->rootPath("."), staticEnv);
}
void NixRepl::evalString(std::string s, Value & v)
{
Expr * e;
try {
e = parseString(s);
} catch (ParseError & e) {
if (e.msg().find("unexpected end of file") != std::string::npos)
// For parse errors on incomplete input, we continue waiting for the next line of
// input without clearing the input so far.
throw IncompleteReplExpr(e.msg());
else
throw;
}
e->eval(*state, *env, v);
state->forceValue(v, v.determinePos(noPos));
}
void NixRepl::runNix(Path program, const Strings & args, const std::optional<std::string> & input)
{
if (runNixPtr)
(*runNixPtr)(program, args, input);
else
throw Error("Cannot run '%s' because no method of calling the Nix CLI was provided. This is a configuration problem pertaining to how this program was built. See Nix 2.25 release notes", program);
}
std::unique_ptr<AbstractNixRepl> AbstractNixRepl::create(
const LookupPath & lookupPath, nix::ref<Store> store, ref<EvalState> state,
std::function<AnnotatedValues()> getValues, RunNix * runNix)
{
return std::make_unique<NixRepl>(
lookupPath,
std::move(store),
state,
getValues,
runNix
);
}
ReplExitStatus AbstractNixRepl::runSimple(
ref<EvalState> evalState,
const ValMap & extraEnv)
{
auto getValues = [&]()->NixRepl::AnnotatedValues{
NixRepl::AnnotatedValues values;
return values;
};
LookupPath lookupPath = {};
auto repl = std::make_unique<NixRepl>(
lookupPath,
openStore(),
evalState,
getValues,
/*runNix=*/nullptr
);
repl->initEnv();
// add 'extra' vars.
for (auto & [name, value] : extraEnv)
repl->addVarToScope(repl->state->symbols.create(name), *value);
return repl->mainLoop();
}
}