lix/src/nix-instantiate/main.cc
Eelco Dolstra ee401afad8 * Mode --parse-only' to parse the input (on stdin, -'), and print
out the AST as an ATerm.
* Mode `--eval-only' to parse and evaluate the input, and print the
  resulting normal form as an ATerm.

Neither of these modes require store/DB write permission.
2004-10-26 16:59:36 +00:00

121 lines
2.8 KiB
C++

#include <map>
#include <iostream>
#include "globals.hh"
#include "normalise.hh"
#include "shared.hh"
#include "eval.hh"
#include "parser.hh"
#include "help.txt.hh"
void printHelp()
{
cout << string((char *) helpText, sizeof helpText);
}
static Expr evalStdin(EvalState & state, bool parseOnly)
{
startNest(nest, lvlTalkative, format("evaluating standard input"));
string s, s2;
while (getline(cin, s2)) s += s2 + "\n";
Expr e = parseExprFromString(state, s, absPath("."));
return parseOnly ? e : evalExpr(state, e);
}
static void printDrvPaths(EvalState & state, Expr e)
{
ATMatcher m;
ATermList es;
/* !!! duplication w.r.t. parseDerivations in nix-env */
if (atMatch(m, e) >> "Attrs" >> es) {
Expr a = queryAttr(e, "type");
if (a && evalString(state, a) == "derivation") {
a = queryAttr(e, "drvPath");
if (a) {
cout << format("%1%\n") % evalPath(state, a);
return;
}
throw Error("bad derivation");
} else {
ATermMap drvMap;
queryAllAttrs(e, drvMap);
for (ATermIterator i(drvMap.keys()); i; ++i)
printDrvPaths(state, evalExpr(state, drvMap.get(*i)));
return;
}
}
if (atMatch(m, e) >> "List" >> es) {
for (ATermIterator i(es); i; ++i)
printDrvPaths(state, evalExpr(state, *i));
return;
}
throw Error("expression does not evaluate to one or more derivations");
}
static void printResult(EvalState & state, Expr e, bool evalOnly)
{
if (evalOnly)
cout << format("%1%\n") % e;
else
printDrvPaths(state, e);
}
void run(Strings args)
{
EvalState state;
Strings files;
bool readStdin = false;
bool evalOnly = false;
bool parseOnly = false;
for (Strings::iterator it = args.begin();
it != args.end(); )
{
string arg = *it++;
if (arg == "-")
readStdin = true;
else if (arg == "--eval-only") {
readOnlyMode = true;
evalOnly = true;
}
else if (arg == "--parse-only") {
readOnlyMode = true;
parseOnly = evalOnly = true;
}
else if (arg[0] == '-')
throw UsageError(format("unknown flag `%1%`") % arg);
else
files.push_back(arg);
}
openDB();
if (readStdin) {
Expr e = evalStdin(state, parseOnly);
printResult(state, e, evalOnly);
}
for (Strings::iterator it = files.begin();
it != files.end(); it++)
{
Expr e = evalFile(state, absPath(*it));
/* !!! parseOnly ignored */
printResult(state, e, evalOnly);
}
printEvalStats(state);
}
string programId = "nix-instantiate";