* `nix-instantiate --print-args' prints out the arguments of a

top-level function.
This commit is contained in:
Eelco Dolstra 2006-07-25 21:21:50 +00:00
parent 0e6dc72a7a
commit 2317d8f671
3 changed files with 28 additions and 7 deletions

View file

@ -124,15 +124,15 @@ static void getDerivations(EvalState & state, Expr e,
DrvInfos & drvs, Exprs & doneExprs, const string & attrPath,
const string & pathTaken)
{
/* Automatically call functions that have defaults for all
arguments. */
/* Automatically call functions for which each argument has a
default value. */
ATermList formals;
ATerm body, pos;
if (matchFunction(e, formals, body, pos)) {
for (ATermIterator i(formals); i; ++i) {
Expr name, def; ATerm values, def2;
if (!matchFormal(*i, name, values, def2)) abort();
if (!matchDefaultValue(def2, def))
if (!matchDefaultValue(def2, def))
throw TypeError(format("cannot auto-call a function that has an argument without a default value (`%1%')")
% aterm2String(name));
}

View file

@ -15,4 +15,6 @@ Options:
--eval-only: evaluate and print resulting term; do not instantiate
--parse-only: parse and print abstract syntax tree
--attr / -A PATH: select an attribute from the top-level expression
--add-root: add garbage collector roots for the result

View file

@ -33,11 +33,25 @@ static int rootNr = 0;
static bool indirectRoot = false;
static void printResult(EvalState & state, Expr e, bool evalOnly,
const string & attrPath)
static void printResult(EvalState & state, Expr e,
bool evalOnly, bool printArgs, const string & attrPath)
{
if (evalOnly)
cout << format("%1%\n") % e;
else if (printArgs) {
ATermList formals;
ATerm body, pos;
if (matchFunction(e, formals, body, pos)) {
for (ATermIterator i(formals); i; ++i) {
Expr name; ATerm d1, d2;
if (!matchFormal(*i, name, d1, d2)) abort();
cout << format("%1%\n") % aterm2String(name);
}
} else
printMsg(lvlError, "warning: expression does not evaluate to a function");
}
else {
DrvInfos drvs;
getDerivations(state, e, drvs, attrPath);
@ -62,6 +76,7 @@ void run(Strings args)
bool readStdin = false;
bool evalOnly = false;
bool parseOnly = false;
bool printArgs = false;
string attrPath;
for (Strings::iterator i = args.begin();
@ -79,6 +94,10 @@ void run(Strings args)
readOnlyMode = true;
parseOnly = evalOnly = true;
}
else if (arg == "--print-args") {
readOnlyMode = true;
printArgs = true;
}
else if (arg == "--add-root") {
if (i == args.end())
throw UsageError("`--add-root requires an argument");
@ -101,7 +120,7 @@ void run(Strings args)
if (readStdin) {
Expr e = evalStdin(state, parseOnly);
printResult(state, e, evalOnly, attrPath);
printResult(state, e, evalOnly, printArgs, attrPath);
}
for (Strings::iterator i = files.begin();
@ -111,7 +130,7 @@ void run(Strings args)
Expr e = parseOnly
? parseExprFromFile(state, path)
: evalFile(state, path);
printResult(state, e, evalOnly, attrPath);
printResult(state, e, evalOnly, printArgs, attrPath);
}
printEvalStats(state);