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#include "nixexpr.hh"
#include "derivations.hh"
#include "util.hh"
#include <cstdlib>
namespace nix {
std::ostream & operator << (std::ostream & str, Expr & e)
{
e.show(str);
return str;
}
void ExprInt::show(std::ostream & str)
{
str << n;
}
void ExprString::show(std::ostream & str)
{
str << "\"" << s << "\""; // !!! escaping
}
void ExprPath::show(std::ostream & str)
{
str << s;
}
void ExprVar::show(std::ostream & str)
{
str << name;
}
void ExprSelect::show(std::ostream & str)
{
str << "(" << *e << ")." << name;
}
void ExprAttrs::show(std::ostream & str)
{
if (recursive) str << "rec ";
str << "{ ";
foreach (list<string>::iterator, i, inherited)
str << "inherited " << *i << "; ";
foreach (Attrs::iterator, i, attrs)
str << i->first << " = " << *i->second << "; ";
str << "}";
}
void ExprList::show(std::ostream & str)
{
str << "[ ";
foreach (vector<Expr *>::iterator, i, elems)
str << "(" << **i << ") ";
str << "]";
}
void ExprLambda::show(std::ostream & str)
{
str << "(";
if (matchAttrs) {
str << "{ ";
bool first = true;
foreach (Formals::Formals_::iterator, i, formals->formals) {
if (first) first = false; else str << ", ";
str << i->name;
if (i->def) str << " ? " << *i->def;
}
str << " }";
if (arg != "") str << " @ ";
}
if (arg != "") str << arg;
str << ": " << *body << ")";
}
void ExprWith::show(std::ostream & str)
{
str << "with " << *attrs << "; " << *body;
}
void ExprIf::show(std::ostream & str)
{
str << "if " << *cond << " then " << *then << " else " << *else_;
}
#if 0
string showPos(ATerm pos)
{
ATerm path;
int line, column;
if (matchNoPos(pos)) return "undefined position";
if (!matchPos(pos, path, line, column))
throw badTerm("position expected", pos);
return (format("`%1%:%2%:%3%'") % aterm2String(path) % line % column).str();
}
ATerm bottomupRewrite(TermFun & f, ATerm e)
{
checkInterrupt();
if (ATgetType(e) == AT_APPL) {
AFun fun = ATgetAFun(e);
int arity = ATgetArity(fun);
ATerm args[arity];
for (int i = 0; i < arity; ++i)
args[i] = bottomupRewrite(f, ATgetArgument(e, i));
e = (ATerm) ATmakeApplArray(fun, args);
}
else if (ATgetType(e) == AT_LIST) {
ATermList in = (ATermList) e;
ATermList out = ATempty;
for (ATermIterator i(in); i; ++i)
out = ATinsert(out, bottomupRewrite(f, *i));
e = (ATerm) ATreverse(out);
}
return f(e);
}
Expr makeAttrs(const ATermMap & attrs)
{
ATermList bnds = ATempty;
for (ATermMap::const_iterator i = attrs.begin(); i != attrs.end(); ++i) {
Expr e;
ATerm pos;
if (!matchAttrRHS(i->value, e, pos))
abort(); /* can't happen */
bnds = ATinsert(bnds, makeBind(i->key, e, pos));
}
return makeAttrs(bnds);
}
static void varsBoundByPattern(ATermMap & map, Pattern pat)
{
ATerm name;
ATermList formals;
ATermBool ellipsis;
/* Use makeRemoved() so that it can be used directly in
substitute(). */
if (matchVarPat(pat, name))
map.set(name, makeRemoved());
else if (matchAttrsPat(pat, formals, ellipsis, name)) {
if (name != sNoAlias) map.set(name, makeRemoved());
for (ATermIterator i(formals); i; ++i) {
ATerm d1;
if (!matchFormal(*i, name, d1)) abort();
map.set(name, makeRemoved());
}
}
else abort();
}
/* We use memoisation to prevent exponential complexity on heavily
shared ATerms (remember, an ATerm is a graph, not a tree!). Note
that using an STL set is fine here wrt to ATerm garbage collection
since all the ATerms in the set are already reachable from
somewhere else. */
static void checkVarDefs2(set<Expr> & done, const ATermMap & defs, Expr e)
{
if (done.find(e) != done.end()) return;
done.insert(e);
ATerm name, pos, value;
ATerm with, body;
ATermList rbnds, nrbnds;
Pattern pat;
/* Closed terms don't have free variables, so we don't have to
check by definition. */
if (matchClosed(e, value)) return;
else if (matchVar(e, name)) {
if (!defs.get(name))
throw EvalError(format("undefined variable `%1%'")
% aterm2String(name));
}
else if (matchFunction(e, pat, body, pos)) {
ATermMap defs2(defs);
varsBoundByPattern(defs2, pat);
set<Expr> done2;
checkVarDefs2(done2, defs2, pat);
checkVarDefs2(done2, defs2, body);
}
else if (matchRec(e, rbnds, nrbnds)) {
checkVarDefs2(done, defs, (ATerm) nrbnds);
ATermMap defs2(defs);
for (ATermIterator i(rbnds); i; ++i) {
if (!matchBind(*i, name, value, pos)) abort(); /* can't happen */
defs2.set(name, (ATerm) ATempty);
}
for (ATermIterator i(nrbnds); i; ++i) {
if (!matchBind(*i, name, value, pos)) abort(); /* can't happen */
defs2.set(name, (ATerm) ATempty);
}
set<Expr> done2;
checkVarDefs2(done2, defs2, (ATerm) rbnds);
}
else if (matchWith(e, with, body, pos)) {
/* We can't check the body without evaluating the definitions
(which is an arbitrary expression), so we don't do that
here but only when actually evaluating the `with'. */
checkVarDefs2(done, defs, with);
}
else if (ATgetType(e) == AT_APPL) {
int arity = ATgetArity(ATgetAFun(e));
for (int i = 0; i < arity; ++i)
checkVarDefs2(done, defs, ATgetArgument(e, i));
}
else if (ATgetType(e) == AT_LIST)
for (ATermIterator i((ATermList) e); i; ++i)
checkVarDefs2(done, defs, *i);
}
void checkVarDefs(const ATermMap & defs, Expr e)
{
set<Expr> done;
checkVarDefs2(done, defs, e);
}
#endif
}
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