//block -> {decls statements}
void block(){
match('{');
enviroment saved_env = top;
top = Enviroment(top);
decls();
stmts();
match('}');
top = saved_env;
}
int decls() {
printf("%d\n", a);
if (a > 0) {
a = a - 1;
return decls();
}
else {
a = 0;
return a;
}
}
LetRecNode::LetRecNode(Compiler &compiler, const iter_t &node, bool isProgram)
: Node(compiler, Node_ExprLetRec), _isProgram(isProgram)
{
unsigned j;
unsigned jmax = node->children.size();
/*
If this an usual letrec, not the program, then don't parse the last
child element as an "in" expression.
*/
if (!isProgram) jmax -= 1;
_expr = 0;
// Parse RDecls
map<string, RDecl*> vars;
for (j = 0; j < jmax; j++) {
RDecl *rd = new RDecl(compiler, node->children.begin() + j);
if (vars.insert(make_pair(rd->alias, rd)).second == false) {
throw logic_error("Multiple declarations of \"" + rd->alias + "\".");
}
if (isProgram && compiler.testFlag(Compiler::OptimizeMain) && rd->alias == "main") {
_expr = rd->expr;
} else {
_decls.push_back(rd);
}
}
vars.clear(); // We're being very memory efficient here. Embedded here we come!
if (isProgram) {
if (!compiler.testFlag(Compiler::OptimizeMain)) {
_expr = new IdentNode(compiler, "main");
}
} else {
_expr = Node::nodeFactory(compiler, node->children.begin() + j);
}
assert(_expr != 0);
// Optimize out unused declarations
if (!_decls.empty() && compiler.testFlag(Compiler::OptimizeUnused)) {
DEBUGMSG("Optimizing unused variables:");
std::vector<RDecl*> decls(_decls);
_decls.clear();
unsigned n = decls.size();
BoolMatrix b(n + 1, n + 1, false);
for (unsigned c = 0; c < n; c++) {
for (unsigned r = 0; r < n; r++) {
if (decls.at(r)->expr->usesVariable(decls.at(c)->alias)) {
b.data[r][c] = true;
}
}
if (_expr->usesVariable(decls.at(c)->alias)) {
b.data[n][c] = true;
}
}
b.transformToTransitiveClosure();
#ifdef DEBUG
unsigned unused = 0;
#endif
for (unsigned i = 0; i < n; i++) {
if (b.data[n][i]) {
_decls.push_back(decls.at(i));
} else {
DEBUGMSG("Found unused variable \"" + decls.at(i)->alias + "\" in letrec.");
#ifdef DEBUG
unused++;
#endif
}
}
DEBUGMSG("Found " + intToString(unused) + ".");
}
// Reorder cyclic definitions
if (_decls.size() > 1 && compiler.testFlag(Compiler::OptimizeLetRecDecls)) {
BoolMatrix b(_decls.size(), _decls.size(), true);
for (unsigned c = 0; c < _decls.size(); c++) {
for (unsigned r = 0; r < _decls.size(); r++) {
if (c == r) {
b.data[r][r] = false; // Set identity values
} else if (_decls.at(r)->expr->usesVariable(_decls.at(c)->alias)) {
b.data[r][c] = false;
}
}
}
unsigned n = _decls.size();
vector<RDecl*> d(_decls);
_decls.clear();
unsigned *ds = new unsigned[n];
for (unsigned i = 0; i < n; i++) ds[i] = i;
MySort mySort(&b);
stable_sort(ds, ds + n, mySort);
for (unsigned i = 0; i < n; i++) _decls.push_back(d.at(ds[i]));
delete ds;
}
}
int main() {
printf("Enter a:\n");
// scanf("%d",a);
a = 3;
printf("%d\n", decls());
}
