private Expr cleanupOpExpr(OpExpr opExp) {
FunctionalRef ref = opExp.getOp();
List<Expr> args = opExp.getArgs();
if (args.size() <= 1) return opExp;
IdOrOp name = ref.getNames().get(0);
if (!(name instanceof Op)) return bug(name, "The name field of OpRef should be Op.");
Op qop = (Op) name;
if (OprUtil.isEnclosing(qop)) return opExp;
if (OprUtil.isUnknownFixity(qop))
return bug(opExp, "The operator fixity is unknown: " + ((Op) qop).getText());
boolean prefix = OprUtil.hasPrefixColon(qop);
boolean suffix = OprUtil.hasSuffixColon(qop);
if (!prefix && !suffix) return opExp;
qop = OprUtil.noColon(qop);
Iterator<Expr> i = args.iterator();
Expr res = i.next();
Span sp = NodeUtil.getSpan(opExp);
for (Expr arg : Iter.iter(i)) {
if (prefix) {
res = thunk(res);
}
if (suffix) {
arg = thunk(arg);
}
res = ExprFactory.makeOpExpr(sp, qop, res, arg);
}
return res;
}
@Override
public Node forOpExpr(OpExpr that) {
FunctionalRef op_result = (FunctionalRef) recur(that.getOp());
/**
* * For BIG OP <| BIG OT <| f y | y <- ys |> | ys <- gg |> Is this case, BIG <||> is being
* removed. The nested reduction is replaced with __bigOperator2(BIG OP, BIG OT, gg)
*
* <p>by Kento
*/
String str = op_result.toString();
String theListEnclosingOperatorName = "BIG <| BIG |>";
String someBigOperatorName = "BIG";
// make sure the body is of application of some big operator
if ((str.length() >= someBigOperatorName.length()
&& str.substring(0, someBigOperatorName.length()).equals(someBigOperatorName))) {
// make sure that BIG OP (Accumulator (BIG <||>, gs))
if (that.getArgs().size() == 1
&& that.getArgs().get(0) instanceof Accumulator
&& ((Accumulator) that.getArgs().get(0))
.getAccOp()
.toString()
.equals(theListEnclosingOperatorName)) {
Accumulator acc = (Accumulator) that.getArgs().get(0);
Expr body = visitGenerators(NodeUtil.getSpan(acc), acc.getGens(), acc.getBody());
/**
* * If the accumulation is a nested reduction like <| BIG OT <| f y | y <- ys |> | ys <- gg
* |> , visitGenerators returns a tuple of ((BIG OT, f), gg) (this should be refactored,
* though) In this case, the nested reduction is replaced with __bigOperator2
*/
if (body instanceof TupleExpr) {
// a tuple of the inner Accumulator (op, body) and the gg
TupleExpr tuple = (TupleExpr) body;
TupleExpr innerAccumTuple = (TupleExpr) tuple.getExprs().get(0);
Expr opexpI = (Expr) innerAccumTuple.getExprs().get(0);
Expr innerBody = (Expr) innerAccumTuple.getExprs().get(1);
FunctionalRef ref = (FunctionalRef) op_result;
IdOrOp name = ref.getNames().get(0);
// make sure the operator is actually an operator
if (!(name instanceof Op)) return null;
Expr opexpO =
ExprFactory.makeOpExpr(NodeUtil.getSpan(that), (Op) name, ref.getStaticArgs());
Expr gg = tuple.getExprs().get(1);
Expr res =
ExprFactory.make_RewriteFnApp(
NodeUtil.getSpan(that),
BIGOP2_NAME,
ExprFactory.makeTupleExpr(NodeUtil.getSpan(body), opexpO, opexpI, gg, innerBody));
return (Expr) recur(res);
}
}
}
List<Expr> args_result = recurOnListOfExpr(that.getArgs());
OpExpr new_op;
if (op_result == that.getOp() && args_result == that.getArgs()) {
new_op = that;
} else {
new_op =
ExprFactory.makeOpExpr(
NodeUtil.getSpan(that),
NodeUtil.isParenthesized(that),
NodeUtil.getExprType(that),
op_result,
args_result);
}
return cleanupOpExpr(new_op);
}