public static SqlExpr substitute(SqlExpr expr, Factory1<SqlExpr> postTraversalTransformer) {
if (expr == null) {
System.out.println("Null expr");
}
assert expr != null : "Expr must not be null";
assert expr.getType() != null : "Type of exprs must not be null";
SqlExpr result;
switch (expr.getType()) {
case Constant:
{
// result = expr;
result = postTraversalTransformer.create(expr);
break;
}
case Function:
{
SqlExprFunction fn = expr.asFunction();
List<SqlExpr> args = fn.getArgs();
assert !Iterables.contains(args, null) : "Null argument in expr: " + fn;
List<SqlExpr> newArgs = substitute(args, postTraversalTransformer);
SqlExpr tmp = fn.copy(newArgs);
result = postTraversalTransformer.create(tmp);
break;
}
case Variable:
{
// S_ColumnRef columnRef = (S_ColumnRef)expr;
// SqlExprVar var = expr.asVariable();
// String name = var.getVarName();
result = postTraversalTransformer.create(expr); // map.get(name);
/*
if(substitute != null) {
result = substitute;
} else {
result = expr;
}
)*/
// columnRef.ge
// The datatype of the substituted expression must be an equal-or-sub-type of the current
// one.
// result = null;
// if(true) { throw new RuntimeException("todo"); }
break;
}
default:
{
throw new RuntimeException("Should not happen");
}
}
return result;
}