clojure java 交互 语法糖 展开点

public static Object macroexpand1(Object x) {
        if (x instanceof ISeq) {
            ISeq form = (ISeq)x;
            Object op = RT.first(form);
            if (isSpecial(op)) {
                return x;
            }

            Var v = isMacro(op);
            if (v != null) {
                ISeq args = RT.cons(form, RT.cons(LOCAL_ENV.get(), form.next()));
                return v.applyTo(args);
            }

 // 这里如果是 java.util.Date/pares 等形式. 则变(展开)成 new 或  dot(.) special form 
            if (op instanceof Symbol) { 
                Symbol sym = (Symbol)op;
                String sname = sym.name;
                Symbol target;
                if (sym.name.charAt(0) == '.') {
                    if (RT.length(form) < 2) {
                        throw new IllegalArgumentException("Malformed member expression, expecting (.member target ...)");
                    }

                    target = Symbol.intern(sname.substring(1));
                    Object target = RT.second(form);
                    if (Compiler.HostExpr.maybeClass(target, false) != null) {
                        target = ((IObj)RT.list(IDENTITY, target)).withMeta(RT.map(new Object[]{RT.TAG_KEY, CLASS}));
                    }

                    return preserveTag(form, RT.listStar(DOT, target, target, form.next().next()));
                }

                if (namesStaticMember(sym)) {
                    target = Symbol.intern(sym.ns);
                    Class c = Compiler.HostExpr.maybeClass(target, false);
                    if (c != null) {
                        Symbol meth = Symbol.intern(sym.name);
                        return preserveTag(form, RT.listStar(DOT, target, meth, form.next()));
                    }
                } else {
                    int idx = sname.lastIndexOf(46);
                    if (idx == sname.length() - 1) {
                        return RT.listStar(NEW, Symbol.intern(sname.substring(0, idx)), form.next());
                    }
                }
            }
        }

        return x;
    }