nil은 :scm/unresolved를 대신함

src/scm.clj

@@ -1,13 +1,11 @@
 (ns scm
   (:refer-clojure :exclude [read])
-  (:require
-   [clojure.core.match :refer [match]]
-   [clojure.java.io :as io]
-   [clojure.pprint]
-   [instaparse.core :as insta]
-   [clojure.spec.alpha :as s])
-  (:import
-   (clojure.lang ILookup)))
+  (:require [clojure.core.match :refer [match]]
+            [clojure.java.io :as io]
+            [clojure.pprint]
+            [instaparse.core :as insta]
+            [clojure.spec.alpha :as s])
+  (:import (clojure.lang ILookup)))
 
 
 ;;; syntax objects
@@ -20,13 +18,14 @@
   (satisfies? ISyntax x))
 
 (deftype Syntax [datum ctx]
+  :load-ns true ; 왜?
   Object
   (equals [x y]
     (or (identical? x y)
         (and (satisfies? ISyntax y)
              (.equals datum (syntax-e y))
              (.equals ctx (syntax-context y)))))
-  ISyntax
+  scm/ISyntax
   (syntax-e [this] datum)
   (syntax-context [this] ctx))
 
@@ -42,7 +41,8 @@
   ;; 더 좋은 방법은 생각하고 있다. 모든 라이브러리나 프로그램은
   ;; top-level scope를 짓겠는다. 그때 nil/#{}는 `::unresolved`를
   ;; 대신하고 하나의 scope를 이루어진 집합은 #{}를 대신하겠는다.
-  (= (syntax-context stx) ::unresolved))
+  #_(= (syntax-context stx) ::unresolved)
+  (empty? (syntax-context stx)))
 
 (defn resolved? [stx]
   (not (unresolved? stx)))
@@ -69,11 +69,11 @@
 (defn stx-reader [x]
   (if-let [[datum ctx] (and (vector? x) x)]
     (->Syntax datum ctx)
-    (->Syntax x ::unresolved)))
+    (->Syntax x nil)))
 
 (defn datum->syntax
   ([datum]
-   (->Syntax datum ::unresolved))
+   (->Syntax datum nil))
   ([datum ctxt-donor]
    (->Syntax datum (syntax-context ctxt-donor))))
 
@@ -143,7 +143,9 @@
                 instaparse {}}}]
   (let [r (insta/parse r7rs-parser text
                        :start (if library? :library-start :datum-start)
-                       instaparse)]
+                       instaparse)
+        #_#_scopeholder (when syntax?
+                          (->Syntax nil #{(new-scope "toplevel_")}))]
     (if (insta/failure? r)
       (if throw?
         (throw (ex-info "reader error" {:err r}))
@@ -165,10 +167,10 @@
         ;; 그라머에 datum을 감추지 않은 고러서 대신 여기 모든 datum을
         ;; 과정할 수 있었더다. 작업 한 개만으로 syntax object들 다
         ;; 만들 수 있어서 이럼은 더 좋다.
-        :datum (fn [x]
-                 (if syntax?
-                   (datum->syntax x)
-                   x))
+        :datum #(if syntax?
+                  #_(datum->syntax % scopeholder)
+                  (datum->syntax %)
+                  %)
         :number identity
         :symbol symbol
         :string (fn [& els]