Implement macros with maps instead of vectors.

Output of macros will probably be more readable. Inline _macro_wrap and _unwrap for efficiency (there are less primitive operations for maps than for vectors). Basic check of `map?` and `macro?`. Swap them in order to simplify the diff with cb9b065.
kanaka · Jul 14, 2019 · 809d74c · 809d74c
1 parent cb9b065
commit 809d74c
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Showing 6 changed files with 35 additions and 41 deletions.
diff --git a/mal/core.mal b/mal/core.mal
@@ -1,27 +1,13 @@
-(def! _macro_magic
-  :_I_tell_ya_this_is_a_MAL_macro_mark_my_words)
-
-(def! _macro_wrap (fn* [f]
-  [_macro_magic f]))
-
-(def! _macro_unwrap (fn* [x]
-  (if (vector? x)
-    (if (= (first x) _macro_magic)
-      (nth x 1)))))
+(def! _map? (fn* [x]
+  (if (map? x)
+    (not (= (keys x) '(:__MAL_MACRO__)))
+    false)))
 
 (def! _macro? (fn* [x]
-  (if (_macro_unwrap x)
-    true
+  (if (map? x)
+    (= (keys x) '(:__MAL_MACRO__))
     false)))
 
-(def! false_on_macro (fn* [f]
-  (fn* [x]
-    (if (_macro_unwrap x)
-      false
-      (f x)))))
-(def! _sequential? (false_on_macro sequential?))
-(def! _vector? (false_on_macro vector?))
-
 (def! core_ns
   [['= =]
    ['throw throw]
@@ -57,17 +43,17 @@
    ['list list]
    ['list? list?]
    ['vector vector]
-   ['vector? _vector?]
+   ['vector? vector?]
    ['hash-map hash-map]
-   ['map? map?]
+   ['map? _map?]
    ['assoc assoc]
    ['dissoc dissoc]
    ['get get]
    ['contains? contains?]
    ['keys keys]
    ['vals vals]
 
-   ['sequential? _sequential?]
+   ['sequential? sequential?]
    ['cons cons]
    ['concat concat]
    ['nth nth]

diff --git a/mal/step8_macros.mal b/mal/step8_macros.mal
@@ -29,7 +29,9 @@
     (let* [a0 (first ast)]
       (if (symbol? a0)
         (if (env-find env a0)
-          (_macro_unwrap (env-get env a0))))))))
+          (let* [m (env-get env a0)]
+            (if (_macro? m)
+              (get m :__MAL_MACRO__)))))))))
 
 (def! MACROEXPAND (fn* [ast env]
   (let* [m (is-macro-call ast env)]
@@ -44,9 +46,9 @@
 
     (list? ast)   (map (fn* [exp] (EVAL exp env)) ast)
 
-    (_vector? ast) (apply vector (map (fn* [exp] (EVAL exp env)) ast))
+    (vector? ast) (apply vector (map (fn* [exp] (EVAL exp env)) ast))
 
-    (map? ast)    (apply hash-map
+    (_map? ast)   (apply hash-map
                       (apply concat
                         (map (fn* [k] [k (EVAL (get ast k) env)])
                              (keys ast))))
@@ -85,7 +87,7 @@
           (EVAL (QUASIQUOTE (nth ast 1)) env)
 
           (= 'defmacro! a0)
-          (env-set env (nth ast 1) (_macro_wrap (EVAL (nth ast 2) env)))
+          (env-set env (nth ast 1) {:__MAL_MACRO__ (EVAL (nth ast 2) env)})
 
           (= 'macroexpand a0)
           (MACROEXPAND (nth ast 1) env)
@@ -109,8 +111,7 @@
 
 
 ;; print
-(def! PRINT (fn* [x]
-  (pr-str (let* [m (_macro_unwrap x)] (if m m x)))))
+(def! PRINT pr-str)
 
 ;; repl
 (def! repl-env (new-env))

diff --git a/mal/step9_try.mal b/mal/step9_try.mal
@@ -29,7 +29,9 @@
     (let* [a0 (first ast)]
       (if (symbol? a0)
         (if (env-find env a0)
-          (_macro_unwrap (env-get env a0))))))))
+          (let* [m (env-get env a0)]
+            (if (_macro? m)
+              (get m :__MAL_MACRO__)))))))))
 
 (def! MACROEXPAND (fn* [ast env]
   (let* [m (is-macro-call ast env)]
@@ -44,9 +46,9 @@
 
     (list? ast)   (map (fn* [exp] (EVAL exp env)) ast)
 
-    (_vector? ast) (apply vector (map (fn* [exp] (EVAL exp env)) ast))
+    (vector? ast) (apply vector (map (fn* [exp] (EVAL exp env)) ast))
 
-    (map? ast)    (apply hash-map
+    (_map? ast)   (apply hash-map
                       (apply concat
                         (map (fn* [k] [k (EVAL (get ast k) env)])
                              (keys ast))))
@@ -85,7 +87,7 @@
           (EVAL (QUASIQUOTE (nth ast 1)) env)
 
           (= 'defmacro! a0)
-          (env-set env (nth ast 1) (_macro_wrap (EVAL (nth ast 2) env)))
+          (env-set env (nth ast 1) {:__MAL_MACRO__ (EVAL (nth ast 2) env)})
 
           (= 'macroexpand a0)
           (MACROEXPAND (nth ast 1) env)
@@ -118,8 +120,7 @@
 
 
 ;; print
-(def! PRINT (fn* [x]
-  (pr-str (let* [m (_macro_unwrap x)] (if m m x)))))
+(def! PRINT pr-str)
 
 ;; repl
 (def! repl-env (new-env))

diff --git a/mal/stepA_mal.mal b/mal/stepA_mal.mal
@@ -29,7 +29,9 @@
     (let* [a0 (first ast)]
       (if (symbol? a0)
         (if (env-find env a0)
-          (_macro_unwrap (env-get env a0))))))))
+          (let* [m (env-get env a0)]
+            (if (_macro? m)
+              (get m :__MAL_MACRO__)))))))))
 
 (def! MACROEXPAND (fn* [ast env]
   (let* [m (is-macro-call ast env)]
@@ -44,9 +46,9 @@
 
     (list? ast)   (map (fn* [exp] (EVAL exp env)) ast)
 
-    (_vector? ast) (apply vector (map (fn* [exp] (EVAL exp env)) ast))
+    (vector? ast) (apply vector (map (fn* [exp] (EVAL exp env)) ast))
 
-    (map? ast)    (apply hash-map
+    (_map? ast)   (apply hash-map
                       (apply concat
                         (map (fn* [k] [k (EVAL (get ast k) env)])
                              (keys ast))))
@@ -85,7 +87,7 @@
           (EVAL (QUASIQUOTE (nth ast 1)) env)
 
           (= 'defmacro! a0)
-          (env-set env (nth ast 1) (_macro_wrap (EVAL (nth ast 2) env)))
+          (env-set env (nth ast 1) {:__MAL_MACRO__ (EVAL (nth ast 2) env)})
 
           (= 'macroexpand a0)
           (MACROEXPAND (nth ast 1) env)
@@ -118,8 +120,7 @@
 
 
 ;; print
-(def! PRINT (fn* [x]
-  (pr-str (let* [m (_macro_unwrap x)] (if m m x)))))
+(def! PRINT pr-str)
 
 ;; repl
 (def! repl-env (new-env))

diff --git a/tests/step9_try.mal b/tests/step9_try.mal
@@ -177,6 +177,7 @@
 (map? :abc)
 ;=>false
 
+
 ;;
 ;; Testing hash-maps
 (hash-map "a" 1)
@@ -377,3 +378,5 @@
 (= [] {})
 ;=>false
 
+(map? cond)
+;=>false
diff --git a/tests/stepA_mal.mal b/tests/stepA_mal.mal
@@ -163,6 +163,8 @@
 ;=>false
 (macro? :+)
 ;=>false
+(macro? {})
+;=>false
 
 
 ;;