prelude: slimmed and prettified

assets/prelude.h

@@ -1,12 +1,12 @@
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 
 struct Int;
 struct String;
-struct Closure;
 union Value;
 
-enum Tag { VOID, INT, STRING, CLOSURE, CELL, ENV };
+enum Tag { INT, FLOAT, STRING };
 
 typedef union Value (*Lambda)() ;
 
@@ -15,50 +15,36 @@ struct Int {
   int value;
 };
 
+struct Float {
+  enum Tag t;
+  float value;
+};
+
 struct String {
   enum Tag t;
   char* value;
 };
 
-struct Closure {
-  enum Tag t;
-  Lambda lam;
-  void* env;
-} ;
-
-struct Env {
-  enum Tag t;
-  void* env;
-};
-
-struct Cell {
-  enum Tag t;
-  union Value* addr;
-} ;
-
 union Value {
   enum Tag t;
-  struct Int z;
+  struct Int i;
+  struct Float f;
   struct String s;
-  struct Closure clo;
-  struct Env env;
-  struct Cell cell;
 } ;
 
 typedef union Value Value;
 
-static Value MakeClosure(Lambda lam, Value env) {
+static Value MakeInt(int n) {
   Value v;
-  v.clo.t = CLOSURE;
-  v.clo.lam = lam;
-  v.clo.env = env.env.env;
+  v.i.t = INT;
+  v.i.value = n;
   return v;
 }
 
-static Value MakeInt(int n) {
+static Value MakeFloat(float n) {
   Value v;
-  v.z.t = INT;
-  v.z.value = n;
+  v.f.t = FLOAT;
+  v.f.value = n;
   return v;
 }
 
@@ -69,48 +55,40 @@ static Value MakeString(char* s) {
   return v;
 }
 
-static Value MakePrimitive(Lambda prim) {
-  Value v;
-  v.clo.t = CLOSURE;
-  v.clo.lam = prim;
-  v.clo.env = NULL;
-  return v;
-}
-
-static Value MakeEnv(void* env) {
-  Value v;
-  v.env.t = ENV;
-  v.env.env = env;
-  return v;
-}
-
-
-static Value NewCell(Value initialValue) {
-  Value v;
-  v.cell.t = CELL;
-  v.cell.addr = malloc(sizeof(Value));
-  *v.cell.addr = initialValue;
-  return v;
-}
-
 
 Value sum(Value a, Value b) {
-  return MakeInt(a.z.value + b.z.value);
+  return MakeInt(a.i.value + b.i.value);
 }
 
 Value product(Value a, Value b) {
-  return MakeInt(a.z.value * b.z.value);
+  return MakeInt(a.i.value * b.i.value);
 }
 
 Value difference(Value a, Value b) {
-  return MakeInt(a.z.value - b.z.value);
+  return MakeInt(a.i.value - b.i.value);
 }
 
 Value display(Value v) {
-  printf("%i\n",v.z.value);
+  switch(v.t) {
+    case INT:
+      printf("%d\n",v.i.value);
+      break;
+    case FLOAT:
+      printf("%f\n",v.f.value);
+      break;
+    case STRING:
+      printf("%s\n",v.s.value);
+      break;
+  }
   return v;
 }
 
 Value equal(Value a, Value b) {
-  return MakeInt(a.z.value == b.z.value);
+  if (a.t != b.t) return MakeInt(1);
+  switch(a.t) {
+    case INT: return MakeInt(a.i.value == b.i.value);
+    case FLOAT: return MakeInt(a.f.value == b.f.value);
+    case STRING: return MakeInt(!strcmp(a.s.value, b.s.value));
+  }
+  return MakeInt(0);
 }