✨ if function.

features/cond.mk

@@ -0,0 +1,12 @@
+(assert-eqv! 4 (if true 4 6))
+(assert-eqv! 29 (if false 7 29))
+
+(assert-eqv! 7 (if
+	true
+	7
+	(assert-eqv! 0 1)))
+
+(assert-eqv! 4 (if
+	false
+	(assert-eqv! 0 1)
+	4))

lib/builtins.c

@@ -14,6 +14,7 @@ void register_builtins(struct moka* moka)
 
     moka_decl_native(moka, "do", mk_do, -1);
     moka_decl_native(moka, "set!", mk_set_mut, 2);
+    moka_decl_native(moka, "if", mk_if, 3);
 
     moka_decl_native(moka, "<", mk_lt, 2);
     moka_decl_native(moka, "<=", mk_le, 2);
@@ -153,6 +154,26 @@ MOKA mk_set_mut(struct moka* moka, struct vec* args)
     return value;
 }
 
+MOKA mk_if(struct moka* moka, struct vec* args)
+{
+    assert(moka);
+    assert(args);
+
+    MOKA cond = MK_EVAL((MOKA) args->data[0]);
+    MOKA res = 0;
+
+    if (moka_get_bool(moka, cond))
+    {
+        res = MK_EVAL((MOKA) args->data[1]);
+    }
+    else
+    {
+        res = MK_EVAL((MOKA) args->data[2]);
+    }
+
+    return moka_push(moka, res);
+}
+
 // Comparisons
 // ===========
 MOKA mk_lt(struct moka* moka, struct vec* args)

lib/builtins.h

@@ -16,6 +16,10 @@ MOKA mk_assert_eqv_mut(struct moka* moka, struct vec* args);
 MOKA mk_do(struct moka* moka, struct vec* args);
 MOKA mk_set_mut(struct moka* moka, struct vec* args);
 
+// Flow Control
+// ============
+MOKA mk_if(struct moka* moka, struct vec* args);
+
 // Comparisons
 // ===========
 MOKA mk_lt(struct moka* moka, struct vec* args);

lib/moka.c

@@ -757,7 +757,7 @@ MOKA moka_push_bool(struct moka* self, bool value, int line)
     return addr;
 }
 
-float moka_get_bool(struct moka* self, MOKA value)
+bool moka_get_bool(struct moka* self, MOKA value)
 {
     assert(self);
     struct frame* frame = moka_frame(self);

lib/moka.h

@@ -91,7 +91,7 @@ MOKA moka_push_float(struct moka* self, float value, int line);
 float moka_get_float(struct moka* self, MOKA value);
 
 MOKA moka_push_bool(struct moka* self, bool value, int line);
-float moka_get_bool(struct moka* self, MOKA value);
+bool moka_get_bool(struct moka* self, MOKA value);
 
 MOKA moka_push_string(struct moka* self, char const* value, int line);
 char* moka_get_string(struct moka* self, MOKA value);