✨ block with function do.

features/do.mk

@@ -0,0 +1,18 @@
+(define a 4)
+
+(do
+	(assert-eqv! 4 a)
+	(define a 'hello)
+	(assert-eqv! 'hello a)
+
+	(set! a 28)
+	(assert-eqv! 28 a)
+)
+
+(assert-eqv! 4 a)
+
+(do
+	(set! a -63)
+)
+
+(assert-eqv! -63 a)

lib/builtins.c

@@ -12,6 +12,9 @@ void register_builtins(struct moka* moka)
     moka_decl_native(moka, "array", mk_array, -1);
     moka_decl_native(moka, "assert-eqv!", mk_assert_eqv_mut, 2);
 
+    moka_decl_native(moka, "do", mk_do, -1);
+    moka_decl_native(moka, "set!", mk_set_mut, 2);
+
     moka_decl_native(moka, "<", mk_lt, 2);
     moka_decl_native(moka, "<=", mk_le, 2);
     moka_decl_native(moka, ">", mk_gt, 2);
@@ -108,6 +111,48 @@ MOKA mk_assert_eqv_mut(struct moka* moka, struct vec* args)
     return moka_push_bool(moka, true, line);
 }
 
+MOKA mk_do(struct moka* moka, struct vec* args)
+{
+    assert(moka);
+    assert(args);
+
+    MOKA value = 0;
+
+    symtable_open_scope(&moka->symtable);
+
+    for (size_t i=0; i<args->size; i++)
+    {
+        value = MK_EVAL((MOKA) args->data[i]);
+    }
+
+    symtable_close_scope(&moka->symtable);
+
+    return value;
+}
+
+MOKA mk_set_mut(struct moka* moka, struct vec* args)
+{
+    assert(moka);
+    assert(args);
+
+    MOKA mk_name = (MOKA) args->data[0];
+    MOKA value = MK_EVAL((MOKA)args->data[1]);
+
+    struct frame* frame = moka_frame(moka);
+
+    struct value* name = frame->local_values.data[mk_name];
+    struct node* node = name->data.lazy;
+    struct entry* entry = symtable_try_get(
+        &moka->symtable,
+        node->token->value
+    );
+
+    moka_push(moka, value);
+    entry->addr = frame->local_values.size - 1;
+
+    return value;
+}
+
 // Comparisons
 // ===========
 MOKA mk_lt(struct moka* moka, struct vec* args)

lib/builtins.h

@@ -13,6 +13,9 @@ MOKA mk_define(struct moka* moka, struct vec* args);
 MOKA mk_array(struct moka* moka, struct vec* args);
 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);
+
 // Comparisons
 // ===========
 MOKA mk_lt(struct moka* moka, struct vec* args);

lib/moka.c

@@ -401,7 +401,7 @@ MOKA moka_sub(struct moka* self, int count)
                 : -value->data.real;
         }
     }
-    
+
     vec_free(&args);
 
     if (count == 1)
@@ -491,7 +491,7 @@ MOKA moka_div(struct moka* self, int count)
             is_int = false;
         }
     }
-    
+
     vec_free(&args);
 
     if (count == 1)

lib/symtable.c

@@ -99,3 +99,25 @@ struct entry* symtable_try_get(struct symtable* self, char* name)
     return env_try_get(self->root, name);
 
 }
+
+void symtable_open_scope(struct symtable* self)
+{
+    struct env* env = malloc(sizeof(struct env));
+    env_init(env, self->root);
+
+    self->root = env;
+}
+
+void symtable_close_scope(struct symtable* self)
+{
+    assert(self);
+    assert(self->root);
+
+    struct env* env = self->root->parent;
+    self->root->parent = NULL;
+
+    env_free(self->root);
+    free(self->root);
+
+    self->root = env;
+}

lib/symtable.h

@@ -42,4 +42,7 @@ void symtable_declare(struct symtable* self,
 
 struct entry* symtable_try_get(struct symtable* self, char* name);
 
+void symtable_open_scope(struct symtable* self);
+void symtable_close_scope(struct symtable* self);
+
 #endif