microscript: add core:range()

1 files changed, 34 insertions, 0 deletions

diff --git a/uscript/uscript.c b/uscript/uscript.c
index a7e3ca1..0e6fc4b 100644
--- a/uscript/uscript.c
+++ b/uscript/uscript.c
@@ -36,12 +36,46 @@ void core_len(int argc)
         }
 }
 
+void core_range_next(int argc)
+{
+        (void)argc;
+
+        struct us_cfunc *cfunc = get_cfunc(vm_get(-1));
+        double min = get_num(cfunc_get_upval(cfunc, 0));
+        double max = get_num(cfunc_get_upval(cfunc, 1));
+
+        if (min == max) {
+                vm_push(create_zilch());
+                return;
+        }
+
+        vm_push(create_num(min));
+
+        int inc = max > min ? 1 : -1;
+        cfunc_set_upval(cfunc, 0, create_num(min + inc));
+}
+
+void core_range(int argc)
+{
+        if (vm_get(1).type != VAL_NUM || vm_get(2).type != VAL_NUM)
+                log_fatal(1, "core:range expected two numbers");
+
+        struct us_str *str = copy_str("rangenext", -1);
+        struct us_cfunc *cfunc = create_cfunc(str, core_range_next, 0);
+
+        for (int i = 0; i < argc; i++)
+                cfunc_add_upval(cfunc, vm_get(i));
+
+        vm_push(wrap_cfunc(cfunc));
+}
+
 void us_init(void)
 {
         init_vm();
 
         us_set_cfunc("core:len", core_len, 1);
         us_set_cfunc("core:log", core_print, 1);
+        us_set_cfunc("core:range", core_range, 2);
 }
 
 void us_deinit(void)