Add sum.g example.

asmg/sum.g

@@ -0,0 +1,49 @@
+# This file is part of asmc, a bootstrapping OS with minimal seed
+# Copyright (C) 2018 Giovanni Mascellani <gio@debian.org>
+# https://gitlab.com/giomasce/asmc
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+const FROM 20
+const TO 0x64
+
+ifun do_sum 2
+
+fun main 0 {
+  "The sum of numbers from " 1 platform_log ;
+  FROM itoa 1 platform_log ;
+  " to " 1 platform_log ;
+  TO itoa 1 platform_log ;
+  " is " 1 platform_log ;
+  FROM TO do_sum itoa 1 platform_log ;
+  "\n" 1 platform_log ;
+}
+
+fun do_sum 2 {
+  $from
+  $to
+  @from 1 param = ;
+  @to 0 param = ;
+
+  $i
+  $sum
+  @i from = ;
+  @sum 0 = ;
+  while i to <= {
+    @sum sum i + = ;
+    @i i 1 + = ;
+  }
+
+  sum ret ;
+}