utils: vlq

Author: krishpranav

src/utils/vlq.cr

@@ -0,0 +1,40 @@
+# -----------------------------------------------------------------------
+# This file is part of MoonScript
+#
+# MoonSript 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.
+#
+# MoonSript 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 MoonSript.  If not, see <https://www.gnu.org/licenses/>.
+#
+# Copyright (C) 2025 Krisna Pranav, MoonScript Developers
+# -----------------------------------------------------------------------
+
+module MoonScript
+  module VLQ
+    VLQ_BASE_SHIFT       = 5
+    VLQ_BASE             = 1 << VLQ_BASE_SHIFT
+    VLQ_BASE_MASK        = VLQ_BASE - 1
+    VLQ_CONTINUATION_BIT = VLQ_BASE
+
+    def self.encode(int)
+      vlq = to_vlq_signed(int)
+      encoded = ""
+      cond = True
+
+      while cond
+        digit = vlq & VLQ_BASE_MASK
+        vlq >>= VLQ_BASE_SHIFT
+        digit |= VLQ_CONTINUATION_BIT if vlq > 0
+        cond = vlq > 0
+      end
+    end
+  end
+end