Add Elixir Integer module

Signed-off-by: Daniel Kukula <[email protected]>

Author: dkuku

libs/exavmlib/lib/CMakeLists.txt

@@ -29,6 +29,7 @@ set(ELIXIR_MODULES
     Console
     GPIO
     I2C
+    Integer
     LEDC
     Access
     Enum

libs/exavmlib/lib/Integer.ex

@@ -0,0 +1,61 @@
+# This file based on elixir-lang Integer module.
+#
+# Copyright 2012-2022 Elixir Contributors
+# https://github.com/elixir-lang/elixir/commits/v1.14.3/lib/elixir/lib/integer.ex
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+defmodule Integer do
+  @compile {:autoload, false}
+  @moduledoc """
+  This module provides functions for working with integers.
+  This is not a full implementation of the Elixir Integer module.
+  """
+
+  def floor_div(dividend, divisor) do
+    if dividend * divisor < 0 and rem(dividend, divisor) != 0 do
+      div(dividend, divisor) - 1
+    else
+      div(dividend, divisor)
+    end
+  end
+
+  def gcd(integer1, integer2) when is_integer(integer1) and is_integer(integer2) do
+    gcd_positive(abs(integer1), abs(integer2))
+  end
+
+  defp gcd_positive(0, integer2), do: integer2
+  defp gcd_positive(integer1, 0), do: integer1
+  defp gcd_positive(integer1, integer2), do: gcd_positive(integer2, rem(integer1, integer2))
+
+  def mod(dividend, divisor) do
+    remainder = rem(dividend, divisor)
+
+    if remainder * divisor < 0 do
+      remainder + divisor
+    else
+      remainder
+    end
+  end
+
+  def to_charlist(integer, base \\ 10) do
+    :erlang.integer_to_list(integer, base)
+  end
+
+  def to_string(integer, base \\ 10) do
+    :erlang.integer_to_binary(integer, base)
+  end
+end

libs/exavmlib/lib/Kernel.ex

@@ -22,6 +22,21 @@ defmodule Kernel do
   # This avoids crashing the compiler at build time
   @compile {:autoload, false}
 
+  @doc """
+  Returns an integer which is the arithmetical absolute value of `number`.
+
+  ## Examples
+    iex> abs(3)
+    3
+    iex> abs(-3)
+    3
+  """
+  def abs(number), do: :erlang.abs(number)
+
+  def div(dividend, divisor), do: :erlang.div(dividend, divisor)
+
+  def rem(dividend, divisor), do: :erlang.rem(dividend, divisor)
+
   def inspect(term, opts \\ []) when is_list(opts) do
     case term do
       t when is_atom(t) ->