Data update

Task/Gray-code/Ada/gray-code.adb

@@ -0,0 +1,47 @@
+with Ada.Text_IO, Interfaces;
+use Ada.Text_IO, Interfaces;
+
+procedure Gray is
+
+   Bits : constant := 5; -- Change only this line for 6 or 7-bit encodings
+   subtype Values is Unsigned_8 range 0 .. 2 ** Bits - 1;
+   package Values_Io is new Ada.Text_IO.Modular_IO (Values);
+
+   function Encode (Binary : Values) return Values is
+   begin
+      return Binary xor Shift_Right (Binary, 1);
+   end Encode;
+   pragma Inline (Encode);
+
+   function Decode (Gray : Values) return Values is
+      Binary, Bit : Values;
+      Mask        : Values := 2 ** (Bits - 1);
+   begin
+      Bit    := Gray and Mask;
+      Binary := Bit;
+      for I in 2 .. Bits loop
+         Bit    := Shift_Right (Bit, 1);
+         Mask   := Shift_Right (Mask, 1);
+         Bit    := (Gray and Mask) xor Bit;
+         Binary := Binary + Bit;
+      end loop;
+      return Binary;
+   end Decode;
+   pragma Inline (Decode);
+
+   HT : constant Character := Character'Val (9);
+   J  : Values;
+begin
+   Put_Line ("Num" & HT & "Binary" & HT & HT & "Gray" & HT & HT & "decoded");
+   for I in Values'Range loop
+      J := Encode (I);
+      Values_Io.Put (I, 4);
+      Put (": " & HT);
+      Values_Io.Put (I, Bits + 2, 2);
+      Put (" =>" & HT);
+      Values_Io.Put (J, Bits + 2, 2);
+      Put (" => " & HT);
+      Values_Io.Put (Decode (J), 4);
+      New_Line;
+   end loop;
+end Gray;

Task/Gray-code/Euphoria/gray-code.eu

@@ -0,0 +1,34 @@
+function gray_encode(integer n)
+    return xor_bits(n,floor(n/2))
+end function
+
+function gray_decode(integer n)
+    integer g
+    g = 0
+    while n > 0 do
+        g = xor_bits(g,n)
+        n = floor(n/2)
+    end while
+    return g
+end function
+
+function dcb(integer n)
+    atom d,m
+    d = 0
+    m = 1
+    while n do
+        d += remainder(n,2)*m
+        n = floor(n/2)
+        m *= 10
+    end while
+    return d
+end function
+
+integer j
+for i = #0 to #1F do
+    printf(1,"%05d => ",dcb(i))
+    j = gray_encode(i)
+    printf(1,"%05d => ",dcb(j))
+    j = gray_decode(j)
+    printf(1,"%05d\n",dcb(j))
+end for

Task/Gray-code/Pluto/gray-code.pluto

@@ -0,0 +1,19 @@
+local fmt = require "fmt"
+
+local function to_gray(n) return n ~ (n >> 1) end
+
+local function from_gray(g)
+    local b = 0
+    while g != 0 do
+        b ~= g
+        g >>= 1
+    end
+    return b
+end
+
+print("decimal  binary  gray    decoded")
+for b = 0, 31 do
+    fmt.write("  %2d     %05d", b, fmt.bin(b))
+    local g = to_gray(b)
+    fmt.print("   %05d   %05d", fmt.bin(g), fmt.bin(from_gray(g)))
+end

Task/Gray-code/PowerShell/gray-code.ps1

@@ -0,0 +1,35 @@
+# Gray code
+
+function Encode {
+  [OutputType([uint32])]
+  param([uint32]$V)
+
+  return $V -bxor ($V -shr 1)
+}
+
+function Decode {
+  [OutputType([uint32])]
+  param([uint32]$V)
+
+  [uint32]$result = 0
+  while ($V -gt 0) {
+    $result = $result -bxor $V
+    $V = $V -shr 1
+  }
+  return $result
+}
+
+Write-Output "decimal  binary   gray    decoded"
+foreach ($i in 0..31) {
+  [uint32]$g = Encode($i)
+  [uint32]$d = Decode($g)
+  [string]$out = @()
+  $out += "{0, 4}     " -f $i
+  $binS = ([convert]::ToString($i, 2)).PadLeft(5, "0")
+  $out += "$binS   "
+  $binS = ([convert]::ToString($g, 2)).PadLeft(5, "0")
+  $out += "$binS   "
+  $binS = ([convert]::ToString($d, 2)).PadLeft(5, "0")
+  $out += "$binS{0, 4}" -f $d
+  Write-Output $out
+}

Task/Gray-code/VBScript/gray-code.vbs

@@ -0,0 +1,29 @@
+Function Encoder(ByVal n)
+    Encoder = n Xor (n \ 2)
+End Function
+
+Function Decoder(ByVal n)
+    Dim g : g = 0
+    Do While n > 0
+       g = g Xor n
+       n = n \ 2
+    Loop
+    Decoder = g
+End Function
+
+' Decimal to Binary
+Function Dec2bin(ByVal n, ByVal length)
+    Dim i, strbin : strbin = ""
+    For i = 1 to 5
+        strbin = (n Mod 2) & strbin
+        n = n \ 2
+    Next
+    Dec2Bin = strbin
+End Function
+
+WScript.StdOut.WriteLine("Binary -> Gray Code -> Binary")
+For i = 0 to 31
+    encoded = Encoder(i)
+    decoded = Decoder(encoded)
+    WScript.StdOut.WriteLine(Dec2Bin(i, 5) & " -> " & Dec2Bin(encoded, 5) & " -> " & Dec2Bin(decoded, 5))
+Next

Task/Gray-code/VHDL/gray-code-1.vhd

@@ -0,0 +1,14 @@
+LIBRARY ieee;
+USE ieee.std_logic_1164.all;
+
+entity b2g is
+   port(  bin  : in  std_logic_vector (4 downto 0);
+          gray : out std_logic_vector (4 downto 0)
+        );
+end b2g ;
+
+architecture rtl of b2g is
+  constant N : integer := bin'high;
+begin
+  gray <= bin(n) & ( bin(N-1 downto 0) xor bin(N downto 1));
+end architecture rtl;

Task/Gray-code/VHDL/gray-code-2.vhd

@@ -0,0 +1,17 @@
+LIBRARY ieee;
+USE ieee.std_logic_1164.all;
+
+entity g2b is
+   port(  gray : in     std_logic_vector (4 downto 0);
+          bin  : buffer std_logic_vector (4 downto 0)
+        );
+end g2b ;
+
+architecture rtl of g2b is
+  constant N : integer := bin'high;
+begin
+  bin(N) <= gray(N);
+  gen_xor: for i in N-1 downto 0 generate
+    bin(i) <= gray(i) xor bin(i+1);
+  end generate;
+end architecture rtl;