June 2018 Update

Task/Run-length-encoding/BaCon/run-length-encoding.bacon

@@ -0,0 +1,42 @@
+FUNCTION Rle_Encode$(txt$)
+
+    LOCAL result$, c$ = LEFT$(txt$, 1)
+    LOCAL total = 1
+
+    FOR x = 2 TO LEN(txt$)
+        IF c$ = MID$(txt$, x, 1) THEN
+            INCR total
+        ELSE
+            result$ = result$ & STR$(total) & c$
+            c$ = MID$(txt$, x, 1)
+            total = 1
+        END IF
+    NEXT
+
+    RETURN result$ & STR$(total) & c$
+
+END FUNCTION
+
+FUNCTION Rle_Decode$(txt$)
+
+    LOCAL nr$, result$
+
+    FOR x = 1 TO LEN(txt$)
+        IF REGEX(MID$(txt$, x, 1), "[[:digit:]]") THEN
+            nr$ = nr$ & MID$(txt$, x, 1)
+        ELSE
+            result$ = result$ & FILL$(VAL(nr$), ASC(MID$(txt$, x, 1)))
+            nr$ = ""
+        END IF
+    NEXT
+
+    RETURN result$
+
+END FUNCTION
+
+rle_data$ = "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW"
+
+PRINT "RLEData: ", rle_data$
+encoded$ = Rle_Encode$(rle_data$)
+PRINT "Encoded: ", encoded$
+PRINT "Decoded: ", Rle_Decode$(encoded$)

Task/Run-length-encoding/Ceylon/run-length-encoding.ceylon

@@ -0,0 +1,31 @@
+shared void run() {
+
+    "Takes a string such as aaaabbbbbbcc and returns 4a6b2c"
+    String compress(String string) {
+        if (exists firstChar = string.first) {
+            if (exists index = string.firstIndexWhere((char) => char != firstChar)) {
+                return "``index````firstChar````compress(string[index...])``";
+            }
+            else {
+                return "``string.size````firstChar``";
+            }
+        }
+        else {
+            return "";
+        }
+    }
+
+    "Takes a string such as 4a6b2c and returns aaaabbbbbbcc"
+    String decompress(String string) =>
+            let (runs = string.split(Character.letter, false).paired)
+    		"".join {
+        		for ([length, char] in runs)
+        		if (is Integer int = Integer.parse(length))
+        		char.repeat(int)
+        	};
+
+    assert (compress("aaaabbbbbaa") == "4a5b2a");
+    assert (decompress("4a6b2c") == "aaaabbbbbbcc");
+    assert (compress("WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW") == "12W1B12W3B24W1B14W");
+    assert (decompress("24a") == "aaaaaaaaaaaaaaaaaaaaaaaa");
+}

Task/Run-length-encoding/Elena/run-length-encoding.elena

@@ -0,0 +1,63 @@
+import system'text.
+import system'routines.
+import extensions.
+
+singleton compressor
+{
+    literal compress(literal s)
+    [
+        type<TextBuilder> tb := TextBuilder new.
+        int count := 0.
+        char current := s[0].
+        s forEach(:ch)
+        [
+            if (ch == current)
+            [
+                count += 1
+            ];
+            [
+                tb writeFormatted("{0}{1}",count,current).
+                count := 1.
+                current := ch
+            ]
+        ].
+
+        tb writeFormatted("{0}{1}",count,current).
+
+        ^ tb
+    ]
+
+    literal decompress(literal s)
+    [
+        type<TextBuilder> tb := TextBuilder new.
+        char current := $0.
+        var a := String new.
+        s forEach(:ch)
+        [
+            current := ch.
+            if (current isDigit)
+            [
+                a append(ch)
+            ];
+            [
+                int count := a toInt.
+                a clear.
+
+                tb fill(current,count).
+            ]
+        ].
+
+        ^ tb
+    ]
+}
+
+program =
+[
+    var s := "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW".
+
+    s := compressor compress(s).
+    console printLine(s).
+
+    s := compressor decompress(s).
+    console printLine(s).
+].

Task/Run-length-encoding/Factor/run-length-encoding.factor

@@ -0,0 +1,18 @@
+USING: io kernel literals math.parser math.ranges sequences
+sequences.extras sequences.repeating splitting.extras
+splitting.monotonic strings ;
+IN: rosetta-code.run-length-encoding
+
+CONSTANT: alpha $[ CHAR: A CHAR: Z [a,b] >string ]
+
+: encode ( str -- str )
+    [ = ] monotonic-split [ [ length number>string ] [ first ]
+    bi suffix ] map concat ;
+
+: decode ( str -- str )
+    alpha split* [ odd-indices ] [ even-indices
+    [ string>number ] map ] bi [ repeat ] 2map concat ;
+
+"WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW"
+"12W1B12W3B24W1B14W"
+[ encode ] [ decode ] bi* [ print ] bi@

Task/Run-length-encoding/Julia/run-length-encoding.julia

@@ -0,0 +1,10 @@
+using IterTools
+
+encode(str::String) = collect((length(g), first(g)) for g in groupby(first, str))
+decode(cod::Vector) = join(repeat("$l", n) for (n, l) in cod)
+
+for original in ["aaaaahhhhhhmmmmmmmuiiiiiiiaaaaaa", "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW"]
+    encoded = encode(original)
+    decoded = decode(encoded)
+    println("Original: $original\n -> encoded: $encoded\n -> decoded: $decoded")
+end

Task/Run-length-encoding/Python/run-length-encoding-1.py

@@ -13,10 +13,13 @@ def encode(input_string):
         else:
             count += 1
     else:
-        entry = (character,count)
-        lst.append(entry)
-    return lst
-
+        try:
+            entry = (character,count)
+            lst.append(entry)
+            return (lst, 0)
+        except Exception as e:
+            print("Exception encountered {e}".format(e=e))
+            return (e, 1)
 
 def decode(lst):
     q = ""
@@ -25,5 +28,7 @@ def decode(lst):
     return q
 
 #Method call
-encode("aaaaahhhhhhmmmmmmmuiiiiiiiaaaaaa")
-decode([('a', 5), ('h', 6), ('m', 7), ('u', 1), ('i', 7), ('a', 6)])
+value = encode("aaaaahhhhhhmmmmmmmuiiiiiiiaaaaaa")
+if value[1] == 0:
+    print("Encoded value is {}".format(value[0]))
+    decode(value[0])

Task/Run-length-encoding/Ring/run-length-encoding.ring

@@ -0,0 +1,30 @@
+# Project : Run-length encoding
+# Date    : 2017/12/04
+# Author : Gal Zsolt (~ CalmoSoft ~)
+# Email   : <calmosoft@gmail.com>
+
+load "stdlib.ring"
+test = "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW"
+num = 0
+nr = 0
+decode = newlist(7,2)
+for n = 1 to len(test) - 1
+     if test[n] = test[n+1]
+        num = num + 1
+     else
+        nr = nr + 1
+        decode[nr][1] = (num + 1)
+        decode[nr][2] = test[n]
+        see "" + (num + 1) + test[n]
+        num = 0
+     ok
+next
+see "" + (num + 1) + test[n]
+see nl
+nr = nr + 1
+decode[nr][1] = (num + 1)
+decode[nr][2] = test[n]
+for n = 1 to len(decode)
+     dec = copy(decode[n][2], decode[n][1])
+     see dec
+next

Task/Run-length-encoding/VBA/run-length-encoding.vba

@@ -0,0 +1,37 @@
+Option Explicit
+
+Sub Main()
+Dim p As String
+   p = length_encoding("WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW")
+   Debug.Print p
+   Debug.Print length_decoding(p)
+End Sub
+
+Private Function length_encoding(S As String) As String
+Dim F As String, r As String, a As String, n As Long, c As Long, k As Long
+   r = Left(S, 1)
+   c = 1
+   For n = 2 To Len(S)
+      If r <> Mid(S, n, 1) Then
+         a = a & c & r
+         r = Mid(S, n, 1)
+         c = 1
+      Else
+         c = c + 1
+      End If
+   Next
+   length_encoding = a & c & r
+End Function
+
+Private Function length_decoding(S As String) As String
+Dim F As Long, r As String, a As String
+   For F = 1 To Len(S)
+      If IsNumeric(Mid(S, F, 1)) Then
+         r = r & Mid(S, F, 1)
+      Else
+         a = a & String(CLng(r), Mid(S, F, 1))
+         r = vbNullString
+      End If
+   Next
+   length_decoding = a
+End Function