June 2018 Update

Task/Rot-13/PowerBASIC/rot-13.powerbasic

@@ -0,0 +1,40 @@
+#COMPILE EXE
+#COMPILER PBWIN 9.05
+#DIM ALL
+
+FUNCTION ROT13(BYVAL a AS STRING) AS STRING
+  LOCAL p AS BYTE PTR
+  LOCAL n AS BYTE, e AS BYTE
+  LOCAL res AS STRING
+
+  res = a
+  p = STRPTR(res)
+  n = @p
+  DO WHILE n
+    SELECT CASE n
+      CASE 65 TO 90
+        e = 90
+        n += 13
+      CASE 97 TO 122
+        e = 122
+        n += 13
+      CASE ELSE
+        e = 255
+    END SELECT
+
+    IF n > e THEN
+      n -= 26
+    END IF
+    @p = n
+    INCR p
+    n = @p
+  LOOP
+FUNCTION = res
+END FUNCTION
+
+'testing:
+
+FUNCTION PBMAIN () AS LONG
+#DEBUG PRINT ROT13("abc")
+#DEBUG PRINT ROT13("nop")
+END FUNCTION