Adding some notes for the Rationale, but still WIP.

diff --git a/rationale.md b/rationale.md
index 392f454..69c43dc 100644 (file)
--- a/rationale.md
+++ b/rationale.md
@@ -6,29 +6,54 @@ Since Whitespace ignores [VTab] as a comment character, and since the
 Whitespace VM is a superset of the VVhitespace VM, all valid VVhitespace
 programs are also valid Whitespace programs.
 
 Whitespace VM is a superset of the VVhitespace VM, all valid VVhitespace
 programs are also valid Whitespace programs.
 

-Locating a Whitespace interpreter capable of running all valid Whitespace
-programs is left as an exercise for the reader. For the inquisitive, the
-following program, read top-down, is both a valid VVhitespace and Whitespace
-program. Does it terminate or infinitely loop?
-
-    [Space]
-    [Space]
-    [Space]
-    [Tab]
-    [LF]
-    [LF]
-    [Space]
-    [LF]
-    [Space]
-    [Tab]
-    [LF]
-    [LF]
-    [Space]
-    [Space]
-    [VTab]
-    [Space]
-    [Tab]
-    [LF]
-    [LF]
-    [LF]
-    [LF]
+--------------------------------------------------------------------------------
+
+TODO: Finish this up based on what I've found below.
+
+It seems that all (most?) WS interpreters locate labels using one of two methods.
+
+  * **Method 1** Scan from the start of the file for the first occurence of the
+    mark-label bytestring and jump.
+
+  * **Method 2** Scan from the start of the file, looking for a mark-label
+    bytestring, but 'parsing' one bytestring at a time, and jumping to the
+    first 'standalone' mark-label bytestring. Note that this is different than
+    executing the program, particularly when user-input commands are present.
+
+Both of these methods can be broken:
+
+  * Type 1: No 'standalone' label exists. This breaks Method 2.
+
+    This should print a '!' before infinite '.' lines.
+
+  * Type 2: Hidden label before 'standalone' label. This breaks Method 1.
+
+    This should print an infinite chain of '.' lines.
+
+This is the Type 1 program:
+
+    SSSTSSSSTN  | Push +33 (ASCII !)
+    NSNSTSTTTSN | JMP>label0
+    NSSTTTTN    | MARK label2
+    SSSSN       | PUSH +0
+    SNN         | DROP
+    SSSTSTTTSN  | Push +46 (ASCII .)
+    TNSS        | Output character
+    SSSTSTSN    | Push +10 (ASCII newline)
+    TNSS        | Output character
+    NSNTTTTN    | JMP>label2
+
+Append this to turn it into the Type 2 program:
+
+    NSSSTSTTTSN | MARK label0 (2nd time)
+    NSNTTTTN    | JMP>label2
+
+WS Interpreter Evaluations:
+
+    Method 1:
+        whitespacers/c: (c) meth0dz
+
+    Method 2:
+        whitespacers/ruby: (c) 2003 by Wayne E. Conrad
+        whitespacers/perl: (c) 2003 Micheal Koelbl
+        whitespacers/haskell: (c) 2003 Edwin Brady