2016-10-07: Add still incorrect try to implement allowing a space in the name. three-witches-space-in-name

Add still incorrect try to implement allowing a space in the name.

diff --git a/examples/enter-three-witches.w b/examples/enter-three-witches.w
--- a/examples/enter-three-witches.w
+++ b/examples/enter-three-witches.w
@@ -5,45 +5,97 @@ exec guile -L $(dirname $(dirname $(real
 define-module : examples enter-three-witches
 
 use-modules : ice-9 optargs
+              srfi srfi-1
+
+;; FIXME: This version currently does not allow using the same first
+;; name several times. It will need a more refined macro generator
+;; which first gathers all the necessary definitions and then builds
+;; them.
+
+define introduced-names '()
+
+define : say nameparts lines
+       . "Show the lines as said by the name defined by the list
+of name parts.
+       "
+       let 
+         ;; symbols starting with : are not treated as part of the
+         ;; name. They can be used as actor instructions
+         : pure-name : remove (lambda (x) (string-prefix? ":" (symbol->string x))) nameparts
+         if : not : member pure-name introduced-names
+              error 
+                format #f "Tried to use ~A who did not Enter. Introduced names: ~A" 
+                  . pure-name introduced-names
+       format #t "~A\n  ~A\n\n"
+         string-join : map symbol->string nameparts
+         string-join
+           map : lambda (x) (string-join (map symbol->string x))
+               . lines
+           . "\n  "
 
 define-syntax Enter
  syntax-rules ()
-  : _ (name) b ...
+  : _ (name more ...) b ...
     begin
+      ;; process the name: define special syntax for this name (only
+      ;; for the first word of the name, the correctness of the rest
+      ;; of the words is checked at runtime in the say procedure)
       define-syntax name
-        syntax-rules ::: ()
-          : _ (c :::) d :::
-            format #t "~A\n  ~A\n\n" 
-               string-join 
-                 string-split (symbol->string 'name) #\_
-               string-join 
-                 map : lambda (x) (string-join (map symbol->string x))
-                       quote : (c :::) d :::
-                 . "\n  "
-          : _ c d :::
-            ;; allow for modifier keywords after the name
+        syntax-rules ::: (more ...)
+          ;; Support form for modifiers: enclose by double parens (used later)
+          ;; when using this name, print all lines indented, with the name in front.
+          : _ more ... ((mod :::)) (word :::) line :::
+            say
+              ` name more ... mod :::
+              quote : (word :::) line :::
+          ;; extend mod keywords
+          : _ more ... ((mod :::)) modifier line :::
             begin
-              format #t "~A:\n" : symbol->string 'c
-              name d :::
-          : _ c :::
-            begin #t c :::
+              ;; extend the modifier keyword list
+              name ((mod ::: modifier)) line :::
+          ;; say form without modifier
+          : _ more ... (word :::) line :::
+            say
+              ' name more ...
+              quote : (word :::) line :::
+          ;; first modifier keyword after the name
+          : _ more ... modifier line :::
+            begin
+              ;; append to mod helper form
+              name ((modifier)) line :::
+          ;; Strip the name from lines with empty arguments
+          : _ more ... symbol :::
+            begin #t symbol :::
+          ; : _ more ... symbol :::
+          ;   syntax-error
+          ;     . "Name not introduced:" name more ...
+      ;; process the rest of the names
       Enter b ...
+      ;; record that the name was introduced. I do not see a way to do
+      ;; this directly in the compiler, therefore it is checked later
+      ;; during runtime.
+      set! introduced-names : cons '(name more ...) introduced-names
+      ;; add debug output, must be added it here, not in front
+      ; write 
+      ;   quote : list Enter (name more ...) b ...
+      ; newline
   : _ b ...
     begin 
 
 
 define : main args
-  Enter : First_Witch
-          Second_Witch
-          Third_Witch
+  Enter : First Witch
+          Second Witch
+          Third Witch
   
-  First_Witch
+  First Witch
       When shall we three meet again
       In thunder, lightning, or in rain?
   
-  Second_Witch
+  Second Witch
       When the hurlyburly's done,
       When the battle's lost and won.
 
-  Third_Witch
+  Third Witch
       That will be ere the set of sun.
+