* interp/lexing.boot (indentationLocation): New.

	* interp/macros.lisp (expand-tabs): Use it in lieu of NDENT-POS.
	* interp/preparse.lisp (PREPARSE1): Likewise.

4 files changed, 25 insertions, 22 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index fdf8f767..f900aac6 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,11 @@
 2012-05-06  Gabriel Dos Reis  <gdr@cs.tamu.edu>
 
+	* interp/lexing.boot (indentationLocation): New.
+	* interp/macros.lisp (expand-tabs): Use it in lieu of NDENT-POS.
+	* interp/preparse.lisp (PREPARSE1): Likewise.
+
+2012-05-06  Gabriel Dos Reis  <gdr@cs.tamu.edu>
+
 	* interp/Makefile.in (OBJS): Include io.$(FASLEXT).
 	(io.$(FASLEXT)): New rule.
 	* interp/io.boot: New.
diff --git a/src/interp/lexing.boot b/src/interp/lexing.boot
index 4b357918..36b54fd5 100644
--- a/src/interp/lexing.boot
+++ b/src/interp/lexing.boot
@@ -44,6 +44,22 @@ module lexing where
   matchString: %String -> %Maybe %Short
   matchAdvanceString: %String -> %Maybe %Short
   matchAdvanceKeyword: %Symbol -> %Thing
+  indentationLocation: %String -> %Maybe %Short
+
+--%
+
+++ Return the logical indentation position in the `line', after
+++ expansion of leading vertical tab characters.
+indentationLocation line ==
+  loc := 0
+  n := #line
+  for i in 0.. repeat
+    i >= n => return nil
+    spaceChar? line.i => loc := loc + 1
+    tabChar? line.i => loc := 8 * (loc quo 8 + 1)
+    return loc
+
+--%  
 
 --%
 --% Line abstract datatype
diff --git a/src/interp/macros.lisp b/src/interp/macros.lisp
index 227533d5..c11951cb 100644
--- a/src/interp/macros.lisp
+++ b/src/interp/macros.lisp
@@ -475,29 +475,10 @@ terminals and empty or at-end files.  In Common Lisp, we must assume record size
      (terpri stream)
      (finish-output stream)))
 
-;; moved here from preparse.lisp
-
-(defun NEXT-TAB-LOC (i) (* (1+ (truncate i 8)) 8))
- 
-(defun INDENT-POS (STR)
-  (do ((i 0 (1+ i))
-       (pos 0))
-      ((>= i (length str)) nil)
-      (case (char str i)
-            (#\space (incf pos))
-            (#\tab (setq pos (next-tab-loc pos)))
-            (otherwise (return pos)))))
-
-;;(defun expand-tabs (str)
-;;  (let ((bpos (nonblankloc str))
-;;      (tpos (indent-pos str)))
-;;    (if (eql bpos tpos) str
-;;      (concatenate 'string (make-string tpos :initial-element #\space)
-;;                 (subseq str bpos)))))
 (defun expand-tabs (str)
    (if (and (stringp str) (> (length str) 0))
       (let ((bpos (nonblankloc str))
-            (tpos (indent-pos str)))
+            (tpos (|indentationLocation| str)))
         (setq str 
               (if (eql bpos tpos)
                   str
diff --git a/src/interp/preparse.lisp b/src/interp/preparse.lisp
index 0fd7bc3a..120656b1 100644
--- a/src/interp/preparse.lisp
+++ b/src/interp/preparse.lisp
@@ -133,7 +133,7 @@
                (INSTRING)
                ((= N COMSYM) (setq A (subseq A 0 N)) (GO NOCOMS)) ; discard trailing comment
                ((= N NCOMSYM)
-                (setq SLOC (INDENT-POS A))
+                (setq SLOC (|indentationLocation| A))
                 (COND
                   ((= SLOC N)
                    (COND ((AND NCOMBLOCK (NOT (= N (CAR NCOMBLOCK))))
@@ -150,7 +150,7 @@
                ((= N CPARSYM) (setq PCOUNT (1- PCOUNT))))
          (setq I (1+ N))
          (GO STRLOOP)
- NOCOMS  (setq SLOC (INDENT-POS A))
+ NOCOMS  (setq SLOC (|indentationLocation| A))
          (setq A (DROPTRAILINGBLANKS A))
          (cond ((NULL SLOC) (setq SLOC PSLOC) (GO READLOOP)))
          (cond ((EQ (ELT A (MAXINDEX A)) #\_)