--- gforth/blocks.fs	2000/09/23 15:05:58	1.32
+++ gforth/blocks.fs	2012/12/31 15:25:17	1.62
@@ -1,12 +1,12 @@
 \ A less simple implementation of the blocks wordset. 
 
-\ Copyright (C) 1995,1996,1997,1998,2000 Free Software Foundation, Inc.
+\ Copyright (C) 1995,1996,1997,1998,2000,2003,2006,2007,2008,2011,2012 Free Software Foundation, Inc.
 
 \ This file is part of Gforth.
 
 \ Gforth is free software; you can redistribute it and/or
 \ modify it under the terms of the GNU General Public License
-\ as published by the Free Software Foundation; either version 2
+\ as published by the Free Software Foundation, either version 3
 \ of the License, or (at your option) any later version.
 
 \ This program is distributed in the hope that it will be useful,
@@ -15,8 +15,7 @@
 \ GNU General Public License for more details.
 
 \ You should have received a copy of the GNU General Public License
-\ along with this program; if not, write to the Free Software
-\ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+\ along with this program. If not, see http://www.gnu.org/licenses/.
 
 
 \ A more efficient implementation would use mmap on OSs that
@@ -44,6 +43,10 @@ Variable last-block
 
 $20 Value buffers
 
+\ limit block files to 2GB; gforth <0.6.0 erases larger block files on
+\ 32-bit systems
+$200000 Value block-limit
+
 User block-fid
 User block-offset ( -- addr ) \ gforth
 \G User variable containing the number of the first block (default
@@ -60,27 +63,33 @@ User block-offset ( -- addr ) \ gforth
     buffer-struct buffers * %alloc dup block-buffers ! ( addr )
     buffer-struct %size buffers * erase ;
 
-' block-cold INIT8 chained
+:noname ( -- )
+    defers 'cold
+    block-cold
+; is 'cold
 
 block-cold
 
 Defer flush-blocks ( -- ) \ gforth
 
 : open-blocks ( c-addr u -- ) \ gforth
-    \g Use the file, whose name is given by @i{c-addr u}, as the blocks file.
-    2dup open-fpath-file 0<>
-    if
-	r/w bin create-file throw
-    else
+\g Use the file, whose name is given by @i{c-addr u}, as the blocks file.
+    try ( c-addr u )
+	2dup open-fpath-file throw
 	rot close-file throw  2dup file-status throw bin open-file throw
 	>r 2drop r>
+    endtry-iferror ( c-addr u ior )
+	>r 2dup file-status nip 0= r> and throw \ does it really not exist?
+	r/w bin create-file throw
     then
-    block-fid @ IF  flush-blocks block-fid @ close-file throw  THEN
+    block-fid @ IF
+	flush-blocks block-fid @ close-file throw
+    THEN
     block-fid ! ;
 
 : use ( "file" -- ) \ gforth
     \g Use @i{file} as the blocks file.
-    name open-blocks ;
+    name name-too-short? open-blocks ;
 
 \ the file is opened as binary file, since it either will contain text
 \ without newlines or binary data
@@ -95,7 +104,8 @@ Defer flush-blocks ( -- ) \ gforth
     block-fid @ ;
 
 : block-position ( u -- ) \ block
-    \G Position the block file to the start of block @i{u}.
+\G Position the block file to the start of block @i{u}.
+    dup block-limit u>= -35 and throw
     offset @ - chars/block chars um* get-block-fid reposition-file throw ;
 
 : update ( -- ) \ block
@@ -104,16 +114,17 @@ Defer flush-blocks ( -- ) \ gforth
 
 : save-buffer ( buffer -- ) \ gforth
     >r
-    r@ buffer-dirty @ r@ buffer-block @ 0<> and
+    r@ buffer-dirty @
     if
 	r@ buffer-block @ block-position
 	r@ block-buffer chars/block  r@ buffer-fid @  write-file throw
-	r@ buffer-dirty off
+	r@ buffer-fid @ flush-file throw
+	r@ buffer-dirty off 
     endif
     rdrop ;
 
 : empty-buffer ( buffer -- ) \ gforth
-    buffer-block off ;
+    dup buffer-block on buffer-dirty off ;
 
 : save-buffers  ( -- ) \ block
     \G Transfer the contents of each @code{update}d block buffer to
@@ -139,7 +150,7 @@ Defer flush-blocks ( -- ) \ gforth
 : get-buffer ( u -- a-addr ) \ gforth
     0 buffers um/mod drop buffer-struct %size * block-buffers @ + ;
 
-: block ( u -- a-addr ) \ gforthman- block
+: block ( u -- a-addr ) \ block
     \G If a block buffer is assigned for block @i{u}, return its
     \G start address, @i{a-addr}. Otherwise, assign a block buffer
     \G for block @i{u} (if the assigned block buffer has been
@@ -177,7 +188,7 @@ Defer flush-blocks ( -- ) \ gforth
     block ;
 
 User scr ( -- a-addr ) \ block-ext s-c-r
-    \G @code{User} variable -- @i{a-addr} is the address of a cell containing
+    \G @code{User} variable containing
     \G the block number of the block most recently processed by
     \G @code{list}.
 0 scr !
@@ -197,11 +208,27 @@ User scr ( -- a-addr ) \ block-ext s-c-r
     dup scr !
     ." Screen " u.
     scr @ updated?  0= IF ." not "  THEN  ." modified     " cr
-    16 0
+    l/s 0
     ?do
-	i 2 .r space scr @ block i 64 * chars + 64 type cr
+	i 2 .r space scr @ block i c/l * chars + c/l type cr
     loop ;
 
+[IFDEF] current-input
+:noname  2 <> -12 and throw >in ! blk ! ;
+                              \ restore-input
+:noname  blk @ >in @ 2 ;      \ save-input
+:noname  2 ;                  \ source-id "*a block*"
+:noname  1 blk +! 1 loadline +! >in off true ;      \ refill
+:noname  blk @ block chars/block ;  \ source
+
+Create block-input   A, A, A, A, A,
+
+: load  ( i*x u -- j*x ) \ block
+    \g Text-interpret block @i{u}.  Block 0 cannot be @code{load}ed.
+    dup 0= -35 and throw
+    block-input 0 new-tib dup loadline ! blk !  s" * a block*" loadfilename 2!
+    ['] interpret catch pop-file throw ;
+[ELSE]
 : (source)  ( -- c-addr u )
   blk @ ?dup
   IF    block chars/block
@@ -212,17 +239,16 @@ User scr ( -- a-addr ) \ block-ext s-c-r
 \G @i{c-addr} is the address of the input buffer and @i{u} is the
 \G number of characters in it.
 
-: load ( i*x n -- j*x ) \ block
-    \G Save the current input source specification. Store @i{n} in
-    \G @code{BLK}, set @code{>IN} to 0 and interpret. When the parse
-    \G area is exhausted, restore the input source specification.
-    loadfilename# @ >r
-    2 loadfilename# ! \ "\a block/"
+: load ( i*x u -- j*x ) \ block
+    \g Text-interpret block @i{u}.  Block 0 cannot be @code{load}ed.
+    dup 0= -35 and throw
+    s" * a block*" loadfilename>r
     push-file
     dup loadline ! blk ! >in off ['] interpret catch
     pop-file
-    r> loadfilename# !
+    r>loadfilename
     throw ;
+[THEN]
 
 : thru ( i*x n1 n2 -- j*x ) \ block-ext
     \G @code{load} the blocks @i{n1} through @i{n2} in sequence.
@@ -263,7 +289,7 @@ User scr ( -- a-addr ) \ block-ext s-c-r
 \     0= IF  block-included  ELSE  included  THEN ;
 
 get-current environment-wordlist set-current
-true constant block
+true constant block \ environment- environment
 true constant block-ext
 set-current