Implement FILE-STATUS

[pforth] / fth / file.fth

diff --git a/fth/file.fth b/fth/file.fth
index b71edc5..0017942 100644 (file)
--- a/fth/file.fth
+++ b/fth/file.fth
@@ -61,6 +61,15 @@ create (LINE-TERMINATOR) \n c,
     0 2r> + c!        ( )
 ;
 
     0 2r> + c!        ( )
 ;
 

+: MULTI-LINE-COMMENT ( "comment<rparen>" -- )
+    BEGIN
+        >in @ ')' parse         ( >in c-addr len )
+        nip + >in @ =           ( delimiter-not-found? )
+    WHILE                       ( )
+        refill 0= IF EXIT THEN  ( )
+    REPEAT
+;
+

 }private
 
 \ This treats \n, \r\n, and \r as line terminator.  Reading is done
 }private
 
 \ This treats \n, \r\n, and \r as line terminator.  Reading is done


@@ -108,4 +117,28 @@ create (LINE-TERMINATOR) \n c,
     THEN
 ;
 
     THEN
 ;
 

+: (  ( "comment<rparen>"  -- )
+    source-id
+    CASE
+        -1 OF postpone ( ENDOF
+        0  OF postpone ( ENDOF
+        \ for input from files
+        multi-line-comment
+    ENDCASE
+; immediate
+
+\ We basically try to open the file in read-only mode.  That seems to
+\ be the best that we can do with ANSI C.  If we ever want to do
+\ something more sophisticated, like calling access(2), we must create
+\ a proper primitive.  (OTOH, portable programs can't assume much
+\ about FILE-STATUS and non-portable programs could create a custom
+\ function for access(2).)
+: FILE-STATUS ( c-addr u -- x ior )
+    r/o bin open-file           ( fileid ior1 )
+    ?dup
+    IF                          ( fileid ior1 )
+    ELSE close-file 0 swap      ( 0 ior2 )
+    THEN
+;
+

 privatize
 privatize