bug in R 2.7.0 (PR#11497)

In the latest version R2.7.0 the following command does not work anymore:

      x <- eval(parse(prompt = paste("give value for x  > ")))

It does give the pompt, but the object x is not created.

We think this is due to a bug in the function parse.

best regards,
Wout Slob

  

parse()

parse()

More succinctly, parse() from stdin() seems to be broken:

parse()

?a
expression()

This was not the case in January (this was the older version I had lying
around):

R version 2.6.2 alpha (2008-01-29 r44233)
....

parse()

?a
expression(a)

Also, if your input starts with certain errors, parse returns
the stuff after the error:

   > parse()

   ?err//one
   expression(one)


After the attached change we get

   > parse()

   ?one
   expression(one)

   > parse(n=2)

   ?one;two;three
   expression(one, two)

   > parse()

   ?err//one
   Error in parse() : unexpected '/' in "err//"

Index: gram.y
===================================================================
--- gram.y	(revision 45762)
+++ gram.y	(working copy)
@@ -1389,8 +1389,6 @@
 	    if (c == ';' || c == '\n') break;
 	}

-	rval = R_Parse1Buffer(buffer, 1, status);
-
 	/* Was a call to R_Parse1Buffer, but we don't want to reset xxlineno and xxcolno */
 	ParseInit();
 	ParseContextInit();

On Thu, 22 May 2008, Bill Dunlap wrote:

Also, if your input starts with certain errors, parse returns
the stuff after the error:

   > parse()

   ?err//one
   expression(one)


After the attached change we get

   > parse()

   ?one
   expression(one)

   > parse(n=2)

   ?one;two;three
   expression(one, two)

   > parse()

   ?err//one
   Error in parse() : unexpected '/' in "err//"

Index: gram.y
===================================================================
--- gram.y	(revision 45762)
+++ gram.y	(working copy)
@@ -1389,8 +1389,6 @@
 	    if (c == ';' || c == '\n') break;
 	}

-	rval = R_Parse1Buffer(buffer, 1, status);
-
 	/* Was a call to R_Parse1Buffer, but we don't want to reset xxlineno and xxcolno */
 	ParseInit();
 	ParseContextInit();

The bug arose 2008-02-14, revision 44472, src/main/gram.y,
where it looks like it was intended that the call to
R_Parse1Buffer be replaced by most of the contents of
R_Parse1Buffer, but the the call itself was not removed
(the comment says it was).  My change makes the comment
true.

@@ -1400,6 +1406,12 @@

        rval = R_Parse1Buffer(buffer, 1, status);

+       /* Was a call to R_Parse1Buffer, but we don't want to reset xxlineno and x
xcolno */
+       ParseInit();
+       ParseContextInit();
+       R_Parse1(status);
+        rval = R_CurrentExpr;
+
        switch(*status) {