[R] how to pass 'raw' values with cfunction()?

[Dirk Eddelbuettel]

On 17 March 2012 at 14:34, Dan Kelley wrote:
| I am having trouble handing "raw" data to a C function, using "cfunction", as demonstrated in the function and output pasted below.  Can anyone suggest what I'm doing incorrectly?  Thanks.  Dan Kelley [Dalhousie University].

Don't use the .C convention:

R> library(inline)
R> 
R> code <- 'Rprintf("inside f(), b is 0X%x\\n", *b);'
R> f <- cfunction(sig=signature(b="raw"),
+                body=code,
+                convention=".C")
R> b <- as.raw(0x0f)
R> for (i in 1:5)
+     f(b)
inside f(), b is 0X90
inside f(), b is 0X80
inside f(), b is 0X70
inside f(), b is 0X60
inside f(), b is 0X30
R> 
R> f2 <- cfunction(sig=signature(b="raw"), body='
+    Rprintf("inside f(), b is 0X%x\\n", AS_RAW(b));
+    return(R_NilValue);
+ ')
R> b <- as.raw(0x0f)
R> for (i in 1:5)
+     f2(b)
inside f(), b is 0X39bf9e8
inside f(), b is 0X39bf9e8
inside f(), b is 0X39bf9e8
inside f(), b is 0X39bf9e8
inside f(), b is 0X39bf9e8
R> 
R> 

Dirk

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