My old, deeply flawed mental picture had "iio" taking
the role of a pointer to a value. My bright, shiny
new mental picture has "iio" acting just like a C
#define macro: every time I call "iio", I'm really
just writing "newIORef 0". Is that what you're saying?
-Rod
On Oct 27, 2008, at 4:36 PM, Martijn van Steenbergen wrote:
Rodney D Price wrote:
So apparently my mental picture of an IORef as a pointer
to a value is wrong. I need a new mental picture. What's
going on here?
Naming the creation of a new IORef "iio" is not gonna make it return
the same IORef every time you call iio. Imagine iio being expanded
to its definition in your counter1 example (which is exactly what
happens); would you still expect the result to be 1,1,2,3? If you
want the IORef to be shared by different pieces of code, pass it
around as an argument.
Kind regards,
Martijn.
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