Message-ID: <46322D82.6030108@stats.uwo.ca>
Date: 2007-04-27T17:06:10Z
From: Duncan Murdoch
Subject: parsing difference between 2.4.1 and 2.5.0
In-Reply-To: <46322AEE.60100@stats.uwo.ca>
On 4/27/2007 12:55 PM, Duncan Murdoch wrote:
> On 4/27/2007 11:34 AM, Gabor Grothendieck wrote:
>> I noticed the following difference in parse(text = ...) between R
>> 2.4.1 and R 2.5.0.
>>
>> ===
>>
>>> parse(text = "\"^\" (x ,2 )")
>> expression(x^2)
>>> R.version.string
>> [1] "R version 2.4.1 Patched (2006-12-30 r40331)"
>>
>>
>> ====
>>
>>> parse(text = "\"^\" (x ,2 )")
>> expression("^" (x ,2 ))
>>> R.version.string
>> [1] "R version 2.5.0 RC (2007-04-16 r41194)"
>>
>> ====
>>
>> Ryacas was depending on the behavior in R 2.4.1 so the new
>> behavior breaks it.
>>
>> Is this intentional? a bug? How do I get the R 2.4.1 output
>> from R 2.5.0 ?
>
> There's no difference in the parsing,
This isn't quite true, of course: in 2.5.0 the default parse output
includes an attribute that references the original source. I think the
rest of what I wrote is right:
the difference is in the printing.
> By default 2.5.0 will echo what you typed, whereas 2.4.1 will deparse.
> You can get the 2.4.1 behaviour using options(keep.source=F) or
> parse(text = "\"^\" (x ,2 )", srcfile=NULL) (as ?parse says).
>
> Duncan Murdoch
>
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