Regarding use of parenthesis, it is true that R is much better with f(10) != f[10] != f[[10]], where Matlab is a little confusing. Also, in Matlab, you can use some functions without (), further adding to the confusion (the only example that comes to my mind in R is the use of '?' as shortcut for help()).
However, there is still a double use of () in R: it is both used for enclosing function arguments and for grouping operations. One language has a syntax that makes a totally unambiguous use of [], () and {} is Mathematica: [] is for subscript, {} is for function arguments and () is for grouping... but Mathematica code is really a pain to typeset and read.
So, all in all, I really like the S langage syntax: it is very readable and reasonably rigid...
Regarding T and F, I took the habit to *always* type them TRUE or FALSE. Again, very readable and not confusing at all. If T and F as equivalent to TRUE and FALSE would ever be deprecated and then defunct in further versions of R, well, I would not complain about it!
The only aspect I don't like is a too loosely use of the dot in functions: both in functions names, in object classes and in generic functions / methods. Hence, we have for instance: 'data.frame', 'help.search' and 'summary.matrix'... just guess which one is an object class, which one is an ordinary function and which one is a S3 method (OK, S4 solves somehow the problem)? It would have been much better to *reserve* the use of a dot in a function name as a separator between the name of the generic function and the class to which it applies. Thus, 'summary.matrix' would have been correct, but both 'data.frame' and 'help.search' should have been spelled differently, perhaps 'dataframe' and 'helpSearch'. Just a dream... because 'data.frame' will of course never be spelled differently!!!
Best,
Philippe Grosjean
Jan T. Kim wrote:
On Fri, May 20, 2005 at 08:14:24AM -0400, Liaw, Andy wrote:
From: Robin Hankin
On May 20, 2005, at 11:00 am, Jan T. Kim wrote:
On Thu, May 19, 2005 at 03:10:53PM -0400, John Fox wrote:
Since you can use variables named c, q, or t in any event, I don't see why
the existence of functions with these names is much of an
impediment.
True, particularly since I'm not too likely to use these
variables for
(local)
functions, and variables of other types don't prevent
functions from
working.
(I thought this was a problem... I must be spoilt by
recently having
to read
too much Matlab code, where parentheses are used to both enclose subscripts and
parameter lists, thus rendering subscript expressions and function calls
syntactically indistinguishable.)
Heh, I'm a recovering Matlab user too. This is sooooooooooo true!
In Matlab:
f(10) # function f() evaluated at 10 f(10) # 10th element of vector f. confusing!!
R uses round brackets in two unrelated ways:
4*(1+2) --- using "(" and ")" to signify grouping f(8) function f() evaluated at 8.
where there is no reason to use the same parenthesis symbol for both tasks.
The same is done in Fortran/C/C++/Java/Python and God knows how many others...
And this is different from the subscripting / function call ambiguity, as these languages (to the extent I know them) are designed such that parentheses for precedence control are syntactically distinguishable from those used for function parameter lists: If the opening parenthesis is preceded by an identifier, that identifier is a function name and the parenthesis opens a parameter list.
(Python is a somewhat messy case, though, because it uses parentheses for tuples too.)
Best regards, Jan
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